Troubleshooting Loud Noises Coming From A Transfer Switch Connected To An Inverter And Shore Power

Published 11/04/2024

Question:

Hello, I just installed the F50-ATS in my rv for my 3k watt inverter. When shore power is hooked up the transfer switch makes a solid loud click. Now, if shore power is disconnected and I turn on the inverter on the inverter itself, the ATS makes a very loud and magnetizing sound to get it to switch. It scared me at first. With the inverter on I can plug in shore power and the ATS does switch back to shore. I tested the inverter on and ran my AC and TVs just fine. Slight humming noise at the transfer switch which I assume is normal for such a high current. My thoughts are when I turn on the inverter with the power button it’s generating enough power to switch the ATS over is why it’s making that loud magnetizing noise and same when I turn off the inverter like it’s winding down. Thank you for your time.

asked by: Andrew B

Expert Reply:

Hey Andrew,

A humming/buzzing noise can be an indication that the you either have a loose wire that's allowing for more resistance, too low gauge of wire used between the inverter and transfer switch, or you could have a faulty ground. Does it feel hot (temperature) on the inverter side of the wiring? I would doublecheck the inverter's manual to ensure that you used the right gauge wire, check for loose connections, and recheck that the ATS # 34264403 was properly grounded to the trailer frame.

Inverters will make noise but you really shouldn't be hearing that much at the transfer switch. In your setup the inverter likely can not read that you switched over to shore power and is still trying to send power to the transfer switch so you'll want to manually turn off the inverter right after switching to shore power.

In my experience, transfer switches do make a loud pop sound when switching between shore and inverter/generator power but nothing too crazy so I'm curious if yours is louder due to something else.

expert reply by: Kevin C

Andrew

11/4/2024

Thanks for the reply. It sounds like you can hear the current flowing through. Like standing near an electrical junction box. When I have both shore and inverter on it chooses shore correctly. When I simulate power loss at the campground it then switches to inverter normally and back to shore when plugged back in. What is weird is no shore connected and inverter off. If I turn inverter on the ATS sounds like it’s magnet charging and when it gets enough power it flips the switch. It does the same magnet noise when I turn off the inverter. Again, normal switch pop between the two when shore is hooked up. Does this sound correct with the electro magnets inside the ATS?

Kevin C.

11/4/2024

@Andrew That would not be normal. Go Power has some pretty good techs to call so I would try reaching out to them over the phone and recreating this so that they can hear the noise the ATS is making. I would also doublecheck the wiring like I stated above to ensure the gauge or connection is not causing the issue. I installed one of the # 34264403 two weeks ago for a friend and ran his new inverter to the generator side of this just like you did and did not hear anything besides the normal 'pop' when switching between shore and inverter power.