Comparison Between New & Old PMD Series 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 208-480V  |
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:
|
No matter which of the three phases is lost, the new PMDU remains powered:
|
| 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.
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Three-Phase Monitor Relays