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NRG 111-11Installation Instructions 810898-01Level ElectrodeNRG 111-11

�

GESTRA Steam Systems

GESTRA

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Contents

Usage for the intended purpose .............................................................................................................. 4Safety note ............................................................................................................................................. 4Danger ................................................................................................................................................... 4Classification pursuant to article 1 of the Pressure Equipment Directive (PED) ........................................ 4

Important NotesPage

Explanatory Notes

Scope of supply ...................................................................................................................................... 4Description ............................................................................................................................................. 5Function ................................................................................................................................................. 5System components ............................................................................................................................... 5Design ................................................................................................................................................... 5

NRG 111-11, step 1 ............................................................................................................................. 12NRG 111-11, step 2 ............................................................................................................................. 12Tools .................................................................................................................................................... 13Examples of installation ....................................................................................................................... 14Key ...................................................................................................................................................... 15

Installation

Wiring

NRG 111-11 ......................................................................................................................................... 15Wiring diagram .................................................................................................................................... 16Voltage table ........................................................................................................................................ 17Tools .................................................................................................................................................... 17

NRG 111-11 ........................................................................................................................................... 6Corrosion resistance .............................................................................................................................. 7Sizing ..................................................................................................................................................... 7Name plate / marking ............................................................................................................................. 7Dimensions ............................................................................................................................................ 8

Technical Data

NRG 111-11 ........................................................................................................................................... 9Key ...................................................................................................................................................... 11

Design

NRG 111-11 ......................................................................................................................................... 10Key ...................................................................................................................................................... 11

Functional Elements

3

Check wiring ........................................................................................................................................ 17Apply mains voltage ............................................................................................................................. 17

Contents – continued –

CommissioningPage

Declaration of Conformity ..................................................................................................................... 19

Annex

Water level limiter ................................................................................................................................ 18

Operation

Fault finding list for troubleshooting ..................................................................................................... 18

Operation Malfunctions

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Important Notes

Danger

When loosening the electrode steam or hot water might escape. This presents the dangerof severe scalding. It is therefore essential not to remove the electrode unless the boilerpressure is verified to be 0 barg.

The electrode is hot during operation. This presents the danger of severe burns to handsand arms. Installation and maintenance work should only be carried out when the systemis cold.If the internal ceramic insulation breaks hot steam may escape through the lateral reliefvent of the electrode stem.This presents the danger of severe scalding!Do not stand close to the electrode during operation.

Usage for the intended purpose

Use level electrode type NRG 111-11 only in conjunction with NRS 1-7 as water level limiter(low level alarm). The equipment must not be used in explosion risk areas.

Classification pursuant to article 1 of the Pressure Equipment Directive (PED)

Category IV

Designation Safety accessory

CE marking CE 0525

Safety Note

The equipment must only be installed and commissioned by qualified and adequately trainedpersonnel.

Maintenance and retrofitting must only be performed by entrusted personnel who – through adequatetraining – have achieved a recognized level of competence.

Explanatory Notes

Scope of supply

NRG 111-111 Level electrode NRG 111-111 Gasket 33 x 39 DIN 7603-1.43011 Sealing plug for M 20 connection1 Surface extension disk with grub screw1 Lock washer1 Installation manual

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Explanatory Notes – continued –

Description

The level electrode NRG 111-11 detects the min. liquid level (low level alarm) in a steam boiler. Theoperation of the electrode is based on the conducitivity measuring principle using the electricalconductivity of water for signalling one liquid level:■ Low level alarm (MIN alarm)

The NRG 111-11 is designed for use in conjunction with level switch NRS 1-7 as a self-monitoring lowlevel limiter with periodic self-checking (SMART) feature.Application in steam and pressurised hot water plants in accordance with TRD 604, sheet 1 and sheet 2(24h/72h operation) as well as EN 12952 and 12953.

The electrical equipment meets the requirements of the Regulations on Protection Circuits DIN VDE0116 (prEN 501565-1).

Function

Design

The water level limiter comprises the level electrode type NRG 111-11 and GESTRA level switch NRS1-7. The level electrode NRG 111-11 consists of two concentrically arranged electrodes (measuringelectrode and compensating electrode) which are isolated from each other by special insulatingseals.

The level limiter operation is based on the conductive measuring principle using the electricalconductivity of water for signalling water level. During normal, trouble-free operation the levelelectrode tip is immersed in boiler water and no low level alarm is given. A low level alarm will onlybe raised if the electrode tip is exposed for more than 3 seconds. A low level alarm will also beactivated if the insulating seals placed between the electrodes and the body are no longer pressuretight, allowing water to penetrate into the cavities between the body, tube and stud. However in thisinstance the alarm is caused by a malfunction of the electrode, and confirmation should always bedone by checking if there is water in the gauge glass. The equipment combination NRG 111-11 andNRS 1-7 provides fail safe protection against a first fault in accordance with TRD 604.

If the internal ceramic insulation breaks steam and hot water may escape through the lateral reliefvent of the electrode stem.

NRG 111-11:Level electrode with screwed connection 1" BSP, ISO 228-1. Fig. 1

System Components

NRS 1-7Level switch NRS 1-7, 0.5 µS version. The limiter features a two channel circuit (redundancy) and anautomatic periodic self-checking routine in accordance with DIN VDE 0116 (prEN 50156-1).

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NRG 111-11

Type approval no.TÜV· WB · 01-354EG 01 202 931-B-01-0077-01

Service pressureNRG 111-11: 183 barg (at 357 °C)

Connection1" BSP (to ISO 228-1)Flange PN 320, DN 50, DIN 2501-1 (optional)Flange PN 250, DN 80, DIN 2501-1 (optional)

MaterialsBody 3.2161 G AlSi8Cu3Stem 1.4529, X39CrMo17-1Measuring electrode 1.4401, X5CrNiMo17-12-2Electrode insulation: Special ceramic material

Lengths available 500 mm1000 mm1500 mm2000 mm2500 mm3000 mm

pH valueMax. admissible: 10

Cell constant C0.13 cm-1 with measuring surface extension

Response sensitivity0.5 µS/cm up to 400 µS/cm at 25 °C

Cable entryCable gland with integrated cable clampM 20 (2) (PG 16)

ProtectionIP 65 to DIN EN 60529

Max. admissible ambient temperature70 °C

WeightApprox. 1.8 kg

Technical Data

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Corrosion Resistance

If the unit is used for the intended purpose, its safety is not impaired by corrosion.

Technical Data – continued –

Sizing

The housing must not be subjected to sharp increases in pressure. Welds and flanges are designed towithstand dynamic loading (bending and alternative stress). The dimensional allowances for corrosionreflect the latest state of technology.

Name Plate / Marking

Designation

Fig. 1

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Technical Data – continued –

Dimensions

Fig. 2

b = 70

400

175

140

1" BSP, ISO 228-1

≥ 18

550

0, 1

000,

150

0,20

00, 2

500,

300

0

136

30

9

Fig. 5 Fig. 6

N 8

N10

0.5

Fig. 3 Fig. 4

1" BSP, ISO 228-1

∅ 4014

Design NRG 111-11

AB

CD

E

GF

I

H J

30

∅ 58

110

10

Functional Elements

Fig. 7

MAX 70 °C

MAX 95 %

Fig. 8

K L M L

P

O N

11

A Electrode rod

B Bore

C Spring

D Electrode tip

E Disk (measuring surface extension)

F Retaining ring

G Grub screw

H Gasket D 33x 39 DIN 7603-1.4301

I Seating surface

J Electrode thread

K Housing screws M 4

L Cable entry M 20x1.5

M Housing cover

N Terminal strip

O PE connection

P Plug

Key

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Attention

■ The seating surfaces of the standpipe or the flange provided on the vessel must beaccurately machined, see fig. 6.

■ Do not bend electrode tip when mounting.■ Use only ring joint (of stainless steel 1.4301) D 33x39 DIN 7603 supplied with the

electrode.■ Do not lag electrode body above the hexgonal section.■ Do not insulate electrode thread with hemp or PTFE tape.■ The leakage path between electrode and flange (mass) must be at least 14 mm, fig. 5■ Observe minimum distances and spacing dimensions when installing the electrode,

fig. 5

Installation

NRG 111-11, step 1

1. Screw electrode tip D into measuring electrode A. Fig. 32. Carefully determine required measuring length of electrode. Observe min. length, Fig. 23. Mark length of electrode tip D.4. Unscrew electrode tip D from measuring electrode A and cut tip.5. After visual inspection screw electrode tip D into measuring electrode A. Slide spring C along

electrode tip D, so that its bent end completely enters into small bore B.6. Fit surface extension disk E to electrode tip end and make sure that electrode tip protrudes 2 mm

beyond the bottom of the surface extension disk. Fix the surface extension disk in this position withthe grub screw G. Push lock washer F over electrode tip end against surface extension disk E.

NRG 111-11, step 2

1. Check seating surfaces. Fig. 62. Place joint ring E onto seating surface F of electrode. Fig. 43. Apply a light smear of silicone grease G (e. g. Molykote® 111) to electrode thread.4. Screw level electrode into threads or flange provided on vesssel and tighten with a 41 mm open-end

spanner. The torque required is 475 Nm when cold.

Molykote® 111 is a registered trademark of DOW Corning Corp., Midland Michigan, USA

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Note

■ For the approval of the boiler standpipe the relevant regulationsmust be considered.

■ Refer to page 14 for four typical installation examples.

■ The inclination angle of the electrode must not exceed 45°. The max. length of theelectrode rod is 1600 mm.

Tools

■ Open-end spanner 13 mm A. F.■ Open-end spanner 41 mm A. F.

■ Hacksaw■ Flat file, medium cut

Installation – continued –

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Examples of Installation

∅

20

20

Fig. 9 Fig. 10

Fig. 11

DN 50

1" BSP

1" BSP

≥10

∅ 20≤ 90°

12

8

3

5

90

7

4

11

1

1

DN 80

Cent

re d

ista

nce

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1 Flange PN 320, DN 50, DIN 2505-1Flange PN 250, DN 80, DIN 2505-1

2 For the approval of the boiler standpipe with connecting flange the relevant regulations must beconsidered.

3 Vent hole Provide vent hole as close to the boiler wall as possible!

4 High water (HW)

5 Electrode rod d = 8 mm

7 Protection tube DN 100

8 Electrode distance ≥ 14 mm

9 Low water (LW)

0 Reducer DIN 2616-2, K-88.9 x 3.2- 42.4 x 2.6 W

Key

Wiring

NRG 111-11

Note that screened four-core cable, e. g. I-Y(St)Y 2 x 2 x 0.8 or LIYCY 4 x 0.5 mm2 is required for wiringto the electrode.Max. cable length 30 m with water conductivity from 0.5 µS/cm.

Max. cable length 15 m with water conductivity from 0.5 µS/cm when used in conjunction with inverterURN 1 (24 d. c.).1. Undo screws K and remove housing cover M. Fig. 72. Unscrew union nuts of cable entry L.3. Slacken plug P with 18 mm open-end spanner but do not remove, fig. 8

The electrode terminal box can now be turned through +/– 180°.4. Turn electrode terminal box into desired position (+/– 180°).

5. Tighten plug P slightly.6. Remove terminal strip N from board.

7. Connect terminal strip according to wiring diagram.8. Affix terminal strip.

9. Re-attach housing cover M and fix it with screws K.

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Wiring – continued –

Wiring Diagram

Fig. 12

Compensation electrode

Compensation electrode

Measuring electrode

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Apply mains voltage to level switch NRS 1-7.

Commissioning

Make sure that the electrode NRG 111-11 is connected to the level switch NRS 1-7 according to thewiring diagram. Fig. 12

Check wiring

Apply mains voltage

Wiring – continued –

Voltage table

Use this voltage table to check whether the level electrode is submerged or if there is a malfunction.Observe the wiring diagram of the NRS 1-7, fig. 12

Note

■ The self-checking routine of the amplifier NRS 1-7 reduces U1-2

every 40 sec.to 0 volt!

■ Use sealing plug for cable entry L if only one cable runs to the terminal box.Insert sealing plug supplied with the electrode (IP 65)!

Tools

Attention

■ Screwdriver for cross head screws, size 1■ Screwdriver for slotted screws, size 2.5, completely insulated according to DIN VDE 0680-1

■ Open-end spanner 18 (19) mm A. F.

U1-2

10 Veff 0.5 µS/cm,C=0.13 cm-1

U1-4 U2-4

submerged exposed malfunction (submerged / alarm)

U1-2

2<

U1-2

2≥ U

1-4≤

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Operation Malfunctions

Fault finding list for troubleshooting

Level electrode immersed – low level alarm

Fault: Mains voltage not applied.Remedy: Apply mains voltage. Connect electrode according to wiring diagram.

Fault: The electrode body does not have earth connection to the boiler.Remedy: Clean seating surfaces and insert metal joint ring (of stainless steel 1.4301)

D 33 x 39 to DIN 7603.Do not insulate level electrode with hemp or PTFE tape!

Fault: The internal insulation of the electrode rod is damaged.Remedy: Replace level electrode.

Level below “low level limit” – no function

Fault: The electrode rods have earth contact.Remedy: Check and change installation position if necessary.

Fault: The vent hole in the protection tube does not exist, is obstructed or flooded.Remedy: Check protection tube and, if necessary, provide vent hole.

Fault: The isolating valves of the external measuring pot (optional extra) are closed.Remedy: Open isolating valves.

Operation

Application in conjunction with level switch NRS 1-7 in steam and pressurised hot water plants inaccordance with TRD 401, TRD 602, TRD 604, EN 12952, EN 12953 or according to other nationalregulations.

Water level limiter

Note

■ To analyse and eliminate malfunctions use “Fault finding list for troubleshooting” onpage 18!

If faults occur that are not listed above or cannot be corrected, please contact our service centre orauthorized agency in your country.

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Declaration of Conformity

Annex

We hereby declare that the equipment NRG 111-11 conforms to the following European guidelines:■ LV guideline 73/23/eec version 93/68/eec■ EMC guideline 89/336/eec version 93/68/eec■ Pressure Equipment Directive (PED) No. 97/23/eec of 29 May 1997

The electrodes are safety accessories as defined in paragraph 1, section 2.1.3 PED.Applied conformity assessment procedure: Annex III, Module B and D.The guidelines and directives are based on the following harmonised standards:■ LV standard DIN EN 50178■ EMC standard DIN EN 50 081-2, DIN EN 61000-6-2

Other technical regulations applied: VdTÜV Bulletin “Wasserstand 100”(= Water Level 100) 04.1990 and draft 08.2001.

This declaration is no longer valid if modifications are made to the equipment without consultationwith us.

Bremen, 10th October 2003GESTRA AG

Dipl.-Ing. Lars Bohl(Academically qualified engineer)

Quality Assurance Manager

Dipl.-Ing. Stefan Bode(Academically qualified engineer)

Head of R & D Dept. Electronics

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Great Britain

Flowserve Flow Control (UK) Ltd.Burrel Road, Haywards HeathWest Sussex RH 16 1TLTel. 00 44 14 44 / 31 44 00Fax 00 44 14 44 / 31 45 57E-mail: gestraukinfo@flowserve.com

Italia

Flowserve S.p.A.Flow Control DivisionVia Prealpi, 30l-20032 Cormano (MI)Tel. 00 39 02 / 66 32 51Fax 00 39 02 / 66 32 55 60E-mail: infoitaly@flowserve.com

GESTRA ESPAÑOLA S.A.Luis Cabrera, 86-88E-28002 MadridTel. 00 34 91 / 51 52 032Fax 00 34 91 / 41 36 747; 51 52 036E-mail: aromero@flowserve.com

España

Flowserve DALCO Steam Products2601 Grassland DriveLouisville, KY 40299Tel.: 00 15 02 / 4 95 01 54, 4 95 17 88Fax: 00 15 02 / 4 95 16 08E-Mail: dgoodwin@flowserve.com

USA

Portugal

Flowserve Portuguesa, Lda.Av. Dr. Antunes Guimarães, 1159Porto 4100-082Tel. 00351 22 / 6 19 87 70Fax 003 51 22 / 6 10 75 75E-mail: jtavares@flowserve.com

Poland

GESTRA POLONIA Spolka z.o.o.Ul. Schuberta 104PL - 80-172 GdanskTel. 00 48 58 /306 10 -02 od 10Fax 00 48 58 /306 33 00E-mail: gestra@gestra.pl

Weltweite Vertretungen finden Sie unter:

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GESTRA AGPostfach 10 54 60, D-28054 BremenMünchener Str. 77, D-28215 BremenTelefon +49 (0) 421 35 03 - 0Telefax +49 (0) 421 35 03 - 393E-Mail gestra.ag@flowserve.comInternet www.gestra.de

810898-01/1004c · © 2003 GESTRA AG · Bremen · Printed in Germany

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