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RVing message boards => Trailers & Fifthwheels => Topic started by: Alwayslost on September 23, 2017, 05:40:51 AM

Title: Inverter trips plugged into shore power, works on my portable generator.
Post by: Alwayslost on September 23, 2017, 05:40:51 AM
I sure hope someone here can help! I've read through a few posts but still found no answer.
 So if I plug into shore power, either the breaker on the pole trips, or the breaker in my box trips. No matter the amperage. But if I use my generator, everything works ad it should. Electrical work is out of my wheel house, and I'm completely lost on this. If someone else has had this problem, and found the solution I'd love some input.
Thank you
Title: Re: Inverter trips plugged into shore power, works on my portable generator.
Post by: Alfa38User on September 23, 2017, 09:48:27 AM
Welcome!!

I think many here would recommend that you flip the main breaker(s) off both in the trailer and on the pole before plugging anything in. Then, put them back on one at a time once fully plugged in. What happens when you try that??  Doing so will prevent any arcing at those usually well worn plugs often found on park pedestals. (Another example: you may have left an air conditioner (a heavy load) on  by accident last time you unplugged). If this has happened often, you might might be better off changing out that circuit breaker in the trailer for a new one as they get weaker each time they blow.

Generator ATS's or output controllers usually have a built-in short delay before kicking in to allow the genny to come up to speed and produce the proper voltage and frequency. When a good surge protector is used, (highly recommended)  the same thing happens in order to check the incoming power.
Title: Re: Inverter trips plugged into shore power, works on my portable generator.
Post by: Roy M on September 23, 2017, 10:25:09 AM
Are you plugging into a GFCI outlet? If the inverter is similarly protected this will happen.
Title: Re: Inverter trips plugged into shore power, works on my portable generator.
Post by: Gary RV_Wizard on September 23, 2017, 10:39:40 AM
There aren't many things different for genset vs shore, but they can be obscure. The lack of a earth ground on a portable genset is one and that can affect GFCI trips. And if you have an onboard genset (most motorhomes), there can be problems in the auto-transfer switch (ATS) or manual plug.

Please tell us more about the rig and the problem details. Is the breaker tripping (current overload) or is it a GFCI fault? 30A or 50A shore power? Any adapter in use on the shore cord, e.g. a 30A-->15A adapter?   Built in genset or external portable? Have you plugged to more than one shore power outlet, to see if problem remains consistent?

Also, the title says the Inverter trips, but the body of the message says a breaker on the shore pole trips or a breaker on some [unidentified] box. How is the "inverter" involved?
Title: Re: Inverter trips plugged into shore power, works on my portable generator.
Post by: Lynx0849 on September 23, 2017, 02:23:57 PM
There aren't many things different for genset vs shore, but they can be obscure. The lack of a earth ground on a portable genset is one and that can affect GFCI trips. And if you have an onboard genset (most motorhomes), there can be problems in the auto-transfer switch (ATS) or manual plug.

Please tell us more about the rig and the problem details. Is the breaker tripping (current overload) or is it a GFCI fault? 30A or 50A shore power? Any adapter in use on the shore cord, e.g. a 30A-->15A adapter?   Built in genset or external portable? Have you plugged to more than one shore power outlet, to see if problem remains consistent?

Also, the title says the Inverter trips, but the body of the message says a breaker on the shore pole trips or a breaker on some [unidentified] box. How is the "inverter" involved?

A GFCI does not need a ground to operate. It simply measures the difference in current of the hot lead and the neutral lead. If different (for what ever reason) by 5ma, it trips. Note that GFCI breakers in a panel have no ground connection to them.
Title: Re: Inverter trips plugged into shore power, works on my portable generator.
Post by: Gary RV_Wizard on September 24, 2017, 09:36:33 AM
Quote
A GFCI does not need a ground to operate.

True, but that wasn't the reason for what I stated. A short to the chassis or to a ground wire won't cause a current imbalance if there is no path to an external electrical ground. A classic example is a neutral wire shorted to a ground wire in a branch circuit. If the ground wire has no path outside the RV, all the current still flows through the neutral and the GFCI will not detect a fault. The GFCI doesn't trip until someone or something closes the circuit between the ground or chassis and some external ground.