fieldbus 1 accessing all areas. fieldbus 2 scope of presentation safe area applications non-arcing...
TRANSCRIPT
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Fieldbus
Accessing all Areas
2
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us Scope of presentation
Safe Area Applications
Non-Arcing Systems
Non-Incendive Systems
Intrinsic Safety Systems
FISCO
FNICO
Zone 2
Zone 2
Zone 2,1,0
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18-30 voltPower
Generalised Fieldbus connectionGeneralised Fieldbus connection
Non-hazardous area
TT FieldbusHost
Hub
General fieldbus application in safe area terminated at both ends of bus
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Hazardous area Non-hazardous area
TT FieldbusHostT T
Non-hazardous area
TT FieldbusHost
18-30 voltPower
Generalised Fieldbus connectionGeneralised Fieldbus connection
Hub
Need for hazardous area protection suitable certified interface applied
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For general purpose applications in
31.25 kbit/s fieldbus systems terminate at both ends of fieldbus switched internal terminator option
Isolated power conditioning 19V, 350mA output
Suitable for Safe Area &
Hazardous Area applications Certified for installation in Zone 2
hazardous areas Needs suitable certified interface
eg, MTL791, for intrinsically safe
field connection
MTL5995 Power SupplyMTL5995 Power Supply
ATEX II 3 GEEx n A IIC T4
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us Redundant Fieldbus Power SystemRedundant Fieldbus Power System
Backplane connects to : bus terminator input power supplies host system fieldbus trunk alarm circuitry
Load sharing by redundant supplies
Up to 8 units may be daisy-chained
with common alarm carrier jumper supplied
version without segmentterminator available
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T
FieldbusHost
Fieldbus
SystemAlarm
Supply‘A’
18-30 voltPower
Supply‘B’
Power Conditioning high impedance to fieldbus network
Redundant DC Power Inputs Power Isolation to fieldbus
250 V ac galvanic isolation Redundant Output Power 25 Volt, 350mA output per module LED indicates bus is powered Hot-swappable
modules & / or input supply can be
replaced without affecting fieldbusoperation
Alarm Circuitry input power or unit failure galvanic isolation from other
functions Certification
FM Class 1 Div2 ATEX II 3 G EEx nA IIC T4
Zone 2 Mounting
Redundant Fieldbus Power SystemRedundant Fieldbus Power System
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18-30 voltPower
T
FieldbusHost
Fieldbus
SystemAlarm
Supply‘A’
Supply‘B’
T
FieldbusHost
Fieldbus
Redundant Fieldbus Power SystemRedundant Fieldbus Power System
Common connectionswithin addressing
limitations
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us Redundant Fieldbus Power SystemRedundant Fieldbus Power System
Note : the fieldbus connection is
certified as non-arcing
EEx nA IIC T4
It is NOT a FISCO / FNICO
field connection an added interface would be
necessary to achieve this end
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us MTL5053 Isolator / Power SupplyMTL5053 Isolator / Power Supply
The MTL5053 extends 31.25kbit/s fieldbus networks into hazardous areas Provides power to the highway & for communication to field devices Separate power may be required for safe-area field devices
Supply voltage 20 to 35Vdc Isolation : 250V ac between
safe area fieldbus circuits hazardous area fieldbus circuits power supply
Provides 18.4 volts at max 80 mA Safety description 22V, 102, 216mA Isolator transparent to fieldbus, hence
termination at isolator is not a pre-requisite Switchable safe area terminator
Ex II (1) GD[EEx ia] IIC
31.25kbit/s fieldbus
Safe areaHazardous area
MTL 4021
TT
MTL5053
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Safe areaZone 2 Zone 1 Zone 0
Division 2 Division 1
Some definitionsSome definitions
Safe Areasystem
NAsystem
NIsystem
Non-Arcing SystemsNon-Incendive Systems
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Resistive Curves
Current
Voltage
Hydrogen group
Ethylene group
Propane group
Methane group
Power = volts x amps
The principle oflive working
Limit the energyin the circuit
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Resistive Curves
Current
Voltage
Hydrogen group
230 mA
24 Volts
Apply aSafety Factor
Safety Factor Unity : Zone 2 1.5 : Intrinsic Safety
Fault-tolerantcomponents not
required for Zone 2
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us Types of circuit in Zone 2Types of circuit in Zone 2
NON-INCENDIVECIRCUITS :
• Unity Safety Factor• Low energy
circuits• Systems concept• Live-workable
Energy-limited
NON-ARCINGCIRCUITS :
• High energy & mainscircuits
• No systems concept
• Not live-workable
User must NOT permit arcing
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Safe area Zone 2 Zone 1 Zone 0
Unclassified location Division 2 Division 1
Complete hazardous area capabilityComplete hazardous area capability
Safe Areasystem
NAsystem
NIsystem
ISsystem
Zone 0system
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us Safe Area or Non Arcing InstallationSafe Area or Non Arcing Installation
All trunks & spurs EEx nA IIC T4 Vmax 32 V Imax 1.5 A
System Certification : Ex nA IIC T4 Class 1, Div 2, Groups A,B,C,D, T4
Terminator : FBT-1 Vmax 32 V
Installation in => IP54
‘nA’
‘nA’
Max output : 32 V 1.5 A
MTL5995 FPS-I
Live working NOT permitted in a hazardous area
FF-816 specification : 32 V 1.5 A
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us Non Incendive / ‘Spurguard’ legsNon Incendive / ‘Spurguard’ legs
Spurguard legs : EEx nL IIC T4 Vmax 32 V Imax 60 mA
System Certification : Ex nA [nL] IIC T4 Class 1, Div 2, Groups A,B,C,D, T4
Terminator : Vmax 32 V
Installation in => IP54 Live working NOT permitted
on ‘nA’ trunk
‘nA’
‘nA’
‘nL’
‘nL’
Live working safe on ‘NI’ spurs
FF-816 specification : 32 V 1.5 A
Max output : 32 V 1.5 A
MTL5995 FPS-I
Main trunks : EEx nAL IIC T4 Vmax 32 V Imax 1.5 A
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us Non Incendive SystemNon Incendive System
System Certification : Ex nL IIC T4 Class 1, Div 2, Groups A,B,C,D, T4
Terminator : Vmax 32 V
Installation in => IP54 Live working permitted
throughout
‘nL’
‘nL’
‘nL’
‘nL’
MTL9111 Max output :
14 V 233 mA
All trunks & spurs EEx nL IIC T4 Vmax 14 V Imax 233 mA
MTL9112 option for IIBwith appropriatesafety parameters
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Spurguard legs EEx nL IIC T4 Vmax 14 V Imax 60 mA
Installation in => IP54
‘nL’
‘nL’
‘nL’
Live working permitted throughout
MTL9111 Max output :
14 V 233 mA All trunks & spurs
EEx nL IIC T4 Vmax 14 V Imax 233 mA
‘nL’
Terminator : Vmax 32 V
MTL9112 option for IIBwith appropriatesafety parameters System Certification :
Ex nL IIC T4 Class 1, Div 2, Groups A,B,C,D, T4
Non Incendive >> ‘Spurguard’ legsNon Incendive >> ‘Spurguard’ legs
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us Intrinsically Safe (Non-FISCO) InstallationIntrinsically Safe (Non-FISCO) Installation
Available output : 18.4 V 80 mA
Safety parameters : 22 V 216 mA
MTL5053
System Certification : Ex ia IIC T4 Class 1, Div 1, Groups A,B,C,D, T4
Terminator : Vmax 24 V Imax 250 mA
Installation in => IP54 Live working permitted throughout
‘IS’
‘IS’
‘IS’
‘IS’
FF-816 specification : 24 V 250 mA
into Zone 0
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FISCO
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us Intrinsically Safe (FISCO) InstallationIntrinsically Safe (FISCO) Installation
MTL9121 IS : IIC 14.0 V 180 mA
MTL9122 IS : IIB 14.8 V 380 mA
Megablock rating : Vmax 14.8 V Imax 380 mA
System Certification : Ex ib IIC T4 Class 1, Div 1, Groups A,B,C,D, T4
Use in appropriate gas group
Terminator : Vmax 24 V Imax 250 mA
Installation in => IP54 Live working permitted throughout
‘IS’
‘IS’
‘IS’
‘IS’
Limited to Zone 2 & 1 All devices to be approved
for FISCO
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Network CalculationsNetwork Calculations
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Sufficient current capacity ?
HostHostMultiple power supply configurationMultiple power supply configuration
T
T
T
T
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Zone 1 / Div1Hazardous Area
Host
T
T
Host trunk24V
supply
L
N
E
2- 3+ 4- 5 S 6+
T
T
7+ 8 S 9 -Safe Area
Basic configuration9121 & 9122
Basic configuration9121 & 9122
6 devices (120 mA) in IIC13 devices (260 mA) in IIB
if 20 mA consumption each device
6 devices (120 mA) in IIC13 devices (260 mA) in IIB
if 20 mA consumption each device
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Zone 1 / Div1Hazardous Area
Host
T24Vsupply
L
N
E
2- 3+ 4- 6+
T
T
7+ 8 S 9 -Safe Area
T
The 24 volt power supply is converted to an intrinsically safe supply to feed the IS trunk
The Fieldbus signal, which is superimposed on the IS voltage, is fed via the interface device to & from the field devices
Power& data
Power& data
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T
T
T
T
HostHostMains or 24-voltpower supply
Mains or 24-voltpower supply
Power consumption9121 : 190mA9122 : 300mA
Zone2 / Div2
SafeArea
89138914
PowerUnits
5991PowerUnit
Mains
Mains
8914 : 10 A5991 : 2 A
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Model Apparatus UseableNumber Class Output
V mA9121-IS IIC 12 1209122-IS IIB 12.8 260
Design ParametersDesign Parameters
Parameter ValueLoop resistance 15 ohm to 150 ohm / kmLoop inductance 0.4 mH to 1 mH / kmCapacitance 80 nF to 200 nF / kmSpurs are in addition to permitted maximum cable length
FISCO cable parameters
System design determined from : power supply output voltage power supply available current knowledge of current consumption of each field device
survey shows a range of 10 to 28 mA 20 mA is assumed
application of Ohm’s Law to the cable network assessment for adequate voltage at each field device
Line resistance of 50 /km is assumed within the FISCO range of 15 to 150 /km
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us Typical IIC calculationTypical IIC calculation
Model9121-IS : IIC
UseableOutputV mA12 120
600 metreIS trunk
NODE
5 connectedfield devices
at end of trunk
T
eachinstrumentdraws 20 mA
Eg : I = 100 mA600 metres
30 = 3 volts 3 volts
100 mA
9 volts
12 volts
30m spur= 1.5
carrying 20 mAvolt drop= 30 mV
600 metreIS trunk
If current drawn < 20 mA
then instrument
population can be increased
HydrogenGas Group
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Model9121-IS : IIC
UseableOutputV mA12 120
250 metres
10.75 V
5 distributedfield devices
eachinstrumentdraws 20 mA
I = 100 mA12.5
= 1.25 volts
12 volts
9.75 V
9.25 V
T
250 metres
250 metres
I = 40 mA12.5
= 0.50 volts
I = 80 mA12.5
= 1.0 volt
750 metreIS trunk
Typical IIC calculationTypical IIC calculation HydrogenGas Group
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us Typical IIB calculationTypical IIB calculation
Model9122-IS : IIB
UseableOutputV mA12.8 260
NODE
12 connectedfield devices
at end of trunk
T
12instrumentseachdrawing20 mA
I = 240 mA= 3.8 volts dropthru 316 metres
of 15.8 3.8 volts240 mA
9 volts
12.8 volts
316 metremax
IS trunk
Trunk length will increase if device
population is reduced
316 metres
EthyleneGas Group
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Safe Area Zone 2 / Div 2 Zone 1 / Div 1
316 metres
Power &Ex protection
only
12 instruments
Power drawnin either direction
Cable protectionrequired
Power Supply as a IIB RepeaterPower Supply as a IIB Repeater
24volts
316 metres1.8 kms
Power,Repeater &
Ex protection
24volts
A similar scenario exists for a IIC repeater
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Safe Area Zone 2 / Div 2 Zone 1 / Div 1
1.8 kms
Power,Repeater &
Ex protection
Power drawnin either direction
Power Supply as a RepeaterPower Supply as a Repeater
Host probably has no Ex protection in powering the 912x device : Cable is a non-arcing circuit due to incendive level of energy Cable protection required - hazardous area wiring may not
be disconnected to reveal floating wires Repeater terminals carry limited energy; hence circuit is
non-incendive and power plug may be removed
912x device may power host equipment (max 30 mA) and power plug may be removed
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The ‘CE’ Mark
Confirms compliance with allrelevant Community directives
ATEX CertificationATEX Certification
x Confirms compliance withATEX
or previousFlammable Atmosphere Directive
The ‘Explosive Atmosphere’ Mark
Conformite European
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CENELEC / IECCENELEC / IEC
[E Ex ib] IIC T4 -40 OC < Tamb < +70 OC
Conformity with European Standard
Explosion protection symbol
Type of protection code
Apparatus Group (Hydrogen)
Temperature Class (Group II)
Referenced to ambientof -20 to +40 OC unlessindicated as above
T1 : 450 OCT2 : 300 OCT3 : 200 OCT4 : 135 OCT5 : 100 OCT6 : 85 OC
Equipment Marking - 9121 Power SupplyEquipment Marking - 9121 Power Supply
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CENELEC / IECCENELEC / IEC
[E Ex ib] IIC T4 -40 OC < Tamb < +70 OC
Conformity with European Standard
Explosion protection symbol
Type of protection code
Apparatus Group (Hydrogen)
Temperature Class (Group II)
Referenced to ambientof -20 to +40 OC unlessindicated as above
T1 : 450 OCT2 : 300 OCT3 : 200 OCT4 : 135 OCT5 : 100 OCT6 : 85 OC
Equipment Marking - 9121 Power SupplyEquipment Marking - 9121 Power Supply
[ ] indicates the apparatus is safe area mounted ‘associated apparatus’ suitable
for connection to Ex ib equipment
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ATEXATEX
CE mark
EU Explosive Atmosphere Symbol
I : MiningII : Non-Mining
M1 : energisedM2 : de-energised1 : Zone 0, 202 : Zone 1, 213 : Zone 2, 22
Type of explosive atmosphere(Group II)
G : Gas, vapour, mistD : Dust
Equipment Category
Equipment Group
Ref to Notified Body responsible for testing
II (2) GD0600
Equipment Marking - 9121 Power SupplyEquipment Marking - 9121 Power Supply
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BAS 02 ATEX 7276
Additional information on product :Safety parameters, where applicableYear of manufacture & Serial No.Name & address of manufacturerManufacturers type identification
[E Ex ib] IIC T4 -40 OC < Tamb < +70 OC
CENELEC / IECCENELEC / IEC
ATEXATEX II (2) GD0600
EC-type examinationcertificate
EC-type examinationcertificate
ATEX Category 2 certificationATEX Category 2 certification
9121 - BASEEFA Certification9121 - BASEEFA Certification
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MTL 02 ATEX 9121X
E Ex nA IIC T4 -40 OC < Tamb < +70 OC
CENELEC / IECCENELEC / IEC
ATEXATEX II 3 GD
MTL Declaration of Conformity
MTL Declaration of Conformity
ATEX Category 3 certification justifyingmounting the 9121 power supply in Zone 2
ATEX Category 3 certification justifyingmounting the 9121 power supply in Zone 2
9121X refers to special conditions of use :> power supply is installed in an appropriate enclosure> it must be protected from large supply transients
9121X refers to special conditions of use :> power supply is installed in an appropriate enclosure> it must be protected from large supply transients
9121 - MTL Declaration of Conformity9121 - MTL Declaration of Conformity
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us 9122 - BASEEFA Certification9122 - BASEEFA Certification
BAS 02 ATEX 7277
[E Ex ib] IIB T4 -40 OC < Tamb < +70 OC
CENELEC / IECCENELEC / IEC
ATEXATEX II (2) GD0600
EC-type examinationcertificate
EC-type examinationcertificate
ATEX Category 2 certificationATEX Category 2 certification
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MTL 02 ATEX 9122X
E Ex nA IIB T4 -40 OC < Tamb < +70 OC
CENELEC / IECCENELEC / IEC
ATEXATEX II 3 GD
MTL Declaration of Conformity
MTL Declaration of Conformity
ATEX Category 3 certification justifyingmounting the 9122 power supply in Zone 2
ATEX Category 3 certification justifyingmounting the 9122 power supply in Zone 2
9122 - MTL Declaration of Conformity9122 - MTL Declaration of Conformity
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us Fieldbus Intrinsically Safe Concept
(FISCO)
Fieldbus Intrinsically Safe Concept (FISCO)
Adopting FISCO raises the issue :
Can Entity certified fieldbus equipment (non-FISCO) beincorporated into a FISCO network ?
9321-SC
YES
9323-SC
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Zone 1
I.S. Entity Spur Connections(non-FISCO devices)
I.S. Entity Spur Connections(non-FISCO devices)
9121-IS : IICoutput safety parameters :
14 V; 180 mA; 2.52 Wdeliver 12.0 V; 110 mA
9321-SCEntity spur connector
FISCOdevices
EEx ib IIC T4 II 2 (2) G
HUB
TEntity device to FF-816 has an input safety description of 24 V; 250 mA; 1.2 watts
9321-SC
Entity IS certifieddevice
Live workingthroughout
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us Fieldbus Intrinsically Safe Concept
(FISCO)
Fieldbus Intrinsically Safe Concept (FISCO)
The use of active current limitation restricts the categorisationto ‘EEx ib’, ie, connection to Zone 1 only
Can a fieldbus device be installed in a Zone 0 by adding furtherprotection to achieve ‘ia’ status ?
9322-SC
YES
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Zone 1
Zone0
Networking into Zone 0Networking into Zone 0
Useablewith either
9121-IS : IIC9122-IS : IIB
9322-SCZone 0 spur connector
II 2 (1) G EEx ib IIC T4II (1) G EEx [ia] IIC
NODE
T
FISCOdevices
9322-SC
ia : Zone 0energy limit
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WiringComponents
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us Wiring Components - Megablock SeriesWiring Components - Megablock Series
Terminator
Short-circuit protection option using SpurGuard
Megablocks : DIN-rail mounting Fieldbus network
hubs connect multiple field devices to trunk
network minimise hand wiring
network integrity maintained during
connection / disconnection of
individual devices LED indicates minimum 9 volts
present at hub Megablocks available in
2, 4 & 8-way (10-way) versions Megablock terminator available
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SpurGuardshort circuit protection
- visual indication of fault
Power LED >= 9V
Securable, pluggable connectors
Trunk / Home run
Megablock SeriesMegablock Series
Trunk / Home run
Fielddevice
connection
8-wayMegablock
Optional
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Choice of junction boxUse site standard
suitable for environment
standardinstrument cable
spur
terminator
trunk
4 + 8 drop = 12 drop Easy to retrofit Junction box for
specific application
Megablock SeriesMegablock Series
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System reliability and availability may be affected by the shorting of the fieldbus highway, by the failure of any individual fieldbus device, thus interrupting data communication across the entire bus segment could occur during installation or routine instrument maintenance
A SpurGuard™ is a current-limiting device that provides short circuitprotection to the fieldbus segment
By attaching a SpurGuard™ at each point where a field device is attachedto the segment home run cable, isolation of the network fromindividual device failures is achieved
SpurGuards™ are available with any Megablock a red LED indicates when a SpurGuard™ is providing overcurrent protection
Relcom SpurGuards™Relcom SpurGuards™
Because a SpurGuard™ leg draws power from thesegment when in short circuit mode, theirshort circuit current consumption must betaken into account during segment design
The SpurGuard™ short-circuit current is nominally60 mA
Trunk to Spur max. voltage drop = 0.4 volts
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Lightning StrikesLightning Strikes
Handlingthe
effect
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The purpose of lightning surge protectionin Fieldbus wiring is to minimize the induced voltages & currents and hence to minimise damage to Fieldbus equipment
a lightning strike might produce 100,000 Amps in a lightning rod
induced currents in nearby grounded metal objects may be several
thousand Amps induced current in the shield of a
fieldbus cable might be severalhundred Amps
Lightning StrikesLightning Strikes
90%
50%
10%
I (100 kA)PK
8µs
20µs
t
There is no remedy for direct lightning strikes the energies involved are too high but measures can be taken to minimize the effects of near-lightning
strikes on Fieldbus networks
Lightning is a short burst of very intense voltage and current. Even when a direct lightning strike is shunted to ground by a
lightning rod, it induces high voltages and currents in metalcomponents nearby
eg, the conductors & shield of Fieldbus cable
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Fieldbus
Local ‘ground’
Principles & PracticalitiesPrinciples & Practicalities
High potential across insulation on field
instrument
Flash-over
Flash-over
Induced Voltage V = L x I/ t
100kALocal Ground
Strike
High local potential on
building earthsystem
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The shield of the Fieldbus cable is grounded but according to the installation standard, in only one place
Single-point grounding eliminates current loops in the shield reduces induced noise in the signal concerned is a pre-requisite for an intrinsically safe circuit the shield is normally grounded at the control room
Any lightning strike in the field could produce a large current in the shieldthat needs to travel to the control room to pass to ground
in a long network a large shield voltage could occur by capacitive coupling a large voltage might appear on the internal
twisted pair A surge may be minimized by using a Transient Surge Suppressor
Transient Surge SuppressionTransient Surge Suppression
Shield
Transient SurgeSuppressor
Centralised controlequipment
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us Differential Voltage SuppressionDifferential Voltage Suppression
The next consideration is to minimize the voltage that might be
induced in the twisted-pair inside the shield
Due to the capacitance between the shield & each of the wires in
the twisted pair, a voltage change on the shield will induce a voltage on the
wires Using twisted-pair cable, the shield-to-wire capacitances for the
two wires are nearly equal hence the voltage induced in each of the wires in the twisted
pair will be identical (Common Mode Voltage effect)
The Fieldbus standard requires that the common mode
immunity of Fieldbus devices should be of a high order,
eg, Surge Protection Devices : FP32 = 225 volts DC trigger point TP32 = 120 volts DC trigger point
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The FP32 surge protection device prevents surges & transient
overvoltages conducted along the Trunk or Spurs of fieldbus
systems from damaging the associated electronics may be used at any point on a Trunk to safely divert any surges
to ground
The TP32 is the protection equivalent installed at an instrument
Fully automatic in operation, the devices react instantly to make sure
that equipment is never exposed to damaging surges between
lines or between lines & earth Reacting instantaneously to surges they then reset automatically
FP32 TP32
Protection DevicesProtection Devices
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us Surge Protection DeviceSurge Protection Device
Gasdischarge
tube
Lineinductors
Solid-statelimiters
Circuit fuses
Signallines
Circuitearth
Protectedequipment
90%
50%
10%
I (100 kA)PK
20µs
t
The multi-stage elements of the FP32 / TP32
use a combination of solid state electronics
and a gas filled discharge tube (GDT) to
provide surge protection up to 20kA
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us Power problems due to transient spikes Power problems due to transient spikes
Sag < 10% Surge < 10% Outage < 1%
Transient 85% to 90%
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TT
Hub
Powerconditioner
TrunkTerminator
Generalised Fieldbus connectionGeneralised Fieldbus connection
Powersupply
Powerdistributionpanel
IncomingAC supply
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Powerdistributionpanel
Host System protectionHost System protection
TT
Hub
Powerconditioner
TrunkTerminator
Powersupply
IncomingAC supply
MA 4000
FP32
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T
HubTrunk
Terminator
FP32
Field Device Protection - ‘compact’Field Device Protection - ‘compact’
All spurs less than : 50m horizontal or 10m vertical
Surge invasion from hostend of trunk
all devices are protected by one surge protection device in trunk
Spurs< 50m horizontal
< 10m vertical
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T
HubTrunk
Terminator
Spurs> 50m horizontal
> 10m vertical
FP32
Spurs greater than : 50m horizontal or 10m vertical
surge invasion from Hostend of trunk
surge protection installed to each device
Field Device Protection - ‘widespread’ Field Device Protection - ‘widespread’
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