Automatic Transfer Operation - Generac Power Systems Automatic Standby Generator Owner's Manual

3.4 — Automatic Transfer Operation
To select automatic operation:
1. Make sure the transfer switch main contacts are set to their UTILITY position (loads connected to the utility power
source).
2. Be sure that normal UTILITY power source voltage is available to transfer switch terminal lugs N1 and N2.
3. Press the AUTO button on the Control Panel Interface.
4. Set the Main Circuit Breaker (Generator Disconnect) to its ON (Closed) position.
With these steps complete, the generator will start automatically when utility source voltage drops below a preset level. After the unit starts, loads
are transferred to the standby power source.
3.4.1— Automatic Sequence of Operation
3.4.1.1 — Utility Failure
With the generator set to AUTO, when the utility fails (below 65% of nominal) a 10 second (optionally programmable) line interrupt delay time is
started. If the utility is still gone when the timer expires, the engine will crank and start. Once started, a 5 second engine warm-up timer will be ini-
tiated. When the warm-up time expires, the controller will transfer the load to the generator. If the utility power is restored (above 75% nominal) at
any time from the initiation of the engine start until the generator is ready to accept load (5 second warm-up time has not elapsed), the controller
will complete the start cycle and run the generator through its normal cool down cycle, however, the load will remain on the utility source.
3.4.1.2 — Cranking
The system will control the cyclic cranking as follows:
• 8 kW unit - 5 cranking cycles as follows: 15 second crank, seven (7) second rest, followed by four (4) additional cycles of seven (7) second
cranks followed by seven (7) second rests.
• 11 - 22 kW units - 5 cranking cycles as follows: 16 second crank, seven (7) second rest, 16 second crank, seven (7) second rest, followed by
three (3) additional cycles of seven (7) second cranks followed by seven (7) second rests.
3.4.1.3 — Load Transfer
The transfer of load when the generator is running is dependent upon the operating mode:
MANUAL •
•
•
AUTO •
•
•
•
•
EXERCISE
•
•
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Will not transfer to generator if utility is present.
Will transfer to generator if utility fails (below 65% of nominal for 10 consecutive seconds).
Will transfer back when utility returns for 15 consecutive seconds. The engine will continue to run
until removed from the MANUAL mode.
Will start and run if utility fails for 10 consecutive seconds (factory default).
Will start a 5 second engine warm-up timer.
•Will not transfer if utility subsequently returns.
•Will transfer to generator if utility is not present.
Will transfer back to utility once utility returns (above 75% of nominal) for 15 seconds.
Will not transfer back to utility unless utility returns. The generator will shut down if the OFF button is
pressed or a shutdown alarm is present.
Once utility power is returned, the generator will shut down after 1 minute cool-down time.
Will not exercise if generator is already running in either AUTO or MANUAL mode.
During exercise, the controller will only transfer if utility fails during exercise for 10 seconds, and will
switch to AUTO.
Automatic Standby Generator Owner's Manual