GESTRA
GESTRA Steam Systems
NRG 16-11 |
|
NRG 17-11 |
|
NRG 19-11 |
|
Installation Instructions 818578-01 |
|
Level Electrode |
|
NRG 16-11, NRG 17-11, NRG 19-11 |
|
|
|
|
|
Contents
|
|
Page |
Important Notes |
|
|
Usage for the intended purpose............................................................................................................... |
4 |
|
Safety note.............................................................................................................................................. |
4 |
|
Danger.................................................................................................................................................... |
|
4 |
Attention................................................................................................................................................. |
4 |
|
PED (Pressure Equipment Directive)........................................................................................................ |
4 |
|
ATEX (Atmosphère Explosible).................................................................................................................. |
4 |
|
|
|
|
Explanatory Notes |
|
|
Scope of supply................................................................................................................................... |
4-5 |
|
Description.............................................................................................................................................. |
5 |
|
Function.................................................................................................................................................. |
5 |
|
System components................................................................................................................................ |
5 |
|
Design..................................................................................................................................................... |
|
6 |
|
|
|
Technical Data |
|
|
NRG 16-11, NRG 17-11, NRG 19-11........................................................................................................ |
6 |
|
Corrosion resistance................................................................................................................................ |
7 |
|
Sizing...................................................................................................................................................... |
|
7 |
Name plate / marking.............................................................................................................................. |
7 |
|
Dimensions............................................................................................................................................. |
8 |
|
|
|
|
Design |
|
|
NRG 1... |
-11............................................................................................................................................. |
9 |
Key........................................................................................................................................................ |
|
11 |
|
|
|
Functional Elements |
|
|
NRG 1... |
-11........................................................................................................................................... |
10 |
Key........................................................................................................................................................ |
|
11 |
|
|
|
Installation |
|
|
NRG 1... |
-11, step 1................................................................................................................................ |
12 |
NRG 1... |
-11, step 2................................................................................................................................ |
12 |
Attention............................................................................................................................................... |
12 |
|
Important notes..................................................................................................................................... |
13 |
|
Tools..................................................................................................................................................... |
|
13 |
Examples of installation......................................................................................................................... |
14 |
|
Key........................................................................................................................................................ |
|
15 |
Contents – continued – |
|
|
Page |
Wiring |
|
NRG 1...-11........................................................................................................................................... |
15 |
Wiring diagram...................................................................................................................................... |
16 |
Voltage table......................................................................................................................................... |
17 |
Note...................................................................................................................................................... |
17 |
Tools..................................................................................................................................................... |
17 |
Commissioning |
|
Check wiring......................................................................................................................................... |
17 |
Apply mains voltage.............................................................................................................................. |
17 |
Operation |
|
Low-level limiter................................................................................................................................... |
18 |
Note...................................................................................................................................................... |
18 |
Operational Malfunctions |
|
Fault-finding list for troubleshooting...................................................................................................... |
18 |
Decommissioning |
|
Danger.................................................................................................................................................. |
19 |
Disposal................................................................................................................................................ |
19 |
Annex |
|
Declaration of conformity...................................................................................................................... |
19 |
Important Notes
Usage for the intended purpose
Use level electrodes NRG 16-11, NRG 17-11 and NRG 19-11 only in conjunction with level switch NRS 1-7 for low-level limiting (low 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.
Attention
The name plate specifies the technical features of the equipment. Note that any piece of equipment without its specific name plate must neither be commissioned nor operated.
PED (Pressure Equipment Directive)
The equipment fulfills the requirements of the PED 97/23/EC. The equipment can be used with fluids of group 1 and 2. With CE marking (except for equipment according to section 3.3 of the PED).
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 16-11
1 Level electrode NRG 16-11, 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
Explanatory Notes – continued –
Scope of supply – continued –
NRG 17-11
1 Level electrode NRG 17-11, 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
NRG 19-11
1 Level electrode NRG 19-11, 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...-11 detects the min. liquid level (low 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:
■ Low level alarm
The NRG 1...-11 is designed for use in conjunction with level switch NRS 1-7 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 (prEN 50156).
Function
The water level limiter comprises a level electrode type NRG 1...-11 and a level switch type NRS 1-7. The level electrode NRG 1...-11 consists of two concentrically arranged electrodes (measuring electrode and compensating electrode) which are isolated from each other by special insulating seals.
The level limiter operation 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 immersed in boiler water and no low level alarm is given. A low level alarm will only be raised if the electrode tip is exposed for more than 3 seconds. A low 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 if there is water in the gauge glass. The equipment combination NRG 1...-11 and NRG 1-7 provides fail safe protection against a first fault in accordance with TRD 604.
System components
NRS 1-7
Level switch NRS 1-7. Two channel level limiter (redundancy) with periodic self-checking routine to DIN VDE 0116.
Explanatory Notes – continued –
Design
NRS 1...-11
Screwed ¾" BSP, ISO 228-1, Fig. 3, Fig. 4
Technical Data
NRG 16-11, NRG 17-11, NRG 19-11
Type approval
TÜV· WB·01-354
EG 01 202 931-B-01-0077
Service pressure
NRG 16-11: 32 bar at 238 °C NRG 17-11: 60 bar at 275 °C NRG 19-11: 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: Gylon®
Terminal box: Polyamide (PA)
Lengths available
500 mm |
1000 mm |
1500 mm |
2000 mm |
2500 mm |
3000 mm |
Cell constant C
0.13 cm-1 with measuring surface extension
0.3 cm-1 without measuring surface extension
Response sensitivity
10 S/cm at 25 °C, cell constant 0.3 cm-1 0.5 S/cm at 25 °C, cell constant 0.13 cm-1
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
Gylon® is a registered trademark of Garlock Sealing Technologies, Palmyra NY, USA
Loading...