GESTRA NRS 1-52 User manual

EN
English
Level Switch
NRS 1-52
Original Installation Instructions
819176-02

2NRS 1-52 - Installation Instructions - 819176-02
Contents
Page
Important Notes
Usage for the intended purpose...............................................................................................................4
Function..................................................................................................................................................4
Safety note..............................................................................................................................................4
Potentially explosive areas ......................................................................................................................5
Technical Data
NRS 1-52................................................................................................................................................6
Scope of supply .....................................................................................................................................7
In control cabinet: Mounting level switch
Dimensions NRS 1-5...............................................................................................................................8
Key .........................................................................................................................................................8
Installation in control cabinet...................................................................................................................8
Example name plate / marking................................................................................................................9
In control cabinet: Wiring level switch
Wiring diagram for level switch NRS 1-52 .............................................................................................10
Key .......................................................................................................................................................10
Connecting supply voltage ....................................................................................................................11
Connecting MIN/MAX output contact .....................................................................................................11
Connecting level electrode ....................................................................................................................11
Tools .....................................................................................................................................................11
In the plant: Wiring level electrode
Connecting several level electrodes.......................................................................................................12
Key .......................................................................................................................................................12
Connection of level electrode ................................................................................................................13
Factory settings
Commissioning procedure
Changing response sensitivity ...............................................................................................................14
Checking switchpoint and function........................................................................................................15

3
NRS 1-52 - Installation Instructions - 819176-02
Contents - continued -
Page
Operation, Alarm and Test
Indicators and adjustors ........................................................................................................................17
Further Notes
Action against high frequency interference............................................................................................18
Decommissioning / replacing the equipment.........................................................................................18
Disposal................................................................................................................................................18
Declaration of Conformity
Directives and Standards ...................................................................................................................19

4NRS 1-52 - Installation Instructions - 819176-02
Important Notes
Usage for the intended purpose
The level switch NRS 1-52 in conjunction with level electrodes NRG 1.-.. and ER 5. is used as limit
switch, for instance in steam boilers, (pressurized) hot-water installations as well as condensate and
feedwater tanks. The level switch detects and indicates a MIN and a MAX water level.
The level switch NRS 1-52 can be used in combination with the following level electrodes:
Level electrodes
NRG 10-52,
NRG 16-52
Electrode with
4 rods
NRG 16-36
Electrode with
4 rods
NRG 16-4
Electrode with
1 rod
ER 50
Electrode with
4 rods
ER 56
Electrode with
4 rods
The operation of the level switch NRS 1-52 is based on the conductive measuring principle using the
electrical conductivity of the water for signalling water level. The level switch is designed for different
electrical conductivities and for connecting two level electrodes.
The length of the associated electrode rod determines the MIN and MAX water level switchpoints.
The level switch detects that the MIN or MAX water level is reached when the corresponding electrode
rod is exposed or submerged. After the de-energizing delay has elapsed, the MIN or MAX output con-
tact is switched over. At the same time the MIN or MAX LED changes from green to red.
A MIN or MAX alarm can be simulated by pressing the button “Test”.
Function
Safety note
The equipment 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.
Danger
The terminal strips of the equipment are live during operation.
This presents the danger of electric shock!
Always cut off power supply to the equipment before mounting, removing or connect-
ing the terminal strips!
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.

5
NRS 1-52 - Installation Instructions - 819176-02
Important Notes - continued -
Potentially explosive areas
The equipment must not be used in potentially explosive areas.
Note
The level electrodes NRG 10-52, NRG 16-52, NRG 16-36, NRG 16-4 and ER 5.-1 are simple
items of electrical equipment as specified in EN 60079-11 section 5.7.
The equipment must be equipped with approved Zener barriers if used in potentially explo-
sive areas. Applicable in Ex zones 1, 2 (1999/92/EC).
The equipment does not bear an Ex marking.

6NRS 1-52 - Installation Instructions - 819176-02
NRS 1-52
Supply voltage
24 VDC +/– 20 %
Fuse
external 0.5 A (semi-delay)
Power consumption
2 VA
Connection of level electrode
2 inputs for level electrode NRG 10-52, NRG 16-52, NRG 16-36, NRG 16-4 and ER 5.-1,
4 poles with screen
Electrode voltage
5 VSS
Response sensitivity (Electrical conductivity of water at 25 °C)
> 0.5 ... < 1000 μS/cm or > 10 ... < 10 000 μS/cm (switch-selectable)
Outputs
2 volt-free change-over contacts, 8 A 250 V AC / 30 V DC cos ϕ= 1.
De-energizing delay: 3 sec.
Provide inductive loads with RC combinations according to manufacturer’s specification to ensure
interference suppression.
Indicators and adjustors
1 pushbutton “Test” for simulating MIN / MAX alarm,
2 red/green LEDs for indicating operating mode and MIN / MAX alarm,
1 green LED indicating “Power ON”,
1 code switch with 4 poles for changing the sensivity
Housing
Housing material: base: polycarbonate, black; front: polycarbonate, grey
Conductor size: 1 x 4.0 mm² solid per wire or
1 x 2.5 mm2per stranded wire with sleeve to DIN 46228 or
2 x 1.4 mm2per stranded wire with sleeve to DIN 46228;
Terminal strips can be detached
Fixing of housing: Mounting clip on supporting rail TH 35, EN 60715
Electrical safety
Pollution degree 2 for installation in control cabinet with protection IP 54, completely insulated
Protection
Housing: IP 40 to EN 60529
Terminal strip: IP 20 to EN 60529
Weight
approx. 0.2 kg
Technical Data

7
NRS 1-52 - Installation Instructions - 819176-02
NRS 1-52 - continued -
Ambient temperature
when system is switched on: 0 ° .... 55 °C,
during operation: -10 ... 55 °C
Transport temperature
–20 ... +80 °C (< 100 hours), defrosting time of the de-energized equipment before it can be put into
operation: 24 hours.
Storage temperature
–20 ... +70 °C, defrosting time of the de-energized equipment before it can be put into operation:
24 hours.
Relative humidity
max. 95 %, no moisture condensation
Technical Data - continued -
Scope of supply
NRS 1-52
1 Level switch NRS 1-52
1 Installation manual

8NRS 1-52 - Installation Instructions - 819176-02
In control cabinet: Mounting level switch
Dimensions NRS 1-5..
Fig. 1
1Upper terminal strip
2Lower terminal strip
Key
Installation in control cabinet
The level switch NRS 1-52 is clipped onto the support rail 4type TH 35, EN 60715 in the control
cabinet. Fig. 1
3Housing
4Supporting rail type TH 35, EN 60715
2
74
1
4 3
46 120

9
NRS 1-52 - Installation Instructions - 819176-02
In control cabinet: Mounting level switch - continued -
Example name plate / marking
Fig. 2
The date of production is printed on the side of the equipment.
1Terminals 16 - 23
2Wiring diagram, terminals 16 - 23
3Function
4Type designation
5Protection
6Protection class
7Operating data
(max. ambient temperature)
8Relay protection
9Safety note
0Manufacturer
aMaterial number, serial number
bConformity mark
cDisposal note
dType approval
eSupply voltage
fPower consumption
gExternal fuse for voltage supply
hWiring diagram, terminals 1 - 8
iTerminals 1 - 8
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10 NRS 1-52 - Installation Instructions - 819176-02
In control cabinet: Wiring level switch
Wiring diagram for level switch NRS 1-52
(–) (+)
579
5Connection of supply voltage 24 V DC with fuse 0.5 A (semi-delay) provided on site
6Reference electrode or vessel used as functional earth
7MIN electrode rod
8MAX electrode rod
9Central earthing point (CEP) in control cabinet
0MAX output contact
aMIN output contact
Key
16 17 18 19 20 21 22 23
12345678
MIN MAX
+-
8
a0
M 0.5 A
(semi-delay) 6
Fig. 3