Three-Phase Monitor Relays

Three-Phase Monitor Relays

Three-Phase Monitor Relays continuously monitor and detect voltage faults to protect equipment in three-phase systems. These relays retain indication and continue monitoring even with a lost phase. True RMS voltage measurement ensures more accurate sensing across more applications.

Protect Equipment Against Premature Failure

Three-Phase Monitor Relays are available with plug-in or Din-rail enclosures that offer protection from a combination of voltage faults: Phase Loss, Phase Reversal, Phase Unbalance, Under Voltage, or Over Voltage. These relays are compatible with most Wye or Delta systems with no connection to neutral required.

PCPU plug-in product


PAP, PCP, PLP and PMP Series with plug-in enclosures use standard 8 pin octal sockets. These relays have a wide universal voltage range for use in more global applications.


PBDU Series (17.5 mm wide) and PMD Series (52.5 mm wide) mount on 35 mm DIN-rail. Both can be panel mounted with two screws by extending the black clips from under the relays. Full fault indication on top of units facilitates easy troubleshooting.

product on white


Relays protect and communicate fault conditions with Modbus TCP to reduce downtime and service costs. These relays improve decision making within smart control systems. Real-time and historical data is available for alerts, predictive maintenance, and troubleshooting.

  • Communication Platform: Modbus TCP
  • Monitored Voltage: 190-600V AC
  • Output: 5A SPDT
  • Protection: Phase Loss, Phase Reversal, Voltage Unbalance, Undervoltage & Overvoltage
  • Standard Modifications: Local Adjustment (PC1MDUL);
  • Enclosure Style: DIN-Rail

Frequently Asked Questions About Three-Phase Monitor Relays

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