GESTRA NRS 2-3 User manual

1
NRS 2-3
Installation Instructions 810414-02
Level Switch Type
NRS 2-3
GESTRA Steam Systems
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Contents
Usage for the intended purpose ..............................................................................................................4
Safety note ............................................................................................................................................4
Danger ...................................................................................................................................................4
Attention................................................................................................................................................. 4
ATEX (Atmosphère Explosible).................................................................................................................4
Important Notes
Page
Explanatory Notes
Scope of supply ......................................................................................................................................5
System description .................................................................................................................................5
Function .................................................................................................................................................5
Designs ..................................................................................................................................................5
Design “b”............................................................................................................................................ 10
Design “c”/“d”......................................................................................................................................10
Tools ....................................................................................................................................................10
Installation
Electrical Connection
Design “b”............................................................................................................................................ 11
Wiring diagram for design “b”...............................................................................................................11
Design “c”/“d”......................................................................................................................................12
Wiring diagram for design “c”/“d” ........................................................................................................12
Attention ..............................................................................................................................................12
Key to wiring diagram...........................................................................................................................13
NRS 2-3 .................................................................................................................................................6
Dimensions ............................................................................................................................................7
Technical Data
NRS 2-3 .................................................................................................................................................8
Key.........................................................................................................................................................9
Functional Elements

3
Danger .................................................................................................................................................14
Note .....................................................................................................................................................14
Checking wiring....................................................................................................................................14
Applying mains voltage .......................................................................................................................14
Adjusting switchpoint “Low Level”........................................................................................................14
Adjusting switchpoint “Pump ON”.........................................................................................................14
Adjusting switchpoint “Pump OFF”........................................................................................................ 14
Adjusting switchpoint “High Level” ....................................................................................................... 15
Note .....................................................................................................................................................15
Table switchpoints ................................................................................................................................ 15
Contents – continued –
Commissioning
Page
Danger .................................................................................................................................................16
Note .....................................................................................................................................................16
Correct switchpoints............................................................................................................................. 16
Check power ........................................................................................................................................16
Operation
Danger .................................................................................................................................................17
Fault finding list for troubleshooting......................................................................................................17
Operational Malfunctions
Declaration of conformity......................................................................................................................18
Annex

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Important Notes
Danger
The terminal strip of the NRS 2-3 is live during operation. This presents the danger of
electric shock.
Cut off power supply before inserting or removing the 19" slide-in unit and before carrying
out any installation or maintenance work.
Usage for the intended purpose
Use level switch NRS 2-3 only in conjunction with GESTRA level transmitter NRGT 26-1 for pump
control.
Safety note
The equipment must only be installed and commissioned by qualified and adequately trained per-
sonnel.
Maintenance and retrofitting must only be performed by entrusted personnel who – through adequate
training – have achieved a recognised level of competence.
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.
Application in Ex zones 1, 2 (1999/92/EC). The equipment does not bear an Ex marking.
The suitability of the Zener barrier is certified in a separate document.
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.

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Scope of supply
NRS 2-3, design “b”
1 Level switch NRS 2-3
1 Mounting panel for installation
in control cabinets
1 Installation manual
Explanatory Notes
System description
The level switch type NRS 2-3 is an analogue electronic control instrument (pump control) for the
capacitance level transmitter type NRGT 26-1S.
In combination with this transmitter the equipment can signal the following levels:
High level, low level, level control unit on/off
and can be used as level controller for steam boilers and pressurized hot-water plants.
Function
The standardized input current signal is transformed by the resistor into a level-proportional voltage
and then preamplified. This voltage is fed to three voltage comparators V1, V2, V3 and compared with
adjustable reference voltages. Depending on the comparison result the relays will be (de)energized as
follows:
■If the level voltage across V1 is higher than the reference voltage, relay 1 is de-energized and the
red LED Dilluminated.
■If the level voltage across V3 is lower than the reference voltage, relay 3 is de-energized and the
red LED Ailluminated.
■If the level voltage across V3 is higher than the reference voltage, relay 3 is energized and the red
LED Aextinguishes.
V2 works as switching controller, e. g. for the boiler feed pump.
■If the level voltage across V2 is lower than the reference voltage, relay 2 will switch on the pump.
The yellow LED Bis illuminated.
The pump switches off in accordance with the adjusted hysteresis, which is adjustable over 1 % to
50 % of the level transmitter measuring range. Once the adjusted value is reached the relay 2 switches
off the pump and the green LED Cis illuminated.
Designs
Design “b”
19" slide-in unit to DIN 41494 part 5, installed on a mounting panel for installation in control cabinets
with screw-type terminals at the top and bottom.
Design “c”
19" slide-in unit with guide rails and 32 pole screw-type connector for the installation in 19" mounting
panels acc. to DIN 41494 part 5.
Design “d”
19" spare slide-in unit
NRS 2-3, design “c”
1 Level switch NRS 2-3
2 Guide rails
1 32 pole screw-type connector
1 Installation manual
NRS 2-3, design “d”
1 Level switch NRS 2-3
1 Installation manual

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NRS 2-3
Technical Data
Type approval no.
GL 99249-96HH
LR 98/20074
BV 10617/Bo
RINA No ELE/30298/2
KR HMB06190-MS002
DNV A-8394
Mains voltage
230 V ± 10 %, 50/60 Hz
115 V ± 10 %, 50/60 Hz (option)
24 V ± 10 %, 50/60 Hz (option)
Power consumption
5 VA
Input
4 – 20 mA (coming from level transmitter)
Output
3 volt-free relay contacts
Max. contact rating with switching voltages of 24 V, 115 V and 230 V AC: 4 A resistive,
0.75 A inductive at cos ϕ= 0.5.
Max. contact rating with a switching voltage of 24 V DC: 4 A
Service life of relay: 30x106switching cycles.
Limit value high level /low level
Continuously adjustable within measuring range of level transmitter
Switchpoints pump on/off
Continuously adjustable within 1 – 50 % of the measuring range of level transmitter
Indicators and adjustors
1 red LED “high level”, 1 red LED “low level”, 1 yellow LED “pump on”, 1 green LED “pump off”.
4 adjustors for high level /low level and pump on/off.
Protection
IP 10 to DIN EN 60529
Max. admissible ambient temperature
0 °C to +70 °C
Case
19" slide-in unit with front panel to DIN 41494 part 5 and rear 32 way Euro card connector to
DIN 41612 installed in a mounting panel or for installation in 19" mounting panel.
Front panel, mounting panel: aluminium
Wiring
Design “b”: screw-type terminal strips at the back of the mounting panel, max. conductor size 1.5 mm2
Design “c”: 32 pole screw-type connector at the back of the 19" mounting panel,
max. conductor size 1.5 mm2
Supply line to level transmitter: screened two-core cable, conductor size 0.5 mm2, max. cable length 150 m
Internal fuse
Glass cartridge fine-wire fuse M 0.05 A, 5 x 20, replaceable
Weight
approx. 0.8 kg

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NRS 2-3
MAX
MIN
OFF
ON
87 9 10 11 12 13 14 15
17
1665
4
3
2
1
Technical Data – continued –
Dimensions
Fig. 1
67.7
80
180
88
207
∅6
NRS 2-3
MAX
MIN
OFF
ON
169 45.3 (9TE)
128.5
(TE = division units)
(1 TE = 5.08 mm)

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IP 10
NRS 2-3
MAX
MIN
OFF
ON
87 9 10 11 12 13 14 15
17
1665
4
3
2
1
NRS 2-3
MAX
MIN
OFF
ON
Functional Elements
NRS 2-3
Fig. 2
K
L
J
F
E
A
B
C
D
I
H
MAX 95 %
MAX 70 ° C

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A LED “Low Level”
B LED “Pump on”
C LED “Pump off”
D LED “High Level”
E Adjustor for high level
F Adjustor for pump off
H Adjustor for pump on
I Adjustor for low level
J Fixing screws
K Screw-type terminal strip
L 32way Euro card connector
Functional Elements – continued –
Key

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Installation
Design “b”
1. Drill four holes into the mounting panel of the control cabinet.
2. Put level switch onto the mounting panel and align.
3. Insert matching screws and fasten.
Design “c”/“d”
1. Install guide rails and screw-type connector into 19" mounting panel.
2. Insert 19" slide-in unit into the guide rails until it hits the stop.
3. Fasten the fixing screws J.
Tools
■Screwdriver for slotted screws, size 2 mm, 5 mm, completely insulated to VDE 0680