LEVEL SWITCH GESTRA NRS 1-53

Level Switch
NRS 1-53

Technical data
Supply voltage
24 VDC, + / –20 %, 0.1 A
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.
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 adjusters
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.
Terminal strips separately detachable.
Fixing of enclosure: Mounting clip on supporting rail TH 35,
EN 60715
Electrical safety
Contamination class 2.
Protection
Housing: IP 40 to EN 60529
Terminal strip: IP 20 to EN 60529
Weight
Approx. 0.2 kg
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

Description
The level switch NRS 1-53 in conjunction with level electrodes
NRG 16-.. and ER 5. is used as limit switch, for instance as
water level limiter in steam boilers and (pressurized) hot-water
installations. The level switch detects and indicates two low
water levels (MIN 1, MIN 2).
The level switch can work with following level electrodes:
NRG 10-52, NRG 16-52, NRG 16-4 and ER 5.-1.
Function
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.
The length of the associated electrode rod determines switchpoints for MIN 1/MIN 2 water level.
The level switch detects that the MIN1/MIN 2 water level is
reached when the corresponding electrode rods are exposed.
After the de-energizing delay has elapsed, the MIN 1/MIN 2
output contact is switched over. At the same time the MIN
1/MIN 2 LED changes 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.
A MIN 1/MIN 2 alarm can be simulated by pressing the
button “Test”.
Application in potentially explosive
atmospheres
Do not use the equipment in potentially explosive atmospheres