Flowserve NRG16-12 User Manual
GESTRA
GESTRA Steam Systems
NRG 16-12
NRG 17-12
NRG 19-12
Installation Instructions 818626-00
Level Electrode
NRG 16-12, NRG 17-12, NRG 19-12
1
2
Contents
Page
Important Notes
Usage for the intended purpose ..............................................................................................................4
Safety note .............................................................................................................................................4
Danger ...................................................................................................................................................4
ATEX (Atmosphère Explosible) .................................................................................................................4
Explanatory Notes
Scope of supply .................................................................................................................................. 4-5
Description .............................................................................................................................................5
Function .................................................................................................................................................5
System components ...............................................................................................................................5
Design ....................................................................................................................................................6
Technical Data
NRG 16-12, NRG 17-12, NRG 19-12 .......................................................................................................
Corrosion resistance ...............................................................................................................................7
Sizing .....................................................................................................................................................7
Name plate / marking .............................................................................................................................7
Dimensions .............................................................................................................................................8
Design
NRG 1...-12 ............................................................................................................................................9
Key ....................................................................................................................................................... 11
Functional Elements
NRG 1...-12 ..........................................................................................................................................10
Key ....................................................................................................................................................... 11
Installation
NRG 1...-12, step 1 ............................................................................................................................... 12
NRG 1...-12, step 2 ............................................................................................................................... 12
Attention ............................................................................................................................................... 12
Important notes ....................................................................................................................................13
Tools .....................................................................................................................................................13
Examples of installation ........................................................................................................................14
Key ....................................................................................................................................................... 15
6
Contents – continued –
Page
Wiring
NRG 1...-12 ..........................................................................................................................................15
Wiring diagram .....................................................................................................................................16
Voltage table .........................................................................................................................................17
Note .....................................................................................................................................................17
Tools .....................................................................................................................................................17
Commissioning
Check wiring ........................................................................................................................................17
Apply mains voltage..............................................................................................................................17
Operation
High-level alarm ...................................................................................................................................18
Note .....................................................................................................................................................18
Operational Malfunctions
Fault-finding list for troubleshooting ......................................................................................................18
Decommissioning
Danger .................................................................................................................................................19
Disposal................................................................................................................................................19
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4
Important Notes
Usage for the intended purpose
Use level electrodes NRG 16-12, NRG 17-12 and NRG 19-12 only in conjunction with level switch NRS
1-8 for water-level limiting (high level alarm).
Safety note
The equipment must only be installed and commissioned by qualified and competent staff.
Retrofitting and maintenance work must only be performed by qualified staff – who through adequate
training – have achieved a recognised level of competence.
Danger
When loosening the electrode steam or hot water might escape.
This presents the danger of severe scalds to the whole body.
It is essential not to mount or dismantle the electrode unless the boiler pressure is
verified to be 0 bar. The electrode becomes hot during operation. Touching the hot
equipment presents the risk of severe burns to hands and arms. All installation and
maintenance work must only be performed when the equipment is cold.
ATEX (Atmosphère Explosible)
The equipment constitutes a simple item of electrical equipment as defined in DIN EN 50020 section
5.4. According to the European Directive ATEX 94/9/EC the equipment may only be used in potentially
explosive atmospheres if it is provided with approved Zener barriers.
Applicable in Ex zones 1, 2 (1999/92/EC). The equipment does not bear an Ex marking. The suitability
of the Zener barriers is certified in a separate document.
Explanatory Notes
Scope of supply
NRG 16-12
1 Level electrode NRG 16-12, PN 40
1 Joint ring 27 x 32, form D, DIN 7603, 1.4301, bright-annealed
1 Disk with set screw (measuring surface extension) – optional
1 Retaining ring – optional
1 Installation manual
NRG 17-12
1 Level electrode NRG 17-12, PN 63
1 Joint ring 27 x 32, form D, DIN 7603, 1.4301, bright-annealed
1 Disk with set screw (measuring surface extension) – optional
1 Retaining ring – optional
1 Installation manual
Explanatory Notes – continued –
Scope of supply – continued –
NRG 19-12
1 Level electrode NRG 19-12, PN 160
1 Joint ring 27 x 32, form D, DIN 7603, 1.4301, bright-annealed
1 Disk with set screw (measuring surface extension) – optional
1 Retaining ring – optional
1 Installation manual
Description
The level electrode NRG 1...-12 detects the max. liquid level (high level alarm) in a steam boiler.
The operation of the electrode is based on the conductivity measuring principle using the electrical
conductivity of water for signaling one liquid level:
■ High level alarm
The NRG 1...-12 is designed for use in conjunction with level switch NRS 1-8 as a self-monitoring low
level 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 (24 h/72 h operation) as well as EN 12952 and EN 12953.
The electrical equipment meets the requirements of the Regulations on Protection Circuits
DIN VDE 0116.
Function
The water level limiter comprises a level electrode type NRG 1...-12 and a level switch type NRS 1-8.
The level electrode NRG 1...-12 consists of a pressure-tight measuring electrode. The electrode is
insulated with a plastic sleeve.
The high level limiter is based on the conductive measuring principle using the electrical conductivity of
water for signaling water level. During normal, trouble-free operation the level electrode tip is not
immersed in boiler water and no high level alarm is given. A high level alarm will only be raised if the
electrode tip is submerged for more than 3 seconds. A high level alarm will also be activated if the
insulating seals placed between the electrodes and the body are no longer pressure tight, allowing
water to penetrate into the body. However in this instance the alarm is caused by a malfunction of the
electrode, and confirmation should always be done by checking the water level in the gauge glass.
The equipment combination NRG 1...-12 and NRS 1-8 provides fail safe protection against a first fault in
accordance with TRD 604.
System components
NRS 1-8
Level switch NRS 1-8. Two channel level limiter (redundancy) with periodic self-checking routine to
DIN VDE 0116.
5
6
Explanatory Notes – continued –
Design
NRS 1...-12
Screwed ¾" BSP, ISO 228-1,
Fig. 3, Fig. 4, Fig. 5.
Technical Data
NRG 16-12, NRG 17-12, NRG 19-12
Type approval
TÜV· 01-02-0112
Service pressure
NRG 16-12: 32 bar at 238°C
NRG 17-12: 60 bar at 275°C
NRG 19-12: 100 bar at 311°C
Connection
¾" BSP, ISO 228-1
Materials
Stem: 1.4571 X6CrNiMoTi17-12-2
Measuring electrode: 1.4401, X5CrNiMo17-12-2
Electrode insulation: PEEK
Terminal box: Polyamide (PA)
Lengths available
500 mm 1000 mm
1500 mm
Cell constant C
-1
0.13 cm
with measuring surface extension
0.3 cm-1 without measuring surface extension
Response sensitivity
10
µS/cm at 25 °C, cell constant 0.3 cm
0.5 µS/cm at 25 °C, cell constant 0.13 cm
Terminal box
Four-pin connector, cable gland M 16 (PG 9)
Protection
IP 65 to EN 60529
Max. admissible ambient temperature
70 °C
Weight
Approx. 1.1 kg
-1
-1
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