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Phase Failure Relays

Class 8430-Type MP

The Class 8430 phase failure relays offer the reliability and accuracy of solid state circuitry with the isolation of hard output contacts.

Phase Loss: This condition occurs when one line of a 3 phase system is completely lost.

Phase Unbalance: This condition occurs when the voltage in one line of a 3 phase system drops below the voltage in the remaining two lines.

Phase Reversal: This condition occurs when two of three lines in a 3 phase system are switched. This incorrect connection will cause a motor to rotate in the reverse direction.

Undervoltage: This condition occurs when the voltage in all three lines of a 3 phase system drops simultaneously.

Class/Type	Protects Against				Description	Contact Arrangement	Nominal Voltage	Type	Price
	Phase Loss	Phase Unbalance	Phase Reversal	Under Voltage
8430 MPS	Yes	Yes	Yes	Yes	Phase Failure and Undervoltage Relay The Type MPS is a socket mounted, voltage sensing phase failure relay. The undervoltage setting is adjustable from 75% to 100% of normal voltage. The relay is UL Listed with the appropriate socket (see socket selection on page 21-19). The 240 V rated, SPDT output contacts change state upon phase failure, undervoltage, phase reversal or phase unbalance of 10% or greater. Response time delay is 3 seconds.	SPDT	240–60	MPSV24	$219.
							480–60	MPSV29
8430 MPD	Yes	Yes	Yes	Yes	Phase Failure and Undervoltage Relay The Type MPD offers the same protection as the Type MPS plus the following features: DPDT 600 V rated output contacts, locking potentiometer undervoltage adjustment and an LED indicating "relay energized." Can be mounted directly to a panel or to 8501 XM track (see page 21-7).	DPDT	120–60	MPDV20	488.
							240–60	MPDV24
							480–60	MPDV29
							600–60	MPDV32

General

MPS:		File E42240 CCN NLDX provided the proper socket is used. 8430MPSV24 - 8501 NR51 or NR52 socket (see page 21-19). 8430MPSV29 - 8501 NR82 socket (see page 21-19).
		File E42240 CCN NLDX2 without using the sockets listed above.
		File LR60905 -174
MPD:		File E42240 CCN NLDX

For Mounting Track for the 8430 MPS relays page 22-16

For additional information, reference Catalog #8430CT9701.