LPRC/2/WS Three Phase Voltage Monitoring Relay

  • Under and Over voltage monitoring (Window)
  • Selectable nominals for popular 3-wire or 4-wire supply voltages
  • Detects incorrect phase sequence, phase and neutral loss
  • Adjustable Trip levels and Time delay
  • DPDT Relay output
  • 17.5mm wide, DIN Rail mount
  • UL Listed

The product monitors it’s own three-phase supply and can be set for either 3-wire or 4-wire monitoring. For the relay to energise, all phases (and neutral if applicable) must be present, phase sequence correct and the measured voltages within the set under and overvoltage trip levels. If any of these conditions are not met, the relay will  remain de-energised.

  • Monitoring function: Under/Over voltage
  • Monitored supply voltages:
    • 3-wire: 380V, 400V or 415VAC
    • 4-wire: 220V, 230V or 240VAC
  • Trip level: Under: 75 – 95%/Over: 105 – 125%
  • Hysteresis: ≈2%
  • Time delay: 0.2 – 10s
  • Output: DPDT 5A @ 250V (AC1)
  • Dimensions(mm): W:17.5 x H:89 x D:66.5

(Order Code: 99-4206)

Distributors Stock Code Link
Farnell 4825129 Go to product

Typical applications include:

  • Motor control centres
  • Water-treatment installations
  • Lift and elevator control panels
  • OEM machine building and control panels

Key benefits:

  • Helps protect against unsuitable supply voltage — Under and over voltage monitoring allows an external control circuit to inhibit equipment when the measured supply leaves the set voltage window.
  • Helps prevent incorrect motor rotation — The relay requires correct phase sequence before energising, allowing a motor contactor to be inhibited when the incoming phases are reversed.
  • Responds to phase and neutral faults — Phase-loss detection and neutral-loss detection in the supported four-wire arrangement can release the control permissive when the incoming supply is incomplete.
  • Helps avoid unnecessary voltage-fault trips — An adjustable fault delay allows brief voltage deviations to be tolerated before the relay changes state, subject to the documented immediate-trip conditions.

Alternative product:

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LPRC/2/W Three Phase Under/Over Voltage Monitoring Relay
  • Under and Over voltage monitoring (Window)
  • Selectable nominals voltages
  • Detects phase and neutral loss
  • Operates irrespective of phase sequence
  • Adjustable Trip levels and Time delay
  • DPDT Relay output
  • 17.5mm wide, DIN Rail mount
  • UL Listed
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