From page 18 of the Owner and Installation Mnaual, it looks like 15 seconds
is the delay after utility power is restored until the automatic transfer
switch is restored to the utility position. See Step E below - retransfer:
A. Utility Voltage Dropout Sensor
. This sensor monitors utility source voltage.
. If utility source voltage drops below about 65
percent of the nominal supply voltage, the sensor
energizes a 10 second timer.
. Once the timer has expired, the engine will crank
and start if utility is still low.
B. Engine Warm-up Time Delay
. This mechanism lets the engine warm up for
about five (5) seconds before the load is trans-
ferred to the standby source.
C. Standby Voltage Sensor
. This sensor monitors generator AC output volt-
age. When the voltage has reached 50 percent of
the nominal rated voltage, transfer to standby
D. Utility Voltage Pickup Sensor
. This sensor monitors utility power supply volt-
age. When that voltage is restored above 75 per-
cent of the nominal source voltage, a retransfer
time delay starts timing.
E. Retransfer Time Delay
. This timer runs for about 15 seconds.
. At end of a 15-second delay, circuit board action
de-energizes transfer relay in the transfer switch
if utility is still present.
. Retransfer to utility power source then occurs.
F. Engine Cool-down Timer
. When the load is transferred back to utility power
source, the engine cool-down timer starts tim-
. The timer will run for about one minute, and the
generator will then shut down.
Post by Bob
Post by Pete C. Post by mikegold
Just started up my Generac Natural Gas generator for the first time
Transfer switch automatically switched over to generator power as
expected however, when I turned utility power back on the switch did
not transfer back to utility.
I had to open the switch and manually transfer back to the utility
This happened both times I tested.
Any input as to what would prevent the switch from switching back to
How did you test, by turning off the main utility breaker? How long did
you wait after turning utility power back on? Most transfer switches
have timers and won't transfer back to utility for about 10 minutes
after it comes back to insure it is stable.- Hide quoted text -
- Show quoted text -
That's the way the big units work, transfer switch transfers 10-15
minutes after commercial power is restored, then has about a 3-5 min
generator run without power for a "cooldown" before final shutdown.