Comparison Between New & Old PMD Series Three-Phase Monitor Relays

Wednesday: May 27, 2015 : Three-Phase Monitor Relays

In May 2015, Macromatic introduced the next generation of PMD Series Three-Phase Monitor Relays. Many important features were added to the new products. These improvements along with a comparison to the previous design are summarized below:

  Current PMD Series PMD Series
Mounting Configuration 35mm DIN-Rail & Panel-Mounting 35mm DIN-Rail Only
Dimensions 45mm W x 114mm H x 70mm L 52.5mm W x 57mm H x 89mm L
Line-Line Voltage Range 200-480V (PMDU) 190-500V (PMDU)
575V (PMD600) 480-600V (PMD575)
120V (PMD120) 102-138V (PMD120)
Line-Line Voltage Dial (PMDU) 1 Scale
2 Scales
Low Voltage: 190-250V
High Voltage: 380-500V

Unit auto senses the three-phase line-line voltage when applied & automatically selects the appropriate voltage
Adjusting Line-Line Voltage Setting Can only be made with voltage
removed–changes in setting are ignored with power applied–must remove power before a change in a setting can be recognized
Can be made with voltage applied–any changes in settings with power applied will be immediately recognized
LED Fault Codes

3-Color LED


Printed on side of Product

Bi-Color LED

Printed on top of Product for Easier Visibility (see Picture above)

Operation with Lost Phase

Internal logic & LED were powered from two of monitored three phases. If either of these phases is lost, unit loses power, resulting in:

  • LED is OFF–no indication of phase loss condition
  • Unit is not continuing to monitor all three phases until lost phase is restored

No matter which of the three phases is lost, the new PMDU remains powered:

  • Retains fault indication of lost phase
  • Continues to monitor all three phases
Disable Phase Unbalance Unbalance Knob had "Disable" setting to remove unbalance protection Does not have "Disable" setting on Unbalance Knob–it was determined that removing Unbalance protection reduced the level of phase loss protection
Contact Configuration SPDT & SPNC DPDT
Increased Contact Ratings 10A @ 240VAC
No DC ratings
1/3hp @ 120/240VAC (N.O.)/
1/6hp @ 120/240VAC (N.C.)
No pilot duty
10 A @ 277VAC/
10A @ 30VDC
1/2hp @ 120/240VAC (N.O.)/
1/3hp @ 120/240VAC (N.C.)
C300 pilot duty

To learn more about our new line of PMD Series Three-Phase Monitor Relays, please click here: ProtectMyMotor.

If you still have questions about any differences between the new & old designs, please contact Macromatic Technical Support at 800-238-7474.

©2020 Macromatic Industrial Controls, Inc.

W134N5345 Campbell Drive
Menomonee Falls, WI 53051

800-238-7474 • 262-781-3366

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