Class 8430 Type MPD
The Class 8430 Type MPD phase failure relay is a three-phase voltage sensing device that trips on phase loss, phase reversal, voltage unbalance, or undervoltage. Voltage unbalance trips the device when any voltage drops
10% below the average. Undervoltage is externally adjustable from 75–100% of the rated voltage. The LED on the front of the device lights when the device is energized. Two 600 V Form C output contacts are standard on all devices.

Class 8430 Type MPS
The Class 8430 Type MPS phase failure relay is a three-phase voltage sensing device that trips on phase loss, phase reversal, voltage unbalance, or undervoltage. A voltage unbalance trips the device when any voltage drops 10% below the average. Undervoltage is externally adjustable from 75 to 100% of the rated voltage