701 Motor Protection Relay Date Code 20010719
SEL
OGIC
®
Control Equations & Relay Logic
Start and Emergency Restart Logic
B.24
In an emergency, it may be necessary to quickly start the motor even though a
protection lockout condition exists and is holding the TRIP output contact asserted.
The lockout might be a result of the thermal element or another protection function
(see Stop/Trip Logic on page B.19). You can override all the lockout conditions using
the Emergency Restart function.
The relay asserts the Emergency Restart Relay Word bit (EMRSTR) in response
to any of these conditions:
The EMRSTR Control Equation result is true (logical 1).
You execute the front-panel menu Emergency Restart command.
The relay receives a Modbus Emergency Restart control command.
When the Emergency Restart Relay Word bit asserts, the relay:
Resets the motor thermal element capacity used to 0%.
Manipulates the Starts-Per-Hour, Minimum Time Between Starts,
and Antibackspin functions to permit an immediate start.
Deasserts the TRIP output contact if no fault detecting element is
picked up.
Initiates a motor start through the logic shown in Figure B.7 on
page B.23.
NOTE: For the EMRSTR SELOGIC control equation performance
to match the performance of the front-panel and Modbus
Emergency Restart functions, you should include * STOPPED
in the SEL
OGIC control equation, as shown in Factory Default
Logic Settings on page B.13. Do not set EMRSTR =1.
Program an Output Contact for Motor Starting
In the factory settings, the result of the start logic in Figure B.7 is routed to output
contact OUT3 with the following SEL
OGIC control equation:
Equation B.5OUT3 START=
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