GESTRA NRG 16-50S User manual

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EN
English
Level Electrode
NRG 16-50S
Original Installation Instructions
819013-01

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Contents
Usage for the intended purpose ..............................................................................................................4
Function .................................................................................................................................................4
Safety note .............................................................................................................................................5
Scope of supply ......................................................................................................................................5
Important notes
Page
NRG 16-50 S ..........................................................................................................................................6
Name plate/marking ...............................................................................................................................6
Dimensions NRG 16-50 S ......................................................................................................................7
Technical data
NRG 16-50 S ..........................................................................................................................................8
NRG 16-50 S, step 1...............................................................................................................................9
NRG 16-50 S, step 2...............................................................................................................................9
Tools.......................................................................................................................................................9
Examples of installation ........................................................................................................................10
Key.......................................................................................................................................................11
Installation
Electrical connection
NRG 16-50 S with four-pole connector..................................................................................................12
Connection of level electrode ................................................................................................................13
NRG 16-50 S with four-pole connector..................................................................................................13
Tools.....................................................................................................................................................13
Wiring diagram .....................................................................................................................................14
Key.......................................................................................................................................................14

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Commissioning, fault indication and remedy
Danger .................................................................................................................................................15
Removing and disposing of electrode....................................................................................................15
Note .....................................................................................................................................................15
Removing and disposing of electrode
NRG 16-50 S ........................................................................................................................................15
Contents – continued –
Page

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Important Notes
Usage for the intended purpose
The level electrode NRG 16-50 S is used in conjunction with level switch NRS 1-50 (de-energizing
delay: 15 seconds) as water-level limiter for steam boilers and (pressurized) hot-water installations on
board of seagoing vessels, mobile offshore platforms or river boats.
Water level limiters switch off the heating when the water level falls below the set minimum level (low
water).
Function
When the water level falls below the low level, the level electrode is exposed and a low level alarm is
triggered in the level switch NRS 1-50. This switchpoint “Low water level (LW)” is determined by the
length of the electrode tip.
After the de-energizing delay has elapsed, the two output contacts of the level switch NRS 1-50 will
open the safety circuit for the heating. The equipment has a factory set default de-energizing delay of
15 seconds to compensate for the the movements of the ship.
The self-monitoring function ensures that an alarm will also be triggered if the electrode insulation is
contaminated or has developed a leak or if there is a malfunction in the electrical connection.
The level electrode is installed inside steam boilers, vessels or inlet lines of hot-water systems. The
protective tube mounted on site (see section Examples of Installation (pages 10, 11)) ensures correct
functioning.
If the level electrode is installed in an isolatable level pot outside the boiler, make sure that the
connecting lines are rinsed regularly. In addition, the logic unit SRL 6-50 is required to monitor the
purging times and the purging sequence.
If the connecting lines for steam ≥ 40 mm and water ≥ 100 mm, the installation is considered to be
internal. In this case the rinsing processes do not have to be monitored.

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Important Notes – continued –
Safety note
Danger
When loosening the level electrode steam or hot water might escape!
This presents the risk of severe scalding all over the body!
It is therefore essential not to dismantle the level electrode unless the boiler pressure is
verified to be 0 bar.
The level electrode becomes hot during operation.
Risk of severe burns to hands and arms.
Before carrying out installation and maintenance work make sure that the equipment is
cold.
Attention
The name plate specifies the technical features of the equipment. Do not commission or
operate any item of equipment that does not bear its specific name plate.
Water level limiters are safety devices and must only be installed, wired 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.
Scope of supply
NRG 16-50 S
1 Level electrode NRG 16-50 S, PN 40, DN 50
1 Installation manual