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CHAPTER 5: SETTINGS
5.8.4
Restart Block
RESTART
Note
469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL
PATH: SETTINGS
S7 MOTOR STARTING
[
MESSAGE
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 continue 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.
RESTART BLOCK
RESTART BLOCK:
Off
RESTART BLOCK
TIME: 1 s
Range: On, Off
Range: 1 to 50000 s in steps of 1
5–69
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