Three Phase Monitor Relay Comparison

Macromatic three-phase monitor relays detect phase and voltage faults that can affect motors and equipment. Also called phase protection or phase control relays, they are used in car wash facilities, elevators, packaging equipment, HVAC systems, irrigation and pump controls. Compare plug-in and DIN-rail models below to match the protection functions, settings and output contacts to your application.

Compare protection, mounting and output contacts

Click or tap on a series name to view products.

Series	Housing Type	Phase Reversal	Phase Loss	Phase Unbalance	Undervoltage	Overvoltage	Output	Approvals
PCP	Plug-in	Yes	No	No	No	No	SPDT 10 A	cURus, cULus (with socket), CE
PLP	Plug-in	Yes	Yes	No	No	No	SPDT 10 A	cURus, cULus (with socket), CE
PAP	Plug-in	Yes	Yes	No	Adjustable 75–95%	No	SPDT 10 A	cURus, cULus (with socket), CE
PJPU-FA8X	Plug-in	Yes	Yes	Indication only at 6%	Fixed at 90%	No	SPDT + SPNO 5 A	cURus, cULus (with socket), CE
PMP	Plug-in	Yes	Yes	Adjustable 2–10%	Adjustable 80–95%	Fixed at 110%	SPDT 10 A	cURus, cULus (with socket), CE
PMPU-FA8	Plug-in	Yes	Yes	Fixed at 6%	Fixed at 90%	Fixed at 110%	SPDT 10 A	cURus, cULus (with socket), CE
PMPU-FA8X	Plug-in	Yes	Yes	Fixed at 6%	Fixed at 90%	Fixed at 110%	SPDT + SPNO 5 A	cURus, cULus (with socket), CE
PMPU-FA12X	Plug-in	Yes	Yes	Fixed at 6%	Fixed at 90%	Fixed at 110%	DPDT 5 A	cURus, cULus (with socket), CE
PMD	DIN-rail	Yes	Yes	Adjustable 2–10%	Adjustable 80–95%	Fixed at 110%	DPDT 10 A	cULus, CE
PBDU	DIN-rail	Yes	Yes	Adjustable 5–25%	No	No	SPDT 5 A	cULus, CE
PC	DIN-rail / Modbus TCP	Yes	Yes	Adjustable 2–10%	Adjustable 80–95%	Adjustable 105–120%	SPDT 5 A	cULus

Understand the settings: Undervoltage and overvoltage percentages refer to the nominal or selected line-to-line voltage. Phase unbalance percentages describe the difference between phase voltages, not an undervoltage setting. PJPU-FA8X has phase unbalance indication only at 6%, it does not trip the relay.

Narrow your relay selection

Start with the faults you need to detect

PCP covers phase reversal, while PLP adds phase loss protection. PAP adds adjustable undervoltage detection. For phase reversal, phase loss, phase unbalance, undervoltage and overvoltage protection together, compare PMP, PMPU-FA8, PMPU-FA8X, PMPU-FA12X, PMD and PC.

Choose fixed or adjustable settings

The PMPU-FA8, PMPU-FA8X and PMPU-FA12X use fixed thresholds of 6% phase unbalance, 90% undervoltage and 110% overvoltage. PMP and PMD offer adjustable unbalance and undervoltage settings. PC also provides adjustable overvoltage protection from 105–120%.

Match the panel and control circuit

Choose a plug-in relay for socket mounting or a DIN-rail model for direct panel installation. Compare SPDT, SPDT + SPNO and DPDT contacts against your circuit requirements. The PC model linked above, PC1MDUL, combines DIN-rail mounting with Modbus TCP communication and a 5 A SPDT output.

Before ordering a phase monitor relay

Confirm the exact model supports your system voltage and required fault protection.
Match the output contact arrangement and rating to the control circuit.
Check trip delay, restart delay and reset behavior in the model documentation.
For plug-in models, select the compatible socket and verify any socket-dependent approvals.