Just started up my Generac Natural Gas generator for the first time today.
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 position.
This happened both times I tested.
Any input as to what would prevent the switch from switching back to utility?
Have you asked Generac's tech support department? Seems to me that's the first place you should check...
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.
I think Pete has it right -- from Generac site on spec's for one of their automatic transfer switches -- I suspect if you look carefully, the unit you have will describe how it is set up or how to modify it. Although I suppose w/ a package unit they could have set it up w/ a fixed time delay to avoid user interference.
... Line Interrupt .........................................................................
0.1-10 Sec. (Adj.) Engine Minimum Run ................................................................ 5-30 Min. (Adj.) Engine Warmup ................................................................... 5 Sec.-3 Min. (Adj.) Return to Utility ........................................................................ 1-30 Min. (Adj.) ...
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. Bob
The Generac unit I have (7.5KWLiquid Propane/6.5KW NaturalGas) switches back to utility power in less than a minute. I am guessing it takes 30 to 45 seconds.
Smarty
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 can occur. 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- ing. . The timer will run for about one minute, and the generator will then shut down.
Smarty
The diagnostics and repair manual is at:
I would suggest you get a local Generac person to trouble shoot it. It is under warranty and the problem looks like it could be the logic board, coil, etc. Since the unit is brand new, let them fix it !!
Smarty
Tested two ways...turning off the 70 amp breaker that powers the transfer switch and the second time turning off the main breaker.
What I observed (before opening the transfer case and seeing the switch still in the generator mode) was that the unit was running in cool down mode, observed that the basement circuits seemed to be getting some sort of "trickle" power (lights were dimmed, battery back up sump pump was running but the two AC pumps also seemed to be running (but dry, not moving any water).
We were told the switch should go back to utility within 30 seconds once utility power is detected again. It doesn't make sense if it takes 10 or more minutes then our lights/appliances are not going to have any power until the transfer switch pops back to utility mode.
Reasonable ways to test.
If you have any sort of "half powered" condition like this it indicates a serious problem. Get it checked by a competent person ASAP or sooner. With a properly wired and functioning transfer switch all circuits only have three possible states, powered properly from utility, powered properly from the generator or unpowered if the selected source is not available.
Someone else posted info from the manual indicating a 15 second utility stabilization delay followed by a one minute generator cool down delay. The big transfer switches typically have longer delays like the 10 min retransfer I mentioned and longer generator cool down.
The switch did not move back to utility even after the cool down was over and the generator shut down.....waited another 5 minutes and still no switch. In the meantime, the sump pumps were without power....definitely does not seem correct.
The manual I sent handles Generac models up to 16KW. I assume you are referring to huge models when you refer to such long transfer times. The longer delay times are intended to prevent intermittent utility power to cause the generator to toggle / transfer the load back and forth unnecessarily.
Smarty
Mine is a 16kW model
Problem found and solved by the electrician!
Turns out that there was a wire, in the generator control panel, pinched under the grounding screw.
Works perfectly now.
Michael, I'm glad to see that you didn't need / use the Generac maintenance manual link I sent previously to you. Also glad your problem is solved. Good luck with your new Generac. Mine works beautifully and I hope yours does as well.
Smarty
Thanks for the help!
Glad to help you Michael.
Smarty
replying to mikegold, Mark14103 wrote: I bought a 10 kw whole house transfer switch and with utility power on. The generator won't shut done it says no power detected. Checked wiring and everything is properly done any suggestions?
Two choices. If you have the skills, get a schematic and start diagnosing. If not, call a pro. For what it's worth, from what I saw with a neighbor's system and from reading reviews on Amazon, I wouldn't put any money into a Generac home system.
replying to trader_4, Mark14103 wrote: Ichecked the wires going to n1 and n2 both are good rang them out but put fuse in n2 and blew again something wrong on generator side guess I will call dealer to fix problem any other suggestions?
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