Restart Block - GE MOTOR MANAGEMENT RELAY 469 Instruction Manual

4.8 S7 MOTOR STARTING
S RESTART BLOCK
S [ENTER] for more
The Restart Block feature may be used to ensure that a certain amount of time passes between stopping a
motor and restarting that motor. This timer feature may be very useful for some process applications or motor
considerations. If a motor is on a down-hole pump, after the motor stops, the liquid may fall back down the pipe
and spin the rotor backwards. It would be very undesirable to start the motor at this time. In another scenario, a
motor may be driving a very high inertia load. Once the supply to the motor is disconnected, the rotor may con-
tinue to turn for a long period of time as it decelerates. The motor has now become a generator and applying
supply voltage out of phase may result in catastrophic failure.
The Restart Block feature is strictly a timer. The 469 does not sense rotor rotation.
4
NOTE
4-56
ð

RESTART BLOCK:

ENTER
Off
ESCAPE
RESTART BLOCK
ESCAPE
TIME: 1 s
MESSAGE
469 Motor Management Relay
4 SETPOINT PROGRAMMING
Range: On, Off
Range: 1 to 50000 sec., step 1
4.8.4 RESTART BLOCK
GE Power Management