GESTRA NRS 1-53 User manual

1
EN
English
Level Switch
NRS 1-53
Original Installation Instructions
819177-01

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Contents
Usage for the intended purpose ..............................................................................................................4
Function .................................................................................................................................................4
Safety note .............................................................................................................................................4
Important Notes
Page
Directives and Standards
VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)..........................................................................5
LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility) .......................................................5
ATEX (Atmosphère Explosible).................................................................................................................5
Note on the Declaration of Conformity / Declaration by the Manufacturer .........................................5
Dimensions NRS 1-53.............................................................................................................................8
Key.........................................................................................................................................................8
Installation in control cabinet ..................................................................................................................8
Name plate / marking .............................................................................................................................9
In control cabinet: Mounting level switch
Wiring diagram for level switch NRS 1-53.............................................................................................10
Key.......................................................................................................................................................10
Connecting supply voltage ....................................................................................................................11
Connecting MIN 1 / MIN 2 output contact..............................................................................................11
Connecting level electrode....................................................................................................................11
Tools.....................................................................................................................................................11
In control cabinet: Wiring level switch
Connecting several level electrodes ......................................................................................................12
Key.......................................................................................................................................................12
Examples of configuration NRS 1-53 / NRS 1-54, connection of several level electrodes.......................13
Connection of level electrode................................................................................................................14
In the plant: Wiring level electrode
NRS 1-53..........................................................................................................................................6 – 7
Scope of supply......................................................................................................................................7
Technical data

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Contents - continued -
Page
Changing response sensitivity...............................................................................................................15
Checking switchpoint and function .................................................................................................16 ,17
Commissioning procedure
Indications and operation......................................................................................................................18
Operation, alarm and test
Factory settings
Factory setting......................................................................................................................................14
Protection against high frequency interference .....................................................................................19
Decommissioning / replacing the equipment ........................................................................................19
Disposal................................................................................................................................................19
Further notes

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Important Notes
Usage for the intended purpose
The level switch NRS 1-53 in conjunction with level electrodes NRG 1.-.. and ER 5. is used as limit
switch, for instance in steam boiler and (pressurized) hot-water installations. The level switch detects
and indicates two low water levels (MIN 1, MIN 2).
The level switch NRS 1-53 can be used in combination with the following level electrodes:
Level electrodes
NRG 10-52,
electrode with
4 rods
NRG 16-52,
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 1-53 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.
If two electrode rods are associated and connected to the level switch, two different low water levels
(MIN 1 / MIN 2) can be detected and signalled. The length of the electrode rods determines the cor-
responding switchpoints.
As soon as the water falls below the preset low level (MIN 1 / MIN 2), the level switch detects that the
electrode rods are exposed. After the de-energizing delay the MIN 1 / MIN 2 output contact will be
switched over. At the same time the LEDs for MIN 1 and MIN 2 change from green to red.
Even if only one electrode rod is connected, both output contacts will be switched over after the de-
energizing delay and the LEDs change from green to red.
When the equipment is used as water level limiter, the safety circuit for the heating is opened by the
output contacts. The disconnection of the heating is interlocked in the external safety circuit and can
only be deactivated when the water level is sufficiently high.
By pressing the Test button, MIN 1 and MIN 2 alarms can be simulated.
Function
Safety note
The equipment fulfils a safety function and must only be installed, wired and commissioned by quali-
fied 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.

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Directives and Standards
VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)
The level switch NRS 1-53 in conjunction with level electrodes NRG 10-52, NRG 16-52,
NRG 16-4 and ER 5.-1 is type approved to VdTÜV Bulletin “Water Level 100”.
The VdTÜV Bulletin “Wasserstand (= Water Level) 100” specifies the requirements made on water level
control and limiting equipment for boilers.
ATEX (Atmosphère Explosible)
According to the European Directive 2014/34/EU the equipment must not be used in explosion risk areas.
Note
The level electrodes NRG 10-52, NRG 16-52, NRG 16-4 and ER 5.-1 are simple items of
electrical equipment as specified in EN 60079-11 section 5.7. According to the European
Directive 2014/34/EU the equipment must be equipped with approved Zener barriers if used
in potentially explosive areas.
Applicable in Ex zones 1, 2 (1999/92/EC).
The equipment does not bear an Ex marking.
LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility)
The equipment meets the requirements of the Low Voltage Directive 2014/35/EU and the EMC Direc-
tive 2014/30/EU.
Note on the Declaration of Conformity / Declaration by the Manufacturer
For details on the conformity of our equipment according to the European Directives see our Declara-
tion of Conformity or our Declaration of Manufacturer.
The current Declaration of Conformity / Declaration of Manufacturer are available in the Internet under
www.gestra.com/documents or can be requested from us.

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NRS 1-53
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 16-4 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 1 / MIN 2 alarm,
2 red/green LEDs for indicating operating mode and MIN 1 / MIN 2 alarm,
1 green LED indicating “Power ON”,
1 code switch with 4 poles for changing the sensitivity
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

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NRS 1-53 - 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
Approvals:
TÜV certificate VdTÜV Bulletin “Water Lever 100”:
Requirements made on water level limiting & control equipment.
Type approval no. TÜV . WR/WB . XX-424
(see name plate)
Technical Data - continued -
Scope of supply
NRS 1-53
1 Level switch NRS 1-53
1 Installation manual

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1Upper terminal strip
2Lower terminal strip
Key
Installation in control cabinet
The level switch NRS 1-53 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
In control cabinet: Mounting level switch
Dimensions NRS 1-53
Fig. 1 2
74
1
4 3
46 120

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In control cabinet: Mounting level switch - continued -
Name plate / marking
Name plate (on top)
Name plate (at the bottom)
Type designation
Protection
Manufacturer
Output contacts
Fig. 2
Ambient temperature
External fuse for
output contacts
Material number
Supply voltage
Fuse, provided on site
Power consumption
Disposal note
Approvals
Connection of
level electrodes
Serial number
Safety note
Mat-Nr.: 392621
M 0,5A
24 V = +/- 20%
NRG 1.-.. ER 5.
2 VA
TÜV.WR/WB.xx-424
+
_
75
A
B
C
D
43 21
Folge - Typenschild
NRS 1-53
CorelDraw X3
Examiner
Designer
Drawer
Scale
Refer to protection notice ISO 16016!
Free size tolerance ISO 2768 mk 1:1
No Änderung/Modification Datum/Date Geänd/Modif. PrüferKonstr.
Datum/Date Name/Name
Nr./No
Ersatz für/Replaces Ersetzt durch/Replaced by
Ersteller/ Konstrukteur/ Prüfer/
Freimaßtoleranzen ISO 2768 mk
GESTRA
Schutzvermerk ISO 16016 beachten!
Maßstab/
Nr./ M-Nr.
- -
Laupichler
2012-03-21
2012-03-21 Paul
4-392704-01
42
01 TÜV-Nr.: die TÜV.WR/WB. 10-424 in 15-424 geändert 50000152O.HadréPaul2016-03-23

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In control cabinet: Wiring level switch
Wiring diagram for level switch NRS 1-53
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 2 electrode rod or MIN electrode rod
8MIN 1 electrode rod
9Central earthing point (CEP) in control cabinet
0MIN 1 output contact
aMIN 2 output contact
bWire link, provided on site if only one electrode rod is used
Key
Fig. 3 5
9
(–) (+) 7
M 0.5 A
(semi-
delay) 8
6
a 0
b
0a
M 0.5 A
(semi-
delay) 6
7
9
5
(–) (+)