Macromatic PMPU Phase Monitor Relay Competitive Comparison

THREE-PHASE MOTOR PROTECTION

Macromatic PMPU Phase Monitor Relay Comparison

Compare the Macromatic PMPU with Symcom 201A-AU, SSAC PLMU11 and Diversified SLU-100-ASA relays. Review voltage coverage, reset options and output ratings to choose a three-phase monitor for your control panel.

The Macromatic PMPU monitors three-phase power for phase loss, phase reversal, voltage unbalance, undervoltage and overvoltage. Its adjustable undervoltage threshold helps match protection to equipment requirements, while an external manual-reset option lets operators acknowledge a cleared fault before the relay resets.

190–500V ACNominal voltage coverageTwo setting scales: 190–250V and 380–500V.
80–95%Adjustable undervoltage tripPercentage of the selected line voltage.
External resetOperator-controlled resetOptional normally closed momentary switch.

Phase Monitor Relay Feature Comparison

Line-to-line voltage range

Macromatic PMPU
190–500V AC
Symcom 201A-AU
190–480V AC
SSAC PLMU11
200–480V AC
Diversified SLU-100-ASA
208–500V AC

120V and 575V family options

Macromatic PMPU
Yes: separate PMP120 and PMP575 models
Symcom 201A-AU
575V option only
SSAC PLMU11
No
Diversified SLU-100-ASA
No

Adjustable undervoltage trip

Macromatic PMPU
Yes: 80–95% of the line-voltage setting
Symcom 201A-AU
No: fixed at 90%
SSAC PLMU11
No: 88–92% trip point
Diversified SLU-100-ASA
No: fixed at 90%

Monitoring and indication after phase loss

Macromatic PMPU
Maintains voltage monitoring and fault indication
Symcom 201A-AU
Not fully maintained; LED may turn off
SSAC PLMU11
Not fully maintained; LED may turn off
Diversified SLU-100-ASA
Not fully maintained; LED may turn off

External manual reset

Macromatic PMPU
Yes: external switch option
Symcom 201A-AU
No external option; onboard reset only
SSAC PLMU11
No, has automatic reset
Diversified SLU-100-ASA
No external option; onboard reset only

Fault indication

Macromatic PMPU
Fault-specific bi-color LED
Symcom 201A-AU
Full fault indication
SSAC PLMU11
Partial: status and phase-reversal indication
Diversified SLU-100-ASA
No full fault indication

Output contact ratings

Macromatic PMPU
10A at 277V AC
7A at 30V DC
1 hp at 250V AC
½ hp at 125V AC
C300 pilot duty
Symcom 201A-AU
10A general purpose at 240V AC
DC rating: not listed
Horsepower rating: not listed
B300 pilot duty
SSAC PLMU11
10A resistive at 240V AC
DC rating: not listed
⅓ hp at 250V AC
¼ hp at 125V AC
Pilot duty: not listed
Diversified SLU-100-ASA
10A resistive at 240V AC
DC rating: not listed
½ hp at 240V
Pilot duty: not listed

RoHS status

Symcom 201A-AU
Compliant with exemptions
SSAC PLMU11
Yes
Diversified SLU-100-ASA
No

Separate voltage models are not additional voltage settings on the standard PMPU. Check the exact part number and current documentation before specifying a replacement.

What the PMPU Adjustments Do

Undervoltage: 80–95%

Select the low-voltage trip point to suit the equipment. For example, a 90% setting on a 480V system equals a 432V undervoltage threshold.

Trip delay: 0.3–30 seconds

Adjust the delay for undervoltage, overvoltage and unbalance faults. Phase loss and reversal use a separate, fixed 100 ms response.

Restart: 1–300 seconds

In automatic-reset mode, delay re-energization after a fault clears. Manual-reset mode requires the external reset switch and does not use this delay.

Before Replacing a Three-Phase Monitor Relay

  • Match the voltage and frequency. Confirm that the exact model and setting scale cover your system.
  • Check the socket and wiring. PMPU uses an 8-pin octal socket; applications above 300V require a 600V-rated socket.
  • Match the output load. Compare AC, DC, horsepower and pilot-duty ratings separately. A 10A rating alone does not establish equivalence.
  • Choose the reset behavior. Confirm whether the application needs automatic reset or an external manual-reset switch.

PMPU Phase Monitor Questions

Does PMPU continue monitoring after a phase is lost?

Yes. PMPU retains fault indication and continues voltage monitoring with a lost phase. This describes the monitor’s operation, not permission for the motor to keep running under a phase-loss condition.

Can PMPU replace a competing phase monitor?

PMPU is a replacement candidate when its voltage coverage, protection functions and output ratings fit the application. Confirm socket pin assignments and reset wiring before treating any model as interchangeable.

Find the Right Phase Monitor Relay

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