Power Converter WF-8955AN with Plastic

Converter

You mean "converter" not "inverter"

The converter gets 120v as input. You say the receptacles work, so first make sure the receptacle the converter is plugged into works too.

If not check the circuit breaker for that receptacle. It may be popped but not show it is. Snap back and forth.

The receptacles are often on a string with GFCI which usually goes when one of them gets wet. Like when you wash the RV and the outside receptacles get wet.

The converter has a 125v glass fuse inside it where its 120v cord comes it. You would have to take a few things apart to get at that.

On the 12v side, there are the two or so 30a (usually) fuses for 'reverse polarity' that could have blown. These may be on the converter itself or over on the DC fuse panel, don't know with that WFCO which it is.

Your RV may have a "battery disconnect switch" that may be open and not noticed. Easy with a push-pull type to happen.

Near the battery on the positive wire there will be a "battery fuse" or instead a DC circuit breaker. If it is a breaker it may have a little black reset button.

You need a new extension cord with #12 wire minimum.

Any chance it was an old cord with a weak connector?

Get it plugged back in and measure the DC voltage in the fuse panel. s/b 13.6 volts. Disconnect the negative battery cable for this test. Basically the converter is 120vac in, 13.6 vdc out or it is shot. Turn on the lights to load it up a bit. If it needs replacement there are much better converters for just a few dollars more.

If you have a portable charger go ahead and charge the battery and see how that goes. Battery might be shot and caused a heavy load on the converter and cord. Maybe just take it down to be tested.

Post what you find.

A sparking connection won't cause a surge in the RV, but a brownout and generally noisy AC. Generally speaking, I wouldn't expect that to fry the inverter or converter, though it's not completely beyond the realm of what's possible.

Is your inverter a charger/inverter, or do you have a separate converter/charger? Obviously whatever is supposed to be charging the batteries and working as a 12V converter isn't doing its job. Before just spending money to replace it, I'd do some basic troubleshooting first: is 120V AC power getting to it? Are all the connections and fuses on it good? Is there 12V output on its output terminals?

Have you checked that all the RV 120V circuit breakers and GFCIs are not tripped? Sometimes the converter/charger is on its own dedicated circuit.

Some smarter chargers don't like to charge a battery that's too run down. It may be necessary to connect a normal battery charger to the house battery for awhile (assuming it's undamaged from being discharged) and getting it up to a low charge before the converter unit will do its job properly.

I would also suggest checking that the RV 30A plug isn't getting overly warm. It may need to be replaced after the arcing next to it due to heat damage, even if such damage isn't immediately obvious externally. If it's staying reasonably cool (cool enough to touch when unplugged after having a moderate load for awhile, say), it's probably okay.

EDIT: The WF-8955 is a converter/power center, not an inverter. I don't think there's an inverter involved anywhere. (An inverter converts 12VDC to 120VAC, while a converter/charger converts 120VAC to 12VDC.)

The initial cord was probably too small. I did replace with a heavy duty cord. I also have the adapter off the ground and tapped up to avoid as much moisture. I'm leaning towards the fact that my inverter is fried...

The only thing that crosses my mind is what gauge wire was the extension cord from the RV30A to 15A adapter to the house/garage 120VAC 15/20AMP receptacle.

They should be 10 gauge (10-3) HD extension cords. You could get away with a 12-gauge size extension cord but no way any smaller gauge cords can be used especially if they are 50-foot long. The RED-ORANGE type cords from WALMART are probably 16 gauge size wire.

Once the smaller gauge cords get hot they start arcing over at the terminals and eventually melts the connectors.

To be sure the connections between the house and trailer are good one should check them by hand after a few minutes of using them to see if the connections are starting to get warm to hot.

I have two cables run across the yard all the time for my two RV trailers and I feel the connections everytime I am around them. I use two 50-foot contractor grade 10-gauge (10-3) Extension Cords. My RV30A-15A Adapter is from WALMART.

If you was using the smaller gauge cables that is most likely why they failed. I also do not allow my RV30A-15A Adapter to lay on the wet ground. I use a snap lid plastic box somewhat weather tight around this connection between the Shore Power cable and the Extension Cord coming from the House/Garage connection.

Just my thoughts
Roy Ken