Monitoring Relays

Monitoring relays are a type of relay that trips a circuit breaker when a fault is detected. A relay is an electrically controlled switch that is used to turn the power on or off in a circuit. 




Monitoring relays are more sophisticated than regular relays, as they have adjustable operating conditions, whereas normal relays switch according to a fixed threshold. They measure a given parameter, such as voltage or temperature, and will trip a circuit breaker when the parameter gets too high or low. 




What are monitoring relays used for?


Monitoring relays have a wide range of uses, depending largely on the factor being monitored. For example, they can protect against overcurrent if measuring current, or they can detect an abnormally low frequency if frequency is being measured.




Types of monitoring relay


The main way in which monitoring relays differ is the function that they measure. This can be a number of things, including:



  • voltage

  • current

  • temperature

  • frequency


The factor that you need to measure will decide which monitoring relay you choose.


...
Read more Read less

Filters

Viewing 1 - 20 of 57 products
Results per page
Description Price Monitoring Application Supply Voltage Contact Configuration Voltage Sensitivity Electrical Phase Voltage Sensing Range Current Sensitivity Minimum Current Sensed Maximum Current Sensed Phase Sensitivity Time Delay Temperature Sensitivity Temperature Sensing Range Frequency Sensing Range
RS Stock No. 850-5370
Mfr. Part No.LXPRT 280-520VAC
£51.52
Each
Units
Phase, Voltage 280 → 520 V ac SPDT Undervoltage - 300 → 500 V - - - Phase Failure, Phase Sequence 0.2 → 10 s - - -
RS Stock No. 850-5411
Mfr. Part No.LBVR/A 12-24VDC
£43.12
Each
Units
Voltage 8 → 30 V dc SPDT Undervoltage - 12 → 24 V dc - - - - 0 → 30 s - - -
RS Stock No. 629-386
Mfr. Part No.M3PPI 300-500vAC
£40.39
Each
Units
Phase 300 → 500 V ac - - 3 - - - - Phase Loss, Phase Sequence - - - -
RS Stock No. 850-5364
Mfr. Part No.LXPRC/S-4W 230V (400V)
£66.08
Each
Units
Phase, Voltage 230 V ac SPDT Overvoltage, Undervoltage - 173 → 218 (Under) V, 242 → 288 (Over) V - - - Phase Failure, Phase Sequence 0.2 → 10 s - - -
RS Stock No. 397-9218
Mfr. Part No.45PSR 400VAC
£74.99
Each
Units
Phase 400 V ac SPDT - 3 - - - - Phase Loss, Phase Sequence 200 ms - - -
RS Stock No. 850-5392
Mfr. Part No.LMCCR-10A 24-230VAC/DC
£75.95
Each
Units
Current 24 → 230 V ac/dc SPDT - - - Overcurrent, Undercurrent 0.2A 10A - 0.1 → 30 s - - -
RS Stock No. 397-9139
Mfr. Part No.45TCR 24/230VAC
£96.36
Each
Units
Temperature 24/230 V ac - - - - - - - - 200 ms - -50 → +300°C 0 → 100 °C, 0 → 50 °C, 100 → 200 °C, 200 → 300 °C, -50 → 50 °C
RS Stock No. 850-5382
Mfr. Part No.LXPRF 280-520VAC
£48.17
Each
Units
Phase, Voltage 280 → 520 V ac SPDT Undervoltage - Maximum of 520 V - - - Phase Failure 100 ms - - -
RS Stock No. 850-5405
Mfr. Part No.LMCVR-500V 24-230VAC/DC
£75.95
Each
Units
Voltage 24 → 230 V ac/dc SPDT Overvoltage, Undervoltage - 10 → 100 V, 2 → 20 V, 20 → 200 V, 5 → 50 V, 50 → 500 V - - - - 0.1 → 30 s - - -
RS Stock No. 298-9416
Mfr. Part No.45175 230VAC
£63.46
Each
Units
Speed 230 V ac SPDT - - - - - - - 0.5 → 30 min, 0.5 → 30 s - - -
RS Stock No. 850-5389
Mfr. Part No.LXPRT-4W 230V (400V)
£53.76
Each
Units
Phase, Voltage 230 V ac SPDT Undervoltage - Maximum of 300 V - - - Phase Failure, Phase Sequence 0.2 → 10 s - - -
RS Stock No. 397-9202
Mfr. Part No.45PUVR-4W 400VAC
£69.22
Each
Units
Phase, Voltage 400 V ac DPDT Undervoltage 3 Maximum of 400 V ac - - - Neutral Loss, Phase Loss 200 ms - - -
RS Stock No. 850-5360
Mfr. Part No.LXPRC/S 400V
£60.48
Each
Units
Phase, Voltage 400 V ac SPDT Overvoltage, Undervoltage - 300 → 380 (Under) V, 420 → 500 (Over) V - - - Phase Failure, Phase Sequence 0.2 → 10 s - - -
RS Stock No. 321-6826
Mfr. Part No.45200 110VAC
£57.68
Each
Units
Temperature 110 V ac SPDT - - - - - - - 50 ms Overtemperature - -
RS Stock No. 397-9145
Mfr. Part No.70POCR 400VAC
£146.50
Each
Units
Current 400 V ac DPDT - 3 - Overcurrent - 5A - 0.2 → 10 s - - -
RS Stock No. 397-9195
Mfr. Part No.45PUVR 400VAC
£69.22
Each
Units
Phase, Voltage 400 V ac DPDT Undervoltage 3 Maximum of 400 V ac - - - Phase Loss 200 ms - - -
RS Stock No. 298-9400
Mfr. Part No.45050 230VAC
£71.53
Each
Units
Voltage 230 V ac SPDT Overvoltage 1 0.5 → 10 V ac/dc, 3 → 60 V ac/dc, 30 → 600 V ac/dc - - - - 0.1 → 3 s - - -
RS Stock No. 321-6848
Mfr. Part No.45175 110VAC
£63.46
Each
Units
Speed 110 V ac SPDT - - - - - - - 0.5 → 30 min, 0.5 → 30 s - - -
RS Stock No. 850-5395
Mfr. Part No.LXCVR 230V
£47.04
Each
Units
Phase, Voltage 230 V ac SPDT Overvoltage, Undervoltage - 173 → 218 (Under) V, 242 → 288 (Over) V - - - Single Phase 0.2 → 10 s - - -
RS Stock No. 321-6810
Mfr. Part No.45PTR 400VAC
£78.45
Each
Units
Phase, Temperature 400 V ac DPST - 3 - - - - Phase Loss, Phase Sequence 15 ms Overtemperature - -