control i/o system installation guide 3bdd010421r0101 7 connecting the fieldbus to the termination...

ControlIT S900 I/O System

Installation Guide

Manual

S900 I/O System Installation Guide

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ControlIT S900 I/O System

Installation Guide

Manual


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NOTICE The information in this document is subject to change without notice and should not be construed as a commitment by ABB. ABB assumes no responsibility for any errors that may appear in this document.

In no event shall ABB liable for direct, indirect, special, incidental or consequential damages of any nature or kind arising from the use of this document, nor shall ABB be liable for incidental or consequential damages arising from use of any software or hard-ware described in this document.

This document and parts thereof must not be reproduced or copied without written per-mission from ABB, and the contents thereof must not be imparted to a third party nor used for any unauthorized purpose.

The software or hardware described in this document is furnished under a license and may be used, copied, or disclosed only in accordance with the terms of such license.

Copyright © 2002 ABB All rights reserved.

Release: December 2002 Document number: 3BDD010421R0101 Rev. B

CE MARKING This product meets the requirements specified in EMC Directive 89/336/EEC and in Low Voltage Directive 73/23/EEC.

The products for use in hazardous areas (Ex-devices) comply with the ATEX Directive to 94/9 EC.

TRADEMARKS FieldController is a registered trademark of ABB Automation Products GmbH, Germany. PROFIBUS and PROFIBUS-DP are trademarks of PROFIBUS International (P.I.). HART is a trademark of HART Communication Foundation.

http://www.profibus.com/

http://www.profibus.com/

http://www.hartcomm.org/


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TABLE OF CONTENTS

NOTICE ........................................................................................................ 4 CE MARKING ............................................................................................... 4 TRADEMARKS............................................................................................. 4

TABLE OF CONTENTS........................................................................................... 5

1. About this document................................................................................. 9

2. Applicable reference documents........................................................... 10

3. Safety and precautions........................................................................... 11

Safe operation ........................................................................................................ 11 Qualified personnel................................................................................................. 12

4. Introduction.............................................................................................. 13

System features...................................................................................................... 13 System limitations................................................................................................... 15

5. S900 System installation sites ............................................................... 16

Hazardous areas .................................................................................................... 16 Classification of hazardous areas............................................................... 16 Installing the S900 I/O System in a non-hazardous area ........................... 17 Installing the S900 I/O System in Zone 2 ................................................... 19 Installing the S900 I/O System in Zone 1 ................................................... 22

6. Fieldbus.................................................................................................... 24

Fieldbus design with electrical lines ....................................................................... 24


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Fieldbus in S900 I/O system applications Type N...................................... 24 Fieldbus in S900 I/O System applications type S....................................... 28

Fieldbus design with fiber-optic lines...................................................................... 33 General ....................................................................................................... 33 Fiber types and ranges ............................................................................... 34 Optical connectors ...................................................................................... 34 Application .................................................................................................. 34 Topologies .................................................................................................. 34

Redundancy in the fieldbus system........................................................................ 38 Example 1 ................................................................................................... 39 Example 2 ................................................................................................... 40 Example 3 ................................................................................................... 40 Example 4 ................................................................................................... 40

Powering fieldbus components............................................................................... 41

7. Environmental capabilities and power consumption .......................... 42

Environmental capabilities...................................................................................... 42 Explosion protection ................................................................................... 42 Ambient temperature .................................................................................. 42 Mounting orientation ................................................................................... 43 Atmosphere................................................................................................. 43 Shock and vibration .................................................................................... 44

Power details .......................................................................................................... 44 Power limits................................................................................................. 44 Power details of Ex modules (type S)......................................................... 46 Power details of non-Ex modules (type N) ................................................. 48 Power details of the field housings ............................................................. 50

Procedure ............................................................................................................... 52

8. Mounting and connecting the system................................................... 53

Mounting the termination unit ................................................................................. 53 Connection level overview...................................................................................... 53 Power supply .......................................................................................................... 54

Terminal cover and terminal assignment.................................................... 54 Installation................................................................................................... 55 Power distribution, power system design .................................................. 55

Signal circuits.......................................................................................................... 58 Terminals .................................................................................................... 58 Installation................................................................................................... 59

Fieldbus connection................................................................................................ 60


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Connecting the fieldbus to the termination unit .......................................... 60 Installation................................................................................................... 61 Fieldbus connector ..................................................................................... 61

Field housing .......................................................................................................... 62 Using the empty housing FHxxx................................................................. 62 Using cabinets ............................................................................................ 66

9. Components assembly and commissioning ........................................ 67

Selecting and combining components.................................................................... 67 Notes on explosion protection .................................................................... 67

Power units ............................................................................................................. 68 Power units of type S.................................................................................. 68 Power units of type N.................................................................................. 69

Modules .................................................................................................................. 70 Selecting the modules ................................................................................ 70 Replacing a module .................................................................................... 70 Field circuits ................................................................................................ 70 Number of modules .................................................................................... 70 Slot 71

Communication Interface........................................................................................ 71 Single mode (no redundancy)..................................................................... 71 Redundancy mode...................................................................................... 71 Slot 71 Setting the address..................................................................................... 72

Unlocking and encoding ......................................................................................... 72 Unlocking the modules and the Communication Interfaces ....................... 72 Encoding the housings ............................................................................... 72

Using hand-held terminals (HART)....................................................................... 74

10. Shielding and equipotential bonding .................................................... 76

Introduction............................................................................................................. 76 Basic requirements................................................................................................. 76 Overview................................................................................................................. 77

Termination unit .......................................................................................... 78 Power supply .............................................................................................. 78 Fieldbus ...................................................................................................... 79 Signal circuits.............................................................................................. 81 Field housing............................................................................................... 82

Cable and wire layout ............................................................................................. 82 General ....................................................................................................... 82


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Lightning and overvoltage protection ..................................................................... 83 External lightning protectors ....................................................................... 83 Internal lightning protectors ........................................................................ 84 Overvoltage protection................................................................................ 84 Protection through shield grounding........................................................... 84 Overvoltage protection equipment.............................................................. 84

11. Maintenance, repair, trouble-shooting .................................................. 86

Maintenance ........................................................................................................... 86 Trouble-shooting..................................................................................................... 86 Repairing Ex-devices.............................................................................................. 87

12. List of tables, list of figures.................................................................... 88

List of tables............................................................................................................ 88 List of figures .......................................................................................................... 88


1. About this document

This publication includes Warnings, Cautions and Information issues where appropriate to point out safety-related or other important information. It also includes Tips to point useful hints to the reader. The corresponding symbols should be interpreted as follows:

Warnings indicate the presence of a hazard which could result in personal injury.

Cautions indicate the presence of a hazard which could result in equipment or property damage.

Information alerts the reader to pertinent facts and conditions.

Indicates special conditions for meeting explosion protection requirements.

Although Warning hazards are related to personal injury, and Caution hazards are associated with equipment or property damage, it should be understood that operation of damaged equipment could, under certain operational conditions, result in degraded process performance leading to personal injury or death. Therefore, comply fully with all Warning and Caution notices.

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2. Applicable reference documents

The reference documents listed in the table below include additional information about the S900 I/O system.

Table 2-1 Applicable reference documents

Topics Reference document Technical data of the individual components

ControlIT S900 I/O System Data Sheet Document number 3BDD010420

Manuals of the individual components

Presently available manuals: Digital I/O Modules Document number 3BDD010423 Frequency Modules Document number 3BDD010424 Analog HART I/O Modules Document number 3BDD010425 Temperature Modules Document number 3BDD010426

Connection to open control systems, configuration, parameterization

ControlIT I/O System S900 Communication Interface Manual Document number 3BDD010422

Calculating programs for power evaluation

ControlIT S900 I/O System Engineering Tool Catalog number CD910 (Product CD-ROM incl. manuals)


3. Safety and precautions

Safe operation • Proper and safe operation of the S900 I/O System requires proper

transportation and storage, installation and commissioning by qualified personnel, correct operation, proper use and careful maintenance.

• The S900 I/O System must not be installed in hazardous areas of zone 0. • Observe the type of protection and the special conditions specified on the

S900 system components. • The device must not be reconstructed or changed. • Prior to first use all foreign objects must be removed from the device. • Observe the national regulations for safety and for the prevention of

accidents when performing any work on the device. • Prior to commissioning check the S900 system for proper cabling/wiring

and functioning. Carefully check the wiring and markings of intrinsically safe current circuits. Deliver the appropriate proof for the intrinsic safety of these current circuits.

• When a field housing is used, it must be closed properly after this check and may only be re-opened for service.

The present manual does not supersede the relevant national regulations, standards and directives. These must be observed and have to be applied according to the national conditions.

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Qualified personnel Only personnel familiar with the installation, commissioning, operation and maintenance of the electrical equipment and who have the required qualification are authorized to work on the devices.

The regulations defining the qualification of supervisory staff in charge of maintenance and repair in accordance with IEC/EN60079-17 must be observed.


4. Introduction

System features The S900 I/O System is a remote I/O system for use in hazardous areas. Due to its explosion protection certificates the S900 process I/O system can be installed in both hazardous areas (zone 1 and zone 2) and safe areas. The system provides bus-compatible local inputs and outputs (protection class IP20) for connecting digital and analog field instruments. The system consists of a termination unit accommodating the power units, the Communication Interfaces, and the I/O modules. The passive termination unit ensures power distribution and data transfer, and also provides the connection platform. The power units reliably power the entire S900 I/O System station. One power supply unit is sufficient for normal operation. However, as second (redundant) power unit can be added to improve the system availability.

The Communication Interface handles and controls all data traffic between the I/O modules and the supervisory open control system (OCS) or programmable logic controllers (PLC). The Communication Interfaces (CIPB) can also be provided and used redundantly (line redundancy and coupler redundancy).

Figure 4-1 S900 I/O System

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The termination unit can be installed in the field (when mounted in the appropriate field housing), in a cabinet, or in a rack in the control room. Note that a certified field housing approved for protection type 'Increased safety' (EEx e) must be used when installing the termination unit in a hazardous area. The appropriate ready-made field housings are available for the S900 I/O System. The system is powered via special terminals with increased safety on the termination unit. The power units, the Communication Interfaces, and the I/O modules are plugged into the termination unit and locked automatically. The power units have a built-in shut-off mechanism with automatic locking and can be plugged in/removed under power in zone 1. The field housings may be opened for service and maintenance during operation. The S900 I/O System does not require a pressurized or flameproof enclosure and, therefore, is easy to install and to handle. The termination unit and the power units ensure power supply of the Communication Interfaces and up to 16 I/O modules. The termination unit provides all necessary connections. Thus, only the field connections have to be made by the user. Also, hot swapping of the Communication Interfaces and I/O modules is possible, i.e. these units can be plugged in or removed under power. This ensures good replaceability of all active components, and a high degree of flexibility and user-friendliness. Field instruments with a type of protection up to EEx ia IIC can be connected to the I/O modules. At present, up to 16 I/O modules can be run on the same termination unit. Each I/O module is designed for connecting 2, 4 or 8 field instruments, depending on the respective model. The I/O modules and the underlying field instrument level are powered via the termination unit. All intrinsically safe modules are self-feeding and short-circuit proof. No separate routing level with additional power units is needed. HART communication in the field with all analog S900 I/O modules is possible via a PC or hand-held terminal (HHT). In addition, the special HART variants allow for a consistent HART communication with the open control system (OCS). Cyclic transmission of all HART variables, HART diagnostics and (acyclic) configuration of all HART field instruments is possible. The S900 I/O modules are slot-addressed and, therefore, do not require any settings on the modules themselves. The PROFIBUS address is usually set via three coding switches on the termination unit.


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The S900 Communication Interface, the I/O modules, and the connected HART field instruments are configured and parameterized via the fieldbus network. No additional service bus is required. The Communication Interface and the I/O modules have built-in LEDs allowing for on-site diagnostics. All diagnostic and status indicator LEDs comply with DIN EN 60073 and NAMUR NE44. Additionally, the PROFIBUS diagnostics down to channel level are integrated via the bus.

System limitations The S900 I/O System consists of various termination units which can accommodate up to two power units and up to two Communication Interfaces. Up to 16 I/O modules can be plugged onto one termination unit, depending on the model. The I/O modules are 2-channel, 4-channel or 8-channel modules, depending on the model. Every I/O module type can be plugged into any of the 16 available slots. Refer to section Power details of this manual for details about the maximum configuration of the termination unit and the power limits of the power units.

When using 4-channel HART-modules, communication with up to 64 HART-field devices is possible. Acyclic configuration and parameterization of all field instruments is possible without any limitations. For cyclic data transfer of secondary variables, however, there are limitations resulting from the maximum length of the PROFIBUS datagram. Refer to the manual for analog HART modules (see Applicable reference documents) for details.


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5. S900 System installation sites

Hazardous areas The S900 I/O System is designed for applications requiring no explosion protection and for installations in areas with potentially explosive atmosphere. In order to facilitate the selection of the appropriate S900 I/O System components, the individual scenarios are described in detail in the following sections.

Classification of hazardous areas Hazardous areas are subdivided and classified in zones according to the occurrence of potentially explosive atmospheres. The definitions of these zones comply with IEC/EN60079 Part 10: 'Classification of hazardous areas'. A distinction is made between the following zones:

Zone 0 Areas with a permanent, long-term, or frequent presence of an explosive atmosphere consisting of a mixture of air and flammable substances such as gas, vapors or mist (approximate value: more than 1000 hours / year).

Zone 1 Areas with a likelihood that an explosive atmosphere consisting of a mixture of air and flammable substances such as gas, vapors or mist is present when the equipment is operating (approximate value: between 10 and 1000 hours / year).

Zone 2 Areas with no or little likelihood that an explosive atmosphere consisting of a mixture of air and flammable substances such as gas, vapors or mist is present


i.e. areas where such an atmosphere - if at all - only occurs for a very short time (approximate value: between 0.1 and 10 hours / year)

Non-hazardous areas Areas where potentially explosive atmospheres are not likely to occur at all.

Figure 5-1 Classification of hazardous areas, example

Installing the S900 I/O System in a non-hazardous area

Types Depending on the application, S900 I/O Systems of type N or type S are suitable for installation in a non-hazardous area. Type N is used for processing non-intrinsically safe signals, whereas type S is used for intrinsically safe signals of type "i". The S900 I/O system types are identified by their ordering codes.

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Example: termination unit with 16 analog input modules Ordering code for type N: Termination unit TU921N 16 modules AI930N

Ordering code for type S: Termination unit TU921S 16 modules AI930S

Zone 2

Non-hazardous area

Zone 1

Zone 0

I/O System S900Type S

I/O System S900Type N Isolating

Transformer

Intrinsically safeI/O signals

Intrinsically safe PROFIBUS DP

PROFIBUS DP Standard

Non-intrinsically safe I/O signals

Non-intrinsically safe circuit, installed with increased safety

Open control system

Figure 5-2 Installing the S900 I/O System in a non-hazardous area

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Fieldbus When selecting the S900 I/O System type pay special attention to the fieldbus system instrumentation. The S900 I/O System type N is designed for connection to a standard PROFIBUS DP in accordance with EN50170. An intrinsically safe PROFIBUS DP has to be used with the S900 I/O System model S. Refer to section Fieldbus for details about the structure of the two fieldbus systems.

When selecting the appropriate S900 I/O System (type N or type S) pay special attention to the fieldbus system instrumentation type.

Power supply Refer to the data sheets of the S900 power units and to section Mounting and connecting the system for details about the power supply requirements. Observe the applicable national standards and regulations (e.g. IEC60364: Standard for Electrical Installations of Buildings) when designing and installing the system.

Installing the S900 I/O System in Zone 2

Types If the S900 I/O System is installed in zone 2, type S has to be used. Exclusively connect intrinsically safe I/O signals to the S900 I/O System in this case. Couplers are available for processing non-intrinsically safe signals.

Installation When installing the system in Zone 2, observe EN50021 and IEC/EN60079-14 and use an IP 54 (IEC/EN60529) housing. No separate housing is required, if the installation site (e.g. a cabinet) where the S900 I/O System is installed meets the requirements of protection type IP 54. Observe the specifications in section Power details.

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Fieldbus If the S900 I/O System is installed in zone 2, always use an intrinsically safe PROFIBUS DP. Refer to Section Fieldbus for details about the structure of the fieldbus system.

Power supply Refer to the data sheets of the S900 power units and to section Mounting and connecting the system for details about the power supply requirements. The installation must be in accordance with IEC/EN60079-14: Electrical Installations in Hazardous Areas.


Zone 2

Non-hazardous area

Zone 1

Zone 0


Isolating transformer




To other PROFIBUS DP devices

Open control system

Processing of non-intrinsically safe signals via couplers

Figure 5-3 Installing the S900 I/O System in a hazardous area, zone 2

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Installing the S900 I/O System in Zone 1

Types If the S900 I/O System is installed in zone 1, the system type S has to be used. Exclusively connect intrinsically safe I/O signals to the S900 I/O System in this case. Couplers are available for processing non-intrinsically safe signals.

Installation Exclusively use an approved field housing of protection type 'increased safety EEx "e" ' in accordance with the EC Type Examination Certificate of the termination unit, No. PTB 00 ATEX 2156 U (Item 17 b) for installing the system. Observe the specifications in sections Power details and Field housing .

Special requirements have to be met when installing the S900 I/O System in zone 1. Refer to Sections Power details and Field housing .

Fieldbus If the S900 I/O System is installed in zone 1, always use an intrinsically safe PROFIBUS DP. Refer to Section Fieldbus for details about the structure of the fieldbus system.

Power supply Refer to the data sheets of the S900 power units and to section Mounting and connecting the system for details about the power supply requirements. The installation must be in accordance with IEC/EN60079-14: Electrical Installations in Hazardous Areas.

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Non-hazardous area

Zone 1

Zone 0







Open control system


A enclosure for hazardous area is necessary

Non-hazardous area

Zone 1

Zone 0







Open control system


A enclosure for hazardous area is necessary

Figure 5-4 Installing the S900 I/O System in a hazardous area, zone 1

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6. Fieldbus

This chapter describes the fieldbus design for the S900 I/O system. Depending on the specific application you can use an electrical or combined electrical/optical fieldbus configuration. The selection criteria are to be matched to the application (e. g. range, cost, number of bus stations, explosion protection application, etc.). The chapter contains examples to aid in the selection.

When selecting the fieldbus system you must also consider the application location of the S900 I/O system (refer to section S900 System installation sites).

Fieldbus design with electrical lines

Fieldbus in S900 I/O system applications Type N

Topology The following page shows the design of the fieldbus for the type N version of the S900 I/O system.

Number of bus stations According to EN 50 170 the number of bus stations in the PROFIBUS standard can be up to 127, if every bus segment is limited by repeaters to a maximum of 32 bus stations. It must be observed that master units, repeaters, fiber-optic converters, and operating/diagnostic devices are counted as bus stations. For instrumentation of larger systems, repeaters can be used to:

• increase the number of bus stations that can be connected

• electrically isolate the bus stations

• bridge longer distances


Non-hazardous area

Profibus DP

Bus station without bus termination

Bus station with bus termination

Profibus DP

repeater

S900 I/O

System

S900 I/O

System

More Profibus

DP slaves

S900 I/O

System

S900 I/O

System

S900 I/O

System

Profibus DP

Master

Figure 6-1 Type N fieldbus topology

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Line type The standard PROFIBUS line types according to EN 50 170 Part 8-2 are used as line types for type N applications. Recommended use is line type A, the line type B also described in EN 50 170 is obsolete and should no longer be used. The line parameters according to the following table must be observed.

Table 6-1 Bus line parameters

Parameter Line type A Cable construction Shielded twisted pair Wire cross-section > 0.34 mm² Wire diameter > 0.64 mm Surge impedance 135 to 165 ohms at 3 to 20 MHz Mutual capacitance < 30 pF/m Loop resistance < 110 ohms/km

We recommend the use of ABB lines Type CDN110 as shown in list 10/63 in section 06.46. With the specified line parameters of the standard line (line type A), the bus segment lengths specified in the following table are determined for the respective transmission speeds.

Table 6-2 Line lengths per segment

Transmission speed in kbit/s

9.6 19.2 45.45 93.75 187.5 500 1500

Maximum segment length in m

1200 1200 1200 1200 1000 400 200

Within a PROFIBUS-DP system only a transmission speed can be selected, which is supported by all field devices. Depending on the selected transmission speed, the segment lengths are determined as shown.

Stub lines Generally, passive stub lines are to be avoided.

Programming and diagnostic devices that are connected, for example, during commissioning, are usually connected via own cables that act as stub lines. In such cases you must use active connection variants (e. g. bus terminals, repeaters, active lines, etc.).

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Connectors and bus termination To minimize line reflections and to ensure a defined steady level on the transmission line, the transmission line must be fitted with a termination resistor combination at both ends. When using SUB-D connectors for the bus connections, the termination resistors integrated in the connectors can be used. For the N version of the S900 I/O system we recommend SUB-D connectors from ABB list 10/63 in chapter 6.44. The connector with order number BP910S is only provided for intrinsically safe fieldbus installation of type S version and must not be used here.

It is recommended to use the connector with test jack at the master unit/process control system, in order to facilitate the connection of diagnostic devices.

When designing the fieldbus system, observe also sections Shielding and equipotential bonding and Redundancy in the fieldbus system.


Fieldbus in S900 I/O System applications type S

Topology

MoreProfibusP slaves

us
ProfibusDP
master

S900I/O Systemtype N

S900I/O Systemtype S


D

S900I/O Systemtype N

ProfibusDP

repeater

Bus station withstandard bus termination

Bus station withoutbus termination

S900I/O System

type S


Bus station withintrinsically safebus termination

Standard ProfibusDP

Instrinsically safeProfibus DP

BI912SBI913SBI911S

orBI912S

Non-hazardoarea

Zone 2

Zone 1

Figure 6-2 Type S fieldbus topology

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3BDD010421R0101 29

Intrinsically safe fieldbus system An intrinsically safe PROFIBUS-DP fieldbus system can be realized by using the appropriate certified components. When selecting the individual components you must observe that all components fulfill the requirements of the EC Type Examination Certificates (PTB 00 ATEX 2201 incl. 1st supplement) for RS485 fieldbus system listed for the S900 Process I/O module CI920S with respect to the safety requirements. For this purpose, the following conditions must be guaranteed:

Maximum values: Safety-relevant maximum voltage of each bus station: = 4.2 V Safety-relevant total current of all bus stations: = 2.66 A Concentrated capacitances and inductances are not permitted in the bus segment length. Other notes: In intrinsically safe bus segments only those components must be installed that are marked as intrinsically safe electrical resource or associated electrical resource according to EN 50 020. The entire fieldbus must be electrically isolated from other circuits and must be installed and operated in grounded condition. A ground connection of either of the two conductors A or B along the fieldbus segment is not permitted.

Number of bus stations On the one hand, the maximum number of bus stations is limited by the explosion-protection connection data of the individual bus stations. The top limit of the total current must not be exceeded (refer to section Interconnection). From the functional point of view, the maximum number of bus stations in a bus segment is limited to a maximum of 11 (10 S900 Systems and one fieldbus isolating transformer).

Line type Line type A according to EN 50 039 is to be used with the following linear electric constants: • L‘/R‘ = 15 µH/? • Capacitance per unit length ≤ 250 nF/km • Stranded wire diameter ≥ 0.2 mm


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Furthermore, layout and routing of the bus lines must comply with explosion protection regulations EN 50 014, EN 50 020, and IEC/EN 60 079-14.

We recommend the use of ABB lines with order number CDE110-Ex (color: blue) as shown in list 10/63 in section 06.46.

With the recommended line the bus segment lengths specified in the following table are determined for the respective transmission speeds

Table 6-3 Line lengths per segment

Transmission rate in kbit/s

9.6 19.2 45.45 93.75 187.5 500 1500

Maximum segment length in m

1200 1200 1200 1200 1000 400 200

Stub lines Generally, passive stub lines are to be avoided.

Connectors and bus termination Only the certified ABB connector BP910S is permitted for the connection of intrinsically safe bus segments to the S900 I/O System. Other connectors may interfere with the explosion protection! To minimize line reflections and to ensure a defined steady level on the transmission line, the transmission line must be fitted with a termination resistor at both ends. Connector BP910S contains an integrated switchable termination resistor. However, it must be observed that the integrated termination resistor of the connector is only used on one end of the intrinsically safe bus segment. The termination resistance at the start of a bus segment must always be provided by a fieldbus isolating transformer (BI911S, BI912S, or BI913S).

On standard PRFIBUS-DP segments the same rules apply as for the type N version of the S900 I/O system. Here, too, the use of a connector with test jack at the master unit/process control system is recommendable for diagnostic purposes. When designing the fieldbus system, observe also sections Shielding and equipotential bonding and Redundancy in the fieldbus system.


Interconnection

1

3BDD0

IO 1

IO 2 IO 3 IO n

UO/I 1

UO/I 2 UO/I 3 UO/I n

UO (1...n) ≤ UI (1...n) ≤ 4.2V

∑ IO i ≤ Imax = 2.66An

i=1

2 3 n

Figure 6-3 Interconnection of the intrinsically safe fieldbus

Procedure for interconnecting the components:

Checking the explosion protection:

• Check whether all devices (field devices, repeaters/isolating transformers, fiber-optic components) comply with directive 94/9 EC Category 2 and to these operating instructions.

• Check the maximum possible total current of all bus stations in a fieldbus segment: Σ Io components =2.66 A

• Check the maximum occurring output voltages of all bus stations Uo = 4.2 V.

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32 3BDD010421R0101

• Check the maximum L/R ratio of the cable used. L/R cable =15 µH/ohms (at minimum ambient temperature of the cable)

• Check whether a potential equalization according to EN 60 079-14 12.2.2.3 section b) is present, if required.

Checking the functionality:

• Check whether the number of stations per bus segment = 11 (field devices and repeaters/isolating transformers).

• Check whether the bus segment length matches the transfer rate used. • Check whether a termination resistor is fitted at the start and end of each

bus segment (connector BP910S contains an integrated switchable termination resistor).

Example The following components should be interconnected for application in explosion protected areas: - 1 x fieldbus isolating transformer BI1913S - 10 x S900 I/O system type S version - line ABB CDE110-Ex

1. Checking the suitability

All components listed above comply with EC directive 94/9 and may only be used in explosion hazard areas (refer to EC Type Acceptance Certificates).

2. Total current of all bus station = 2.66 A BI913S : Io = 144 mA S900 CI920S : Io = 157 mA Resulting total current: ΣIo = 144 mA + 10 x 157 mA = 1.714 A < 2.66 A

3. Maximum output voltage of bus stations = 4.2 V BI913S : Uo = 4.1 V S900 CI920S : Uo = 3.75 V

4. L/R ratio of the bus line = 15 µH/ohms

The bus line used (ABB CDE110-Ex) fulfills this requirement.


3BDD010421R0101 33

Fieldbus design with fiber-optic lines

General Features of optical transmission media include:

• immunity against electromagnetic interference • no crosstalk between different fiber-optic signal lines • no noise injection from electrical lines • no interference through electromagnetic fields, such as occurring when

switching high electrical loads • electrical isolation between connected bus stations • no compensating currents between different ground potentials • no special lightning protection measures for the transmission line • ability to cover long distances at high transmission rates with fiber-optic

lines

Substantial components of the optical transmission layer of a bus station are the electro-optical converters forming the link between electrical part of the interface module and the optical network. An optical transmitter converts electrical signals into optical signals and feeds them into the optical network. Vice versa, an optical receiver converts the received optical signals into electrical signals. The connection between bus stations is established via fiber-optic lines (FO) within a topology matched to the application (ring, star, line, or mixed topology).


34 3BDD010421R0101

Fiber types and ranges There are different fiber types with different characteristic features with respect to range, price, and application area. The following table provides an overview.

Table 6-4 Characteristics of fiber-optic lines for PROFIBUS

Fiber type Characteristics Glass fiber 62.5/125 µm Range approx. 2,600 m Glass fiber 50/125 µm Range approx. 1,400 m Plastic fiber 980/1000 µm Range approx. 50 m PCS/HCS fiber 200/230 µm Range approx. 1,000 m

Optical connectors The FO converters available from ABB (BI921S, BI922S, BI923S, BI924S, BI931S1, BI932S1, BI933S1, BI934S1) feature connectors for D-SMA connectors with screw connections.

Application All FO converters available from ABB are suitable for application in hazardous areas of zone 1 and 2.

Topologies In the following, different topologies for designing FO fieldbus systems are shown. Note that in the illustrations the fiber-optic links drawn as single lines are always two physical fibers, one each for signal line and return line.


Optical stub The optical stub is used for covering large distances. As this is a point-to-point connection, further distribution is not possible on the optical path, but can only be realized electrically.

ProfibusDPBus station withIntrinsically safe Non-hazardous

3BD

master

S900I/O

Systemtype S

S900I/O

Systemtype S

MoreProfibus

DP slaves

standard bustermination


S900I/O

Systemtype s

S900I/O

Systemtype S


Standard ProfibusDP

Profibus DP

BI912S

BI921S

area

Zone 1/2

BI921S

BI921S BI931S1

Bus stationFO connection

FO link

Figure 6-4 Fieldbus system with optical stub connection

D010421R0101 35


Optical network The optical network is used for covering larger distances between several bus stations. For the number of bus stations refer to the data sheets of the FO components. Note that in case of a failure on an FO component (e. g. power failure) the downstream optical bus can no longer function.

ProfibusDP

master

S900I/O

Systemtype S

S900I/O

Systemtype S

MoreProfibus

DP slaves

Bus station withstandard bustermination


S900I/O

Systemtype S

S900I/O

Systemtype S


Standard ProfibusDP

Intrinsically safeProfibus DP

BI913SBI913S

BI921S

Non-hazardousarea

Zone 1/2

BI921S

BI922S BI932S1

Bus station withFO connection

FO link

BI921S BI931S1

Figure 6-5 Fieldbus system with an optical network

36 3BDD010421R0101


Optical ring The optical ring is a special form of optical network. The optical ring is also used for covering larger distances between several bus stations. For the number of bus stations refer to the data sheets of the FO components. Unlike the optical network, the function is still maintained in case of a failure of one

Profibus

DPmaster

S900I/O

Systemtype S

S900I/O

Systemtype S

More Profibus

DP slaves



S900I/O

Systemtype S

S900I/O

Systemtype S


Standard Profibus DP

Intrinsically safe Profibus DP

BI913SBI913S

BI924S

Non-hazardous area

Zone 1/2

BI924S

BI923S BI933S1


FO links

BI923S BI933S1

Figure 6-6 Fieldbus system with an optical ring

3BDD010421R0101 37


38 3BDD010421R0101

fiber-optic link. Please note, that Profibus Master devices are connected via the BI924S resp. BI934S1 and Profibus Slave devices are connected via the BI923S resp. BI933S1 with the optical ring.

Redundancy in the fieldbus system To increase the availability of fieldbus systems, different redundancy types are used. A distinction is made between master, slave, and line redundancy. Master redundancy is established independently of the connected bus stations and, therefore, is not described here any further. The following section details the physical design of the combined line/slave redundancy supported by the S900 I/O System.

To design line redundancy, it is required that the two bus lines are coupled at or in the master. This coupling must be made in such a way that an error on one bus line does not interfere with the other, still functioning line. For masters not supporting any corresponding line redundancy, the ABB redundancy link module RLM 01 can be used (catalog number 72711-9450165V in list 10/63, section 6.41).

Line redundancy in connection with the S900 I/O system also requires the use of two Communication Interfaces in one S900 I/O System station. To reduce the space requirements and cost and to improve the energy balance (Ex), S900 Communication Interfaces have only one PROFIBUS connection. However, through the use of two Communication Interfaces an additional slave redundancy is established, i. e. the failure or replacement of a Communication Interface does not affect the operation of the system. With respect to configuration and commissioning of the system the corresponding documentation is available (refer to Applicable reference documents).





Standard ProfibusDP

Intrinsically safeProfibus DP


FO link

Profibus DP

master

I/O System S900

redundant type N.

1

Profibus DP

master

Profibus DP

master

BI911S/BI912S/BI913S




BI921S

BI921S

BI931S1or

BI921S +BI913S

RLM 01

I/O SystemS900

redundanttype S

BI931S1or

BI921S +BI913S

I/O SystemS900

redundanttype S

Profibus DP

master

BI924S

BI924S

BI933S1or

BI923S +BI913S

BI933S1or

BI923S +BI913S

I/O SystemS900

redundanttype S.

more fiber-opticbus stations

more fiber-opticbus stations

more S900 I/O Systems


more I/O Systems S900


I/O SystemS900

redundanttype S

2

3

4

Figure 6-7 Examples for redundant configuration of a fieldbus system

Example 1 Here, line redundancy of the electrical fieldbus system with S900 I/O System stations is shown with N type and S type versions. The master has redundant fieldbus connections. Separation between the standard PROFIBUS-DP and the intrinsically safe PROFIBUS-DP is implemented via isolating transformers (see also Fieldbus in S900 I/O System applications type S).

Diagnosing a faulty bus segment is done by the master. Here, the diagnostic messages of slaves that switched to the redundant line can be analyzed.

3BDD010421R0101 39


40 3BDD010421R0101

Example 2 Other than in example 1, the master does not have any redundant fieldbus connections. In order to establish line redundancy despite this fact, the ABB redundancy link module RLM 01 can be used.

Diagnosing a faulty bus segment is again done by the master through analyzing the diagnostic messages of the slaves. In addition, a signaling contact of the RLM 01 could be used.

For details refer to the operating instructions of the RLM 01.

Example 3 Here, line redundancy is shown in connection with an FO stub connection. For FO conversion the components as shown in section Fieldbus design with fiber-optic lines can be used. Note that in the illustrations the fiber-optic links drawn as single lines are always two physical fibers, one each for signal line and return line.

Note:

In case of stub couplers BI921S/BI931S1 there is no automatic deactivation of the opposing fiber-optic line, if one fiber-optic line is interrupted. Therefore, safe diagnosis of an interrupted fiber-optic line is not possible.

Example 4 In this example the fiber-optic link is configured as a ring and not as a stub as in example 3. This arrangement provides extremely high availability. As the optical ring already inherently tolerates a fault in the fiber-optic link (refer also to Optical ring), an FO converter may also fail in a redundant configuration, without affecting the fieldbus.

Diagnosing a defective line can be done again by analyzing the diagnostic messages of the slaves. In addition, the FO converter provide a signal contact for the optical ring for evaluating the availability (this allows diagnosing an interrupted ring).


3BDD010421R0101 41

Powering fieldbus components The optical and electrical fieldbus components Bixxx described here require their own power supply. Depending on the installation location, power can be preferably derived from the power supply of the S900 I/O System or other fieldbus bus stations. Refer to the data sheets and operating instructions of such components for the power supply requirements.

When using these components in hazardous areas, the power supply must be installed in explosion protection type “e” – Increased Safety.


42 3BDD010421R0101

7. Environmental capabilities and power consumption

Environmental capabilities

Explosion protection The S900 I/O System is designed to be installed and used in hazardous areas (zone 1 and zone 2) and safe areas. The intrinsically safe circuits of the input and output modules meet the requirements of categories 1 and 2 (zone 0 and zone 1) in accordance with IEC/EN60079-10. The operative range in accordance with 94/9/EC must be observed.

When the S900 I/O System is installed in hazardous areas, zone 2, it must be accommodated in a subsidiary cabinet with protection class IP 54 or higher to protect it against environmental influences.

When installing the system in zone 1, use a housing that is certified in accordance with the local regulations for the installation of current circuits with increased safety. For details about how to select the appropriate field housing refer to section Power details and to section Mounting and connecting the system.

Ambient temperature The S900 I/O System components are designed for a maximum ambient temperature range of –20…+60°C. Make sure that this temperature range is not exceeded or fallen below, especially when installing the system in housings, cabinets or racks. If necessary, the ambient temperature has to be monitored. The maximum values specified here must be especially observed for applications where explosion protection is required (system type S). Observe the instructions regarding the determination of the power dissipation and the installation of the system in a housing given in section Power details.


The specified ambient temperature range must be observed under all operating conditions to ensure explosion protection and system availability.

When selecting the installation site, make sure that it is possible to observe the necessary clearance from other heat sources. Do not expose the system to direct sun light. Otherwise, the permissible ambient temperature may be exceeded. If required, take the necessary measures to protect the system accordingly. The appropriate covers, which at the same time protect the equipment from weather impact, are available from ABB (catalog number FR100). When designing/installing sun shields observe the different angles of incidence in dependence of the season. Avoid heat accumulation under the sun shields.

Mounting orientation The S900 I/O System is designed for horizontal mounting orientation to ensure optimal heat dissipation/ventilation. Other orientations are not intended.

Atmosphere The parts of the S900 I/O System, including the external metal parts, are made of high-quality materials and ensure protection against corrosion and resistance to chemical substances that may occur in a "normal industrial environment". When using the components in an unknown or aggressive environment, the chemical resistance of the used materials has to be tested explicitly.

All S900 components are either completely sealed or protected through the appropriate varnish. Water condensation due to temperature variations or after the first system cold start is therefore negligible, provided that it only occurs for a short time.

For detailed specifications regarding the operating environment and the system capabilities (e.g. resistance to humidity or corrosive gases) refer to the data sheet of the S900 I/O system (see Applicable reference documents).

3BDD010421R0101 43


Shock and vibration Refer to the S900 System data sheet for the maximum permissible shock and vibration to which the system may be exposed (see Applicable reference documents).

Power details This section describes how to determine the S900 I/O System power consumption and power dissipation. This is important to ensure that the specified operating range is observed and the limit values are not exceeded. The section Procedure contains the relevant instructions for systematic checks.

Power limits The S900 I/O System of type S is provided with a power unit (SA910S) with a max. power output of 45 W. The efficiency is approximately 90%. From this results a maximum total power consumption of the termination unit of approximately 50 watts. This specification is also valid for redundant power units, i.e. a higher power consumption in redundancy mode is not permissible. The system must be equipped in such a way that the total power consumption of all S900 modules and S900 Communication Interfaces does not exceed 45 watts, or 50 watts with the power units.

With an S900 I/O System of type S, the total power consumption of the power units SA910S in an S900 I/O System station must not exceed the power limit of 50 watts.

The S900 I/O System of type N is provided with a power unit (SA910N) with a max. power output of 60 W. The total power consumption of the modules and the Communication Interfaces must not exceed 60 watts, or 65 watts with the power units.

44 3BDD010421R0101


With an S900 I/O System of type N, the total power consumption of the power units SA910N in an S900 I/O System station must not exceed the power limit of 65 watts.

When the S900 I/O System is used in a cabinet or field housing, the power output to the field must be considered when determining the max. permissible ambient temperature, in order to calculate the power dissipation within the field housing. The evaluations and specifications in the following section are based on the following maximum conditions: all channels under full load, no errors, and no short circuits in the field circuit. Additionally, the load of the field devices can be considered for optimization. If the load of the field devices is unknown, the maximum values for which the most disadvantageous load has been taken into account have to be used. The maximum number of modules that can be run on a termination unit is given by the available output power of the power unit.

The total power consumption of all I/O modules and Communication Interfaces must always be smaller than the maximum output power provided by the power unit.

The max. number of S900 components that can be run in a field housing is defined by the maximum permissible power dissipation in the field housing at a given ambient temperature.

The power specifications of the individual S900 components and field housings are listed in the following tables.

3BDD010421R0101 45


46 3BDD010421R0101

Power details of Ex modules (type S) Table 7-1 Power details of Ex modules

Conditions Order No. Type Power consumption

[watts]

Power output to the field [watts]

Power dissipation

[watts] Load of the field device

[ohms]

Field current [mA]

Power unit SA910S PS24-Ex

1 x SA910S 50.00 0.00 5.00 2 x SA910S 50.00 0.00 5.00

Communication Interface CI920S CIPB-Ex 2.50 0.00 2.50 Digital input/output DX910S DIO8-Ex 1.10 0.00 1.10 Valve control module DO910S DO4-Ex 1.80 0.80 1.00 2500 2.00 0.90 1.10 2000 2.20 1.10 1.10 1500 2.30 1.10 1.20 1400 2.50 1.30 1.20 1200 2.90 1.30 1.60 1000 3.00 1.60 1.40 890 3.20 1.70 1.50 780 3.40 1.80 1.60 700 3.50 1.80 1.60 645 3.70 1.70 2.00 620 3.80 1.90 1.90 575 3.90 1.90 2.00 550 4.00 1.90 2.10 510 4.20 2.00 2.20 475 4.30 2.00 2.30 456 4.40 2.10 2.30 440 4.50 2.10 2.40 423 4.60 2.10 2.50 405


3BDD010421R0101 47

Conditions Order No. Type Power consumption

[watts]


Power dissipation


[ohms]

Field current [mA]

4.80 2.20 2.60 380 4.90 2.20 2.70 360 5.00 2.20 2.80 350 5.20 2.20 3.00 310 5.30 2.20 3.10 300 5.60 2.00 3.60 275 Frequency input DP910S FI2-Ex 1.10 0.00 1.10 Analog input AI910S AI4-Ex 2.50 1.20 1.30 20 AI920S AI4I-Ex 3.00 1.20 1.80 20 AI930S AI4H-Ex 2.50 1.20 1.30 20 AI931S AI4H-Ex 0.50 -0.40 0.90 20 Temperature input AI950S TI4-Ex 0.70 0.00 0.70 Analog output AO910S AO4-Ex 2.50 0.16 2.34 100 20

2.50 0.32 2.18 200 20 2.50 0.80 1.70 500 20 2.50 1.12 1.38 700 20

AO920S AO4I-Ex 3.30 0.16 3.14 100 20 3.30 0.32 2.98 200 20 3.30 0.80 2.50 500 20 3.30 1.12 2.18 700 20

AO930S AO4H-Ex

2.50 0.16 2.34 100 20

2.50 0.32 2.18 200 20 2.50 0.80 1.70 500 20 2.50 1.12 1.38 700 20

Maximum values shown in bold characters, no closer examination of load required


48 3BDD010421R0101

Power details of non-Ex modules (type N) Table 7-2 Power details of non-Ex modules

Order No. Conditions

Type Power consumption

[watts]


Power dissipation


[ohms]

Field current [mA]

Power unit SA910N PS24

1 x SA910N 65.00 0.00 5.00 2 x SA910N 65.00 0.00 5.00

Communication Interface CI920N CIPB 2.70 0.00 2.70 Digital input/output DX910N DIO8 1.10 0.00 1.10 Valve control module DO910N DO4 1.80 0.80 1.00 2500 2.00 0.90 1.10 2000 2.20 1.10 1.10 1500 2.30 1.10 1.20 1400 2.50 1.30 1.20 1200 2.90 1.30 1.60 1000 3.00 1.60 1.40 890 3.20 1.70 1.50 780 3.40 1.80 1.60 700 3.50 1.80 1.60 645 3.70 1.70 2.00 620 3.80 1.90 1.90 575 3.90 1.90 2.00 550 4.00 1.90 2.10 510 4.20 2.00 2.20 475 4.30 2.00 2.30 456 4.40 2.10 2.30 440 4.50 2.10 2.40 423 4.60 2.10 2.50 405 4.80 2.20 2.60 380 4.90 2.20 2.70 360


3BDD010421R0101 49

Order No. Conditions

Type Power consumption

[watts]


Power dissipation


[ohms]

Field current [mA]

5.00 2.20 2.80 350 5.20 2.20 3.00 310 5.30 2.20 3.10 300 5.60 2.00 3.60 275 Frequency input DP910N FI2 1.10 0.00 1.10 Analog input AI910N AI4 2.50 1.20 1.30 20 AI920N AI4I 3.00 1.20 1.80 20 AI930N AI4H 2.50 1.20 1.30 20 AI931N AI4H 0.50 -0.40 0.90 20 Temperature input AI950N TI4 0.70 0.00 0.70 Analog output AO910N AO4 2.50 0.16 2.34 100 20

2.50 0.32 2.18 200 20 2.50 0.80 1.70 500 20 2.50 1.12 1.38 700 20

AO920N AO4I 3.30 0.16 3.14 100 20 3.30 0.32 2.98 200 20 3.30 0.80 2.50 500 20 3.30 1.12 2.18 700 20

AO930N AO4H 2.50 0.16 2.34 100 20 2.50 0.32 2.18 200 20 2.50 0.80 1.70 500 20 2.50 1.12 1.38 700 20

Maximum values shown in bold characters, no closer examination of load required


50 3BDD010421R0101

Power details of the field housings According to the specifications in the EC Type Examination Certificate the maximum permissible ambient temperature of the S900 I/O modules and components is 60°C. The average inherent heating of the module has been taken into account for this value. The external ambient temperature at approximately 2 cm above the modules must not exceed 70°C. Otherwise, the permissible internal module temperature may be exceeded. If the boundary conditions specified below are not observed, adherence to this limit value must be monitored. The appropriate equipment has to be provided by the customer.

The table seen below can be used as a guideline in the project planning phase. The listed values were determined by measurement under observance of the maximum internal module temperatures specified in the EC Type Examination Certificate. The specifications are only valid if the stated boundary conditions are observed.

Table 7-3 Maximum permissible power dissipation in the field housing

Maximum ambient temperature of the field housing

30°C 35°C 40°C 45°C

50°C 55°C

Field housing type WxHxD

Maximum permissible power dissipation in the field housing

FH64*S 600x400x200, Stainless steel

41 W 37 W 32 W 27 W 21 W 16 W

FH66*S 600x600x300 Stainless steel

50 W 45 W 39 W 33 W 26 W 20 W

FH68*S 600x800x300, Stainless steel

60 W 54 W 47 W 39 W 31 W 24 W

* 0…9


Boundary conditions: • The position and mounting orientation of the termination unit is given by

the field housing and must not be modified by the customer

• The field housing must be mounted at a minimum spacing of 25 mm from the fastening wall.

• The maximum ambient temperature of the field housing of 55°C must not be exceeded.

• The maximum permissible power dissipation of the field housing (30°C value) must not be exceeded.

• The total power dissipation of additional devices installed in the field housing (e.g. optical fieldbus isolators) must not exceed a maximum value of 5 watts. This power dissipation must be handled in the same way as the power dissipation of a module and has to taken into account when calculating the power requirements.

• The area right above the S900 system must be kept free of any objects.

The total power dissipation of the S900 components (modules, power units, Communication Interfaces) must not exceed the maximum permissible power dissipation of the field housing.

The actual internal temperature of the field housing depends on the local conditions like external radiation (adjacent heat sources, sun light) or dirt accumulation on the field housing. This must be taken into account. If required, the appropriate measures have to be taken by the customer. Observance of the above-stated limit values does not release the user of his duty to monitor the system and check to see that the permissible ambient temperature is not exceeded.

3BDD010421R0101 51


52 3BDD010421R0101

Procedure Follow the instructions below to evaluate/determine the power requirements:

• Step 1: Determine the configuration of every S900 I/O System station (number and type of I/O modules, redundant Communication Interfaces, power units).

• Step 2: Determine the load parameters (load resistance for DO910, AO9xx).

• Step 3: Determine the total power consumption of all I/O modules and Communication Interfaces; it must be smaller than the maximum output power provided by the power unit.

• Step 4: Determine the total power dissipation (S900 I/O System and possible additional components); it must be smaller than the maximum permissible power dissipation of the selected field housing or smaller than the maximum power dissipation that can be carried away under the respective installation conditions (cabinet, switch room).

The S900 Engineering Tool (see Applicable reference documents) can be used for performing the steps listed above.


8. Mounting and connecting the system

Mounting the termination unit The S900 I/O System termination unit is mounted on a stable rack or mounting plate or in a field housing (depending on the application). Fasten the system with 4 screws (M5to M6, galvanized or stainless steel) and spring washers. Secure the screws against loosening. Note that this establishes at the same time the equipotential bonding of the termination unit. Refer to the S900 I/O System data sheet for the exact dimensions of the termination unit and the mounting slots.

Connection level overview The illustration below shows the connection levels of the S900 I/O System termination unit.
Energieversorgung Feldbusanschluss Signalstromkreise
Figure 8-1 Overview of the termination unit connection levels

3BDD010421R0101 53


Power supply

Terminal cover and terminal assignment The power connectors on the termination unit of a type S S900 system are protected by a special cover. Do not open this cover when the system is under power. After having established the power connection, make sure that the cover is closed and fastened properly and reliably.

The power connectors on a termination unit of a type N system are directly accessible.

L+ N- PE L+ N- PE

Figure 8-2 Power terminals on a termination unit with redundancy capability

Use terminals L+, N- and PE for power connection. Two terminals are available for each connection to enable through-connection. The second terminal block is only available on termination units with redundancy capability and is used for connecting a second, independent power source. If a power cable with a protective ground wire is used, this wire must be connected to the PE terminal.

Wires with the following properties can be connected to the power terminals:

Table 8-1 Properties of the connectable power wires

Wire type Cross-sectional area Rigid 0.2 – 2.5 mm²

Flexible 0.2 – 2.5 mm² Flexible with end ferrules 0.25 – 1.5 mm²

54 3BDD010421R0101


Installation When the S900 I/O System is used in a hazardous area, the electrical installation must meet the requirements of the protection type "Increased safety".

The requirements defined in IEC/EN60079-14, especially Section 11 (additional requirements for type of protection "e" – Increased safety) must be met. The terminals are protected by an IP30 cover. Do not open the cover or disconnect the terminals when the system is energized. An exception is only possible when a fire permission is submitted by the plant operator.

Power distribution, power system design

900

F4

Power supply filter SF1

F2

To otherS900 Process I/O

Power supply(power units, UPS)

S2

Max. cable length

F3 S1

To otherS900 Process I/O

Figure 8-3 S900 I/O System power distribution

Setup The illustration above shows the setup of the power system in a schematic diagram. Every S900 I/O System station is connected to the central power supply via a separate line. Every line is fuse-protected (F3, F4) and can be

3BDD010421R0101 55


switched on or off (S1, S2). In redundancy mode, the two power connections of the S900 I/O System must be realized via two separate, independent lines.

Power supply filter When an S900 I/O System of type S is used, a power supply filter must be connected into the circuit between the termination unit and the power supply. In redundancy mode, one filter must be provided for each line. The filters are available from ABB under the ordering code BP901S.

When using an S900 I/O System of type S, connect a power supply filter of type BP901S into the circuit between the termination unit and the power supply.

Power The power requirements and efficiency are important for selecting and dimensioning the power units/UPS systems to be used for the S900 I/O System. The minimum requirements are listed in the table below:

S900 I/O System, type S Mode Number of S900 I/O

Systems * Minimum peak output power

Nominal power

1 >170 W >70W 2 >220W >130W 3 >270W >190W 4 >320W >250W

Redundancy mode

5 >370W >310W

1 >60W >60W 2 >110W >110W 3 >160W >160W 4 >210W >210W

Single mode

5 >260W >260W *: The used power unit must be capable to deliver the peak output power for at least 10 ms without a decrease in the output voltage. In case of doubt this power must be considered as the nominal power.

56 3BDD010421R0101


3BDD010421R0101 57

S900 I/O System, type N

Mode Number of S900 I/O Systems

* Minimum peak output power

Nominal power

1 >210 W >80W 2 >275W >155W 3 >340W >230W 4 >405W >305W

Redundancy mode

5 >470W >380W

1 >70W >70W 2 >135W >135W 3 >200W >200W 4 >265W >265W

Single mode

5 >330W >330W *: The used power unit must be capable to deliver the peak output power for at least 10 ms without a decrease in the output voltage. In case of doubt this power must be considered as the nominal power.

The power specified in the table above must be available across the power terminals of the S900 I/O System, independent of the power cable length. With the above-specified power the voltage must not be inferior to the minimum supply voltage of the S900 I/O System (see data sheet SA910S/N). If required, the output voltage of the used power unit must be increased by adjustment. The series resistance of the power feed equipment (cables, fuses, switches) must be considered for this (see next section in this manual).

In redundancy mode, the specified power must be available for each of the two power units of the S900 I/O System.

We recommend to use the appropriate power unit from ABB, ordering code V17212-130 (adjustable to up to 28VDC) with 24VDC/10A/240W output.

Fuse protection Each power supply line should be protected separately (fuses F3 and F4 in the illustration above). Use slow-blow fuses with a minimum nominal value of 4A. The maximum value for fuse protection of the power supply to the S900 I/O System is 10A. The fuse can be provided either in the hazardous or in the non-hazardous area.


Cable CSA and length The CSA and length of the used cables depends on the respective instrumentation and can be determined by using the specifications above. –The following cross-sectional areas are recommended under the proviso that the individual S900 I/O Systems are connected to the external power supply in a star-type topology and that the power supply is set in such a way that a voltage of at least 24VDC is available across the power terminals under normal operating conditions.

• For cables up to 50 m 2.5mm²

• For cables of 50m…100m 4mm² *

• For cables of 100m…200m 10mm² * *: For cables with this cross-sectional area an additional terminal level must be inserted before the S900 I/O System, or cable pins have to be used, since usually only CSAs up to 2.5mm² are supported.

Signal circuits

Terminals

Markings/designations 16 terminals are assigned to every module slot of the S900 I/O System.

Terminals with either blue (system type S) or black (system type N) markings are used for the S900 I/O System termination unit.

14

24

34

44

13

23

33

43

12

22

32

42

11

21

31

41

The terminals are labeled as seen in the illustration.

The terminal assignment depends on the used I/O module. Refer to the data sheets or rating plates on the modules for the respective terminal assignment of a module.

58 3BDD010421R0101


Cable CSA The terminals are designed for the following cable CSAs:

Table 8-2 Cable CSAs that can be connected to the signal terminals

Wire type Cross-sectional area Rigid 0.5 – 2.5 mm²

Flexible 0.5 – 2.5 mm² Flexible with end ferrules 0.5 – 1.5 mm²

Connecting/disconnecting terminals

Cage-mounted spring terminals are used. The illustration shows the opening through which the clamping mechanism of the terminal can be opened/closed, and the opening where the wire is inserted. It is recommended to use a screw driver with a 0.6 x 3.5 mm blade in accordance with ISO 2380 / DIN 5264 for this.

Open/close clampingmechanism

Insert wire

Installation With an S900 I/O System type S the field current connections must meet the requirements of protection type "i”. The requirements defined in IEC/EN60079-14, especially Section 12 (additional requirements for type of protection "i" – Intrinsic safety) must be met. Intrinsically safe and standard signal circuits must not be connected to the same termination unit. Use different termination units to ensure proper separation.

A separate shield bar or cable gland is to be provided for connecting the cable shields of signal lines (also refer to section Field housing and section Shielding and equipotential bonding ).

3BDD010421R0101 59


Fieldbus connection

Connecting the fieldbus to the termination unit A SUB-D socket is used to connect the fieldbus to the termination unit of the S900 I/O System. For systems with redundancy capability two connectors are provided.

Figure 8-4 Connecting the fieldbus to the termination unit (second connector only for redundant systems).

Pin assignment of the fieldbus connector

Table 8-3 Pin assignment of the 9-pin D-SUB socket

Pin number

Signal Description

1 Shield Cable shield 2 3 RxD/TxD-P Receive/transmit data, positive, line B 4 5 DGND Bus termination, negative 6 VP Bus termination, positive 7 8 RxD/TxD-N Receive/transmit data, negative, line A 9

60 3BDD010421R0101


Installation With an S900 I/O System type S the fieldbus connections on the termination unit must meet the requirements of protection type "i”. The requirements defined in IEC/EN60079-14, especially Section 12 (additional requirements for type of protection "i" – Intrinsic safety) must be met. Also observe the specifications in section Fieldbus of this manual.

Fieldbus connector Follow the instructions below to connect the fieldbus:

•

•

•

•

Connect the fieldbus cable to the fieldbus connector as specified in the instruction leaflet delivered with the connector.

Plug the bus connector onto the appropriate D-SUB connector on the termination unit.

Fasten the bus connector with the respective screws.

If the bus connector is located at the start or end of a bus segment, activate the terminating resistor (switch position "ON").

Make sure that the bus stations where the terminating resistors are activated are always under power when the system is starting up or is running.

Different connector types have to be used, depending on the S900 I/O system type. Observe the specifications in section Fieldbus.

Unused bus connectors If a bus connector is disconnected, it must be protected from getting into to contact with other current circuits or with the equipotential bonding conductor. Either a mechanical fixation or an insulation can be used for this purpose.

Marking the fieldbus cables The following table shows the fieldbus markings. The two lines of a PROFIBUS DP are used as an example. The markings may be different for other devices.

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62 3BDD010421R0101

Table 8-4 Fieldbus cable markings

Cable Color Marking 1 Marking 2 Marking 3 Receive/transmit data, positive

Red Line B P +

Receive/transmit data, negative

Green Line A N -

Field housing S900 I/O Systems used in hazardous areas or in a rugged industrial environment must be protected by field housings. The appropriate empty housings or complete, approved field housings with the S900 I/O System already installed are available from ABB.

Using the empty housing FHxxx Various empty housings are listed in the data sheet for the S900 I/O System (see Applicable reference documents). These housings are approved for use in hazardous areas and have a certificate of conformity or EC Type Examination Certificate. The applicable instructions and directives for using these housings are given in the following section.

Selection The following facts are important for the selection of a field housing.

• Housing size: The housing must be dimensioned in dependence of the estimated power dissipation of the S900 I/O System and possible additional components (also refer to Power details of the field housings ).

• Configuration: The housings are available with different cable entry types. This fact has to be considered when selecting the appropriate housing.

• Material: Stainless steel 1.4301


3BDD010421R0101 63

Installing the S900 I/O System in the housing Install the S900 I/O system in the intended position in the empty field housing. Do not install it in another position. Otherwise, proper heat dissipation is no longer ensured. Fasten the system by using four stainless steel screws (M6) and spring washers. Note that the equipotential bonding between the S900 I/O System and the field housing is established at the same time. Observe the determined power limits when selecting the S900 I/O System modules to be installed on the same termination unit.

Additional components Additional components (e.g. FO converters, terminals, switches, overvoltage protectors, etc.) may be installed in the field housing in the respective positions. Observe the maximum permissible power dissipation in the field housing. Make sure that the total power dissipation of all additional components and the S900 I/O System does not exceed the limit values specified in section Power details of the field housings . If the equipment is to be used in hazardous areas, make sure to use components that are designed for the application and meet the respective requirements. Observe the specifications regarding the ambient conditions, and the instructions in the operating manuals and the EC Type Examination Certificate of the components.

Wiring The internal wiring inside the field housing must be in accordance with the applicable national standards, and with EN50019, EN50020 and IEC/EN60079-14 when the equipment is used in hazardous areas. Observe the instructions in the operating manuals of the individual components for the connection of the cables/wires. Do not lay intrinsically safe current circuits together with current circuits that are not intrinsically safe. Preferably use cable ducts.

Intrinsically safe current circuits of equipment used in hazardous areas must be marked accordingly. When using a color code, it is recommended to use blue color to identify intrinsically safe circuits. Current circuits that are not intrinsically safe must be protected with an IP30 (minimum requirement) cover according to IEC/EN60529 and have to be provided with the appropriate warning.


64 3BDD010421R0101

Connecting the power and signal lines Follow the instructions in section Mounting and connecting the system. Insert all cables through the respective cable glands and strip off the cable sheath along the specified length. Connect the cables/wires according to the terminal assignment. Make sure that the diameter of the used cables does not exceed the permissible cable diameters of the cable glands. After the installation is finished, the cable glands have to be tightened thoroughly and checked for proper fitting of the cable. Unused cable glands must be closed with the certified plugs with type of protection "increased safety".

Connect the cable shields and integrate the field housing in the equipotential bonding system as described in section Shielding and equipotential bonding of this manual.

Observe the electrical specifications and the connection instructions given in the operating manuals of the devices and components. Additionally observe the applicable national standards and section Safety and precautions of this manual.

Cable strain relief The appropriate strain relief equipment must be provided under the housings for all cables connected.

Mounting the field housing The housings are delivered with mounting brackets. Use the appropriate screws to fasten the housings to the mounting rack or wall. Select the appropriate screws and, if necessary, wall plugs in dependence of the housing weight.

The mounting bracket is designed in such a way that a spacing between the housing back and the wall is given. Use additional spacers to increase this air gap to at least 25 mm. Always keep this air gap on the housing back free from any objects like covers or other material to ensure proper ventilation. Make sure that air can pass freely. If possible, the housing should be mounted to a freely positioned rack instead of the wall, where free air circulation on the back side is possible. Observe the specified mounting orientation (S900 mounted horizontally, cables entered from the bottom side).


When selecting the installation site observe the specified Environmental capabilities. See to it that the necessary spacing from heat sources is observed and direct exposure to sun light is avoided. Otherwise the ambient temperature might exceed the permissible range. If necessary, re-arrange the equipment. Use sun shields to prevent direct exposure to sunlight. When designing/installing sun shields observe the different angles of incidence in dependence of the season. Avoid heat accumulation under the sun shields.

Additionally, it is recommended to protect the equipment against weather impact.

Cleaning after mounting Upon mounting and prior to commissioning the electrical equipment has to be cleaned. Remove dust accumulation, cable pieces, insulating material, and mounting material like screws, connectors, tie wraps, etc, that is not needed. Remove all objects that may obstruct air vents. Check to see that the inlet of the air conditioning system is clean. Clean if required.

Verification and approval The field housing and the installed components must be submitted to a verification and approval. Only if the equipment passes this acceptance test it may be used in hazardous areas. The test can be performed separately by an expert in accordance with ElexV (regulation for electrical plants in hazardous areas) or during the final acceptance test of the entire plant.

Upon installation and mounting, field housings must be submitted to the relevant acceptance test for equipment to be used in hazardous areas.

As a rule, the following checks are performed on ABB installations and documented in individual test reports.

• Check if all used components are suitable for the intended application (marking of electrical equipment).

• Check if all instructions in the operating manuals and EC Type Examination Certificates of the components have been observed.

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66 3BDD010421R0101

• Check if the Power details for the S900 I/O system and the Power details of the field housings have been considered and the specified limits have been observed.

• Check if the installation complies with the regulations of EN 50014, EN50019, EN50020, IEC/EN60079-14 and the instructions in this manual.

• Check for complete and correct documentation (wiring diagrams, assembly drawings, operating instructions for the components, EC Type Examination Certificates, certificates of conformity for all components).

Maintenance and dismounting The housing may be opened for operation and maintenance during operation, even in the hazardous area.

The S900 I/O System components (I/O modules, Communication Interfaces, power units) may be removed/plugged in during operation under the proviso that the instructions in section Components assembly and commissioning are observed.

Do not open current circuits that are not intrinsically safe while the system is running. Do not remove the cover and warning on the respective terminals, components and cables when the system is energized. When disconnecting fieldbus links, be sure to consider all possible effects an other devices connected to the fieldbus.

The field housing may only be dismounted when the power supply is switched off and when no field signals are applied or when the plant is in a safe mode.

Using cabinets The appropriate, completely installed cabinets i.e. field housings with already installed and wired components are available from ABB. The operating instructions and documentation of these cabinets must be observed.


9. Components assembly and commissioning

This section describes the assembly and initial start of the S900 I/O System components. For details about connecting the system to an open control system and commissioning please refer to section Applicable reference documents.

Selecting and combining components When selecting the components pay special attention to the type and the intended use (see S900 System installation sites). For every type S component there is a corresponding component of type N which has exactly the same functionality. On the contrary, some components of type N do not have an equivalent of type S. Refer to the data sheets for details.

Do not mix components of different types. All components (termination unit, power units, Communication Interfaces and I/O modules) must be of the same type (either N or S).

Notes on explosion protection Every S900 I/O System module and termination unit has a separate EC Type Examination Certificate. The certificates are matched with each other. It is not necessary to deliver a special "Proof of intrinsic safety" for the internal connections between the individual modules and the termination units, since this has already bee evaluated by the verifying authorities and documented in the respective EC Type Examination Certificates under item 15. The individual internal current circuits are evaluated in the EC Type Examination Certificate PTB 00 ATEX 2156U for the termination units. As a result, all S900 I/O System components can be used together without requiring further evaluations or tests on the customer side.

3BDD010421R0101 67


Power units

Power units of type S Power units of type S (e.g. SA910S) have an automatic locking mechanism to ensure explosion protection. The power unit is only switched on when all four fastening screws are fixed. These locking screws must be fastened carefully and evenly.

The following procedure/step sequence must be observed when commissioning or replacing a power unit:

Table 9-1 Commissioning/replacement procedure of type S power units

Action Procedure 1. Connect the power lines to the termination

unit. 2. Plug the power units onto the termination unit. 3. Switch on the power.

Commissioning the power unit

4. Fasten the screws, the power unit is switched on automatically.

1. Undo the fastening screws. 2. Remove the power unit. 3. Plug in the new power unit.

Replacing a power unit

4. Fasten the screws, the power unit is switched on automatically.

Observe the specified procedure when commissioning the power unit. Do not connect or disconnect live power cables when the power unit is plugged in. Exclusively switch on or off the power units by using a bounce-free switch or the fastening screws.

The replacement procedure specified above also has to be observed to ensure proper redundancy operation.

When using a power unit which does not have the front panel label "prellfrei schalten / bounce-free switch"

the commissioning and replacement instructions in the leaflet delivered with the unit have to be observed, to ensure proper redundancy operation.

68 3BDD010421R0101


Power units of type N Power units of type N do not have an automatic locking mechanism. Nevertheless, the four screws must be fastened to ensure proper operation. The following procedure must be observed when commissioning or replacing a type N power unit:

Table 9-2 Commissioning/replacement procedure of type N power units

Action Procedure 1. Connect the power lines to the termination

unit. 2. Plug the power units onto the termination unit.

Commissioning the power unit

3. Switch on the power.

1. Switch off the power. 2. Remove the power unit. 3. Plug in the new power unit.

Replacing a power unit

4. Switch on the power.

Observe the specified procedure when commissioning the power unit. Do not connect or disconnect live power cables when the power unit is plugged in. Exclusively switch on or off the power units by using a bounce-free switch or the fastening screws.

The replacement procedure specified above also has to be observed to ensure proper redundancy operation.

When using a power unit which does not have the front panel label "prellfrei schalten / bounce-free switch"

the commissioning and replacement instructions in the leaflet delivered with the unit have to be observed, to ensure proper redundancy operation.

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70 3BDD010421R0101

Modules

Selecting the modules Observe the technical specifications in the applicable data sheets for the selection of the modules. When using modules of type S, observe the regulations in IEC/EN60079-14, especially section 12 (additional requirements for the type of protection "I” – Intrinsic safety).

Replacing a module The S900 I/O System termination units are designed for accommodating 4, 8 or 16 I/O modules. The modules can be removed and plugged in while the system is running. It must, however, be taken into account that the affected channels generate a diagnostic message in the open control system, that the input data are set according to the parameterized substitution value strategy, and that, in case of an output module, the field devices can no longer be triggered. Prior to removing or plugging in a module, the user must make sure that no dangerous or unexpected conditions or states of the plant may occur.

Field circuits A module should only be replaced with another module of the same type (check catalog number). When using a different module type, the interconnection with the field device must be checked and evaluated again. This is especially important for modules of type S. In this case, the intrinsically safe interconnection needs to be examined carefully.

Number of modules The maximum number of modules that can be plugged onto a termination unit is limited by the maximum power output of the power units and by the maximum permissible power dissipation which depends on the installation conditions. Observe the specifications in section Power details.


3BDD010421R0101 71

Slot Exclusively plug the modules into the dedicated module slots. Plugging a module into a Communication Interface slot is not permitted and may damage the module and/or termination unit.

Special attention has to be paid when connecting/disconnecting feeding input modules (DX910, AI910, AI930). If they are plugged in the wrong slot, they may cause unwanted switching actions of the connected actors.

Communication Interface The appropriate Communication Interface has to be selected according to the used S900 I/O system type (S or N). The Communication Interface can also be removed/plugged in while the system is running. The following instructions have to be observed.

Single mode (no redundancy) In single mode fieldbus communication is no longer possible once the Communication Interface has been removed. The output modules follow the substitution value strategy defined before.

Redundancy mode In redundancy mode (i.e. two Communication Interfaces and two fieldbus links are used, redundancy toggle from the open control system is possible) one of the Communication Interfaces can be replaced without affecting the signals. Only a diagnostic message related to the missing Communication Interface is generated.

Slot Exclusively plug the Communication Interfaces into the dedicated Communication Interface slots. Plugging a Communication Interface into an I/O module slot is not permitted and may damage the Communication Interface and/or termination unit.


72 3BDD010421R0101

Setting the address Refer to the manual for the CI920 Communication Interface of the S900 I/O System (see Applicable reference documents).

Unlocking and encoding

Unlocking the modules and the Communication Interfaces The modules are fastened on the termination unit be simply plugging them in the dedicated slots. When plugging in a module, make sure that the brackets of the termination unit slide into the respective guides on the module top and bottom side. Push in the modules until the brackets snap in (audibly and visibly) at the top and bottom side of the module.

To undo this lock, slightly lift off the brackets at the top and bottom side of the module and pull out the module. Pull out the module evenly and straight.

Encoding the housings The I/O module and Communication Interface housings are provided with an optionally usable mechanical encoder. It can be used to identify the units clearly and avoid that they are inadvertently plugged in a wrong slot.

The coding pins must be inserted on the module back and in the slots of the termination unit (see the illustration below). They can be turned and set to 6 positions, each. The positions of the upper and lower coding pins on a module should be identical. As a result, there are six possible codes (see illustration).


3BDD010421R0101 73

Coding position 1 Coding position 2






Figure 9-1 Encoding the module housing

The following table provides some suggestions for encoding the individual module types

Table 9-3 Module type codes

Module type Coding position Communication Interface Coding position 1 Analog input module AI…. Coding position 2 Analog output module AO… Coding position 3 Digital input module DIO…/FI… Coding position 4 Digital output module DO… Coding position 5 Temperature module TI… Coding position 6


Using hand-held terminals (HART) The S900 I/O system permits to run a hand-held terminal (HHT) or another HART operating terminal in parallel. The HART terminal can be directly connected in parallel with the signal circuits. There is no need to connect an extra resistance into the circuit. The following modules support the connection of a HART terminal:

• AI910/930/931 type S and N

• AO910/920/930 type S and N

When using the HART terminal together with S-type modules (intrinsically safe circuits), make sure that the intrinsic safety of the circuit is maintained when circuits are interconnected. The Ex-specifications of the HART terminal must be considered.

When using HART terminals together with an S900 I/O System type S, observe the standards and regulations pertaining to the interconnection of intrinsically safe current circuits (see EN50039).

74 3BDD010421R0101


Figure 9-2 Connecting a HART terminal

When parameterizing and configuring field devices with the HART terminal, make sure that no unintended or dangerous conditions or states of the plant may occur.

Using a HART terminal may cause dangerous inconsistencies between the database of the open control system and the field device's parameter data set.

It is therefore recommended to use the HART terminals for local monitoring, only, or to avoid using them. The S900 I/O System permits to access all HART data via the central Engineering Tool. This way is much easier and more convenient. The risk of data inconsistencies implied by HART terminals is reliably avoided by using the Engineering Tool.

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10. Shielding and equipotential bonding

Introduction The S900 I/O System S900 meets the EMC protection requirements for industrial areas. Compliance with the respective directives is documented by the CE mark in accordance with EC Directive 89/336/EC . Additionally, the S900 I/O System meets the requirements of the NAMUR recommendation NE 21.

The ensure compliance with to the above-mentioned EMC requirements, the following installation and commissioning instructions must be observed for the entire automation system (open control system, S900 I/O System, field devices, grounding, shielding, cabling and connecting equipment). When using the equipment in hazardous areas, observe the instructions in the respective section of the regulation IEC/EN60079-14: "Electrical Installations in Hazardous Areas".

Basic requirements • Exclusively use devices with CE mark according to EC Directive

89/336/EC.

• Ground cable shields in a sufficiently large area. Use shield clamps or cable glands with shield rest.

• Establish a connection to an equipotential bonding system

• When connecting the cable shields, establish a low-impedance connection, to reduce the effect of high interference frequencies. This also applies to the grounding connection of the device. Usually, connections via long conductors (e.g. grounding conductors, functional grounding conductors, equipotential bonding conductors) do not meet these requirements.


Overview The illustration below shows a schematic diagram of the equipotential bonding.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 1

98 7 654

321098 7 654

32100 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 1

98 7 654

321098 7 654

32100 1

24 V DC

12

3

4

567

PRO

FIBU

S D

P

Zone 1/2Non-hazardous area

8

35

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 1

98 7 654

321098 7 654

32100 1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 1

98 7 654

321098 7 654

32100 1

24 V DC

12

3

4

567

PRO

FIBU

S D

P

Zone 1/2Non-hazardous area

8

35

Figure 10-1 Equipotential bonding

3BDD010421R0101 77


78 3BDD010421R0101

Explanation:

1. Connection to functional ground/protective ground at a central point of the switch room

2. Equipotential bonding system within the plant, including all metal parts 3. Connection of the signal cable shields to the field housing via shield cable

glands. Alternatively, a shield bar connected to the field housing can be used.

4. No connection of the signal cable shield on he field device side. 5. Connection of the fieldbus cable shield to the shield bar or cable entry

through shield cable gland Connection of the cable shield to the shield clamp integrated in the fieldbus connector.

6. Connection of the field housings to the equipotential bonding system 7. Connection of the equipotential bonding system of the plant to the

functional ground/protective ground in the switch room (optional). 8. Direct connection of the functional ground/ shielding for the S900 power

units to the central power supply.

Termination unit Use a cable with the same cross-sectional area (at least 4 mm²) to connect the S900 I/O System termination unit to the equipotential bonding system. If field housings are used, there is already a fixed electrical connection between the termination unit and the field housing. With this, the field housing becomes a part of the equipotential bonding system and must be connected to it with the same cross-sectional area. If non-conducting field housings are used, the S900 termination unit must be directly connected to the equipotential bonding system.

Power supply The power connector of the S900 termination unit is provided with a clamp for the connection of functional ground. Preferably, the functional ground is derived from the central power supply and then brought to the S900 I/O System as a PE wire (marked green/yellow) in the supply line. No functional grounding is required for the 24 V version of the S900 power unit. When using the equipment in hazardous areas, make sure that the functional ground conductors are laid and connected in accordance with the requirements of protection type "Increased Safety EExe".


3BDD010421R0101 79

Fieldbus In order to ensure optimal shielding and grounding, the S900 I/O Systems and the fieldbus cable shields must be connected to the equipotential bonding system several times. This method yields optimal results regarding the electromagnetic compatibility and may be used without any limitations in hazardous areas to IEC/EN60079-14 Section 12.2.2.3 in plants with "a high degree of guaranteed" equipotential bonding in the entire installation. It should be taken into account that an equipotential bonding system is mandatory in hazardous areas to comply with IEC/EN60079-14, Section 6.3. In addition to the measures specified in this standard (e.g. integration of protective ground conductors, protective tubes, metal cable shields, cable armors and metal parts in the equipotential bonding system) the following measures can be used:

• Laying fieldbus cables on metal platforms

• Integrating the cable platforms in the equipotential bonding system

• Establishing safe, current-carrying, low-impedance (seen under high-frequency aspects) connections between the cable platforms and between cable platforms and metal parts.

However, it must be ensured that the compensating currents do not damage the fieldbus cable and, when used in hazardous areas, do not cause igniting sparks. Refer to IEC60079-14 for details.

The fieldbus cable shields are connected to a shield bar linked with the equipotential bonding system. Make sure that the shield is not interrupted and is directly connected to the shield clamp integrated in the fieldbus connector (see also section Fieldbus connector).


In order to avoid that impermissible energy potentials are transferred into the hazardous area, either the equipotential bonding conductor must be continued until reaching the start of the fieldbus segment in the non-hazardous area (see the illustration above), or the cable shield must be connected "safely" (see illustration below) at all transition points between the safe and the hazardous area. "Safe" means that all wires of the cable shield are twisted and protected from being fanned out by an end ferrule and are then connected to the respective screw terminal. The cable shield connections within the hazardous area are not relevant for safety issues. These connections ca be established by using standard shield clamps (bow contacts).

S900 I/O System

S900 I/O System

S900 I/O System

Equipotential bonding


Open control system / master

Non-hazardous area Hazardous area

Functional/protective ground

S900 I/O System

S900 I/O System

S900 I/O System



Open control system / master



Figure 10-2 Equipotential bonding of the fieldbus, detailed illustration

80 3BDD010421R0101


S900 I/O System

S900 I/O System

S900 I/O System



Open control system / Master



S900 I/O System

S900 I/O System

S900 I/O System



Open control system / Master



Figure 10-3 Equipotential bonding at the transition point to the hazardous area

Signal circuits The S900 I/O System meet the requirements of the EC Directive 89/336/EC (CE marking) and of the NAMUR recommendation NE21 even without using shielded signal cables for connection to the field devices. This is sufficient for typical industrial environments where only devices that meet the above-stated directives are installed. If higher requirements regarding EMI/RFI shielding have to be met, it is recommended to use shielded signal cables and to connect the cable shield on one side to the shield bar integrated in the termination unit or provided separately in the field housing. The shield bar must be connected to the equipotential bonding system. If a metal field housing connected to the equipotential bonding system is used, the signal cable shield can also be connected by using the appropriate cable glands.

How the shields are connected to the field device depends on the field device requirements and the plant design. If the shields need to be connected on both sides, it is important to ensure proper equipotential bonding in hazardous areas. It is not permissible to directly connect the cable shield on both sides in a hazardous area if sufficient equipotential bonding is not ensured. In these cases capacitive connection of the shield is a possible solution for increasing the electromagnetic compatibility.

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Field housing If a metal field housing is used, it has to be integrated in the equipotential bonding system. If nonmetallic housings are used, the built-in components (termination unit, shield bars, etc.) must be connected separately to the equipotential bonding system.

Cable and wire layout

General Although current circuits laid in parallel in the same metal transmission line may be independent of each other, there is nevertheless a capacitive and/or inductive coupling between them, due to the line geometry and the material properties. The intensity of this coupling and, thus, the intensity of possible interference depends on the spacing between and the overall length of the conductors laid together. As a rule, it is recommended to lay signal lines not too close to power lines. In order to avoid unwanted effects, it is useful to plan the cable layout in dependence of the electrical properties and the current circuits to be connected. The cables/lines of current circuits with similar operating levels, terminating impedance and interference properties should be grouped in tightly packed cable bunches. These cable bunches should be laid with a spacing of approximately 20 cm. Usually, the interference between them is already sufficiently low with this spacing. According to EC/EN60079-14 intrinsically safe and not intrinsically safe circuits may be realized in the same cable bunch if the cables are protected by grounded shields that are separated from each other or if the cable insulation of the intrinsically safe circuits meet special requirements.

Power cables Inside and outside the cabinets and racks the power cables must always be laid separately from other metal transmission lines. The local standards and regulations for the installation must be observed. For power cables laid in hazardous areas the requirements defined in IEC/EN60079-14:, Section 11 (Additional requirements for the type of protection "e” – Increased safety) must be observed additionally.


3BDD010421R0101 83

Field signal lines It is recommended to consider the following criteria for the field signal line layout:

The following current circuit should not be realized in the same cable trunks:

• Input circuits and output circuits

• Analog/digital circuits with static switches and digital circuits with mechanical contacts.

• Circuits with type of protection "Intrinsic safety" and circuits that are not intrinsically safe.

Note that the feed and return lines of the current circuits should always be laid in the same cables. The wire pairs should be twisted, to reduce the surface of the circuit loops.

Additionally, the electrical specifications and connecting instructions given in the manuals of the respective devices and the applicable national standards and regulations must be observed.

FO cables To avoid mechanical damage, FO cables must always be laid separately from other, metal-type transmission cables. Due to the different physical transmission method and interference properties no minimum spacing has to be observed. It must, however, be noticed that FO cables are only flexible to a certain extent. They may be bent slightly, but not kinked. The bending radius specified by the FO cable vendor must be observed. A protecting tube must be used to protect underground FO cables from decay and mechanical damage.

Lightning and overvoltage protection In accordance with IEC61312 lightning protectors are further subdivided in:

External lightning protectors e.g. capturing equipment and lightning arresters in the open-air area and the corresponding grounding equipment


Internal lightning protectors e.g. potential equalizers and charge eliminators, building shields

Overvoltage protection e.g. room shields, cable shields, and overvoltage arresters

External and internal lightning protectors are part of the buildings at the customer site and are, therefore, not included in the ABB product range. The measures listed below, however, assume that the appropriate internal and external lightning protection equipment is present and functioning.

Protection through shield grounding It is possible to reduce transient overvoltage by limiting the cable length that might be affected by partial lightning current. The cable shield should be connected on both sides - and possible directly at the transition points between protected and unprotected areas or directly at the sensors and actors in the unprotected area - to the equipotential bonding system. The distance between the two grounding points defines the influenced line length.

Overvoltage protection equipment Generally, overvoltage protectors must be inserted in the line between the unprotected areas and the components to be protected. To ensure proper protection of the S900 I/O System components, the overvoltage protectors should be placed at the point where the cable enters the building. If the sensors or actors in the field are to be protected as well, additional overvoltage protectors are required. These should be installed close to the actors/sensors.

The following overvoltage protection equipment can be used together with the S900 I/O System .

84 3BDD010421R0101


3BDD010421R0101 85

Table 10-1Overvoltage protectors

S900 I/O System, type N Protection of… Overvoltage protector Catalog number * Communication Interface CI920N PROFIBUS-DP, standard version

• Basic part BAS • Lightning ductor CT Type MD

HF 5 • Shield fastener for bus cable

EFK BCT

919 506 919 570 919 508

All I/O module signal circuits

• Basic part BAS • Lightning ductor CT Type MD

30

919 506 919 544

S900 I/O System, type S

Protection of… Overvoltage protector Catalog number * Communication Interface CI920S PROFIBUS-DP, intrinsically safe

• Basic part BAS EX • Lightning ductor CT Type MD

HFD 6 • Shield fastener for bus cable

EFK BCT

919 507 919 583 919 508

All I/O module signal circuits intrinsically safe

• Basic part BAS EX • Lightning ductor CT Type MD

EX 30

919 507 919 581

* These components are available from :

DEHN + SÖHNE GmbH & Co. KG

Elektrotechnische Fabrik

Hans-Dehn-Strasse 1

D-92306 Neumarkt http://www.dehn.de

Additional information All connections to the equipotential bonding system should be made by using the shortest path and with a big contact surface. Metal cable clamps which concentrically press the shield onto the (grounded) surfaces are suitable.

All lightning and overvoltage protection measures must be in accordance with IEC/EN60079-14.

http://www.dehn.de/


86 3BDD010421R0101

11. Maintenance, repair, trouble-shooting

Maintenance All S900 I/O System components are virtually maintenance-free. Maintenance and repair are therefore reduced to periodic checks for damage and the replacement of individual modules.

Devices and components that are defective or suspect to be defective must not be used any longer.

Do not use intrinsically safe components in intrinsically safe current circuits once they have been connected to a circuit that is not intrinsically safe.

The operator of electrical equipment that is used in hazardous areas is obliged to commission a qualified electrician to inspect and examine the equipment at defined intervals for a proper condition, e.g. to check the housings for cracks or other damage, the gaskets for leakage or damage, and the terminals and plugs to see if they are seated properly.

When replacing the S900 I/O System components, observe the instructions in section Components assembly and commissioning.

Prior to replacing or dismounting parts that cannot be plugged in / removed under power disconnect the respective equipment from power. Use ABB genuine spare parts, only.

Trouble-shooting Under the proviso that the S900 I/O System modules are used as intended and according to the instructions in this manual, the only trouble-shooting actions that may be required are checks for fieldbus and signal transmission errors (wire break, etc.). The S900 I/O System is provided with indicator lamps (LEDs) which allow for quick error localization and debugging.

A distinction is made between power supply errors, module errors, communication errors, parameterization errors, and channel errors.


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All errors indicated locally by the LEDs are also reported by a PROFIBUS diagnostic message.

Additionally, the S900 I/O System is provided with a simulation (forcing) option allowing to perform important service and commissioning tasks. The simulation function serves for

• testing the applications in the PLC or OCS • simulating the outputs and testing the actors e.g. for checking how the

system responds to the violation of limit values, without actually affecting the control loop

• avoiding unwanted error messages in the case of signal failures that may occur when a defective module is replaced.

For details about diagnostics and forcing refer to the Communication Interface manual (see Applicable reference documents).

Repairing Ex-devices If a part of the S900 I/O System that is relevant for explosion protection is repaired, it may only be put back into service after being checked by an expert for fulfillment of the explosion protection requirements. The expert has to confirm that the part has passed the acceptance test by issuing a certificate or attaching a test badge to the electrical equipment. This check is not required if the electrical equipment is submitted to a routine check test by the manufacturer before being put into operation again, and if the respective test badge is attached to the equipment, indicating that the routine check test has been passed successfully.


88 3BDD010421R0101

12. List of tables, list of figures

List of tables Table 2-1 Applicable reference documents 10 Table 6-1 Bus line parameters 26 Table 6-2 Line lengths per segment 26 Table 6-3 Line lengths per segment 30 Table 6-4 Characteristics of fiber-optic lines for PROFIBUS 34 Table 7-1 Power details of Ex modules 46 Table 7-2 Power details of non-Ex modules 48 Table 7-3 Maximum permissible power dissipation in the field housing 50 Table 8-1 Properties of the connectable power wires 54 Table 8-2 Cable CSAs that can be connected to the signal terminals 59 Table 8-3 Pin assignment of the 9-pin D-SUB socket 60 Table 8-4 Fieldbus cable markings 62 Table 9-1 Commissioning/replacement procedure of type S power units 68 Table 9-2 Commissioning/replacement procedure of type N power units 69 Table 9-3 Module type codes 73 Table 10-1Overvoltage protectors 85

List of figures Figure 4-1 S900 I/O System 13 Figure 5-1 Classification of hazardous areas, example 17 Figure 5-2 Installing the S900 I/O System in a non-hazardous area 19 Figure 5-3 Installing the S900 I/O System in a hazardous area, zone 2 21 Figure 5-4 Installing the S900 I/O System in a hazardous area, zone 1 23 Figure 6-1 Type N fieldbus topology 25 Figure 6-2 Figure 6-2 Type S fieldbus topology 28 Figure 6-3 Interconnection of the intrinsically safe fieldbus 31 Figure 6-4 Fieldbus system with optical stub connection 35 Figure 6-5 Fieldbus system with an optical network 36 Figure 6-6 Fieldbus system with an optical ring 37 Figure 6-7 Examples for redundant configuration of a fieldbus system 39 Figure 8-1 Overview of the termination unit connection levels 53


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Figure 8-2 Power terminals on a termination unit with redundancy capability 54

Figure 8-3 S900 I/O System power distribution 55 Figure 8-4 Connecting the fieldbus to the termination unit 60 Figure 9-1 Encoding the module housing 73 Figure 9-2 Connecting a HART terminal 76 Figure 10-1 Equipotential bonding 77 Figure 10-2 Equipotential bonding of the fieldbus, detailed illustration 80 Figure 10-3 Equipotential bonding at the transition point to the hazardous

area 81


90 3BDD010421R0101

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