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> Relays / Timers > Phase Monitoring Relays

Phase Monitoring Relays

Phase monitoring relays protect against equipment failure caused by faults in three-phase systems, such as phase reversal, phase loss, phase unbalance, overvoltage, and undervoltage. These relays are compatible with Delta or Wye systems and are available in a range of voltage inputs.

Electro-Mechanical Relays

Optocoupler Relays

Solid State Relays

Phase Monitoring Relays

Voltage Monitoring Relays

Alternating Relays

Pump Seal Failure Relays

Intrinsically Safe Relays

Timer Relays

Multi-Function Digital Counter / Timer / Tachometer

Relay & Timer Sockets

Relay & Timer Accessories

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Phase Monitoring Relays

Dold and ProSense brand phase monitoring relays protect equipment from failure caused by phase/voltage faults including undervoltage, phase unbalance, and phase loss in three-phase AC systems. Select models provide voltage and neutral monitoring options for single-phase applications.

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ProSense PMR Series

ProSense phase monitoring relays protect three-phase systems from voltage and phase anomalies, are compatible with Wye or Delta systems, and are available in a range of voltage inputs.

10A contact rating
Up to 600 VAC input voltage
PMRU-TL series relays protect against phase loss, phase reversal, phase unbalance, undervoltage, and overvoltage for 3-phase systems from 190 VAC to 500 VAC
PMRR-TL series relays provide phase reversal protection in a compact low-cost design; one relay will work on any 3-phase system from 190 VAC to 500 VAC
PMRRL-TL series relays provide phase loss, phase reversal, and undervoltage protection for 208, 240, and 480 VAC systems
PMRU-2C series true RMS relays protect against phase loss, phase reversal, phase unbalance, undervoltage, and overvoltage in most generator and other applications from 190 VAC to 600 VAC and with non-sinusoidal waveforms
DIN rail mount or plug-in socket mount (sold separately), depending on model

Components starting at
$47.50
(PMRR-1C-480A-TL)

Dold VARIMETER Series

New!

Dold VARIMETER series phase monitoring relays provide early detection of phase unbalance, phase reversal, phase loss, overvoltage, undervoltage, and missing or broken neutrals in AC systems. They offer wide voltage measuring ranges, compact frame sizes, and integrated terminal bases. Simple single-turn switches allow quick and easy configuration without a complex menu structure.

80-230 VAC or 175-525 VAC measuring range
Single- or three-phase AC voltage monitoring
5A SPDT output contacts
Voltage, hysteresis, time delay, or monitoring function configuration options (depending on model)
Select models offer enhanced phase loss monitoring
Fast fault detection
DIN rail mounting

Starting at
$110.00
(RN9877-1203P4W525V)

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