Gestra NRS1-53 Level Switch

Data Sheet 819205-03 Issue Date: 09-2024
Level Switch
NRS 1-53
Description
Technical data
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.
Supply voltage 24 VDC, + / –20 %, 0.1 A
Function
NRS 1-53
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.
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