How to check inverter

[TLLOYD]

I have a Xantrex Pro XM1800 inverter on my 2016 RV. After the just over a year of FINALLY getting all of the issues fixed during the first year and a half with the help of Thor I have since ran into an issue with the inverter.

I have two 6 volt batteries both showing above 6.5 volts. I have checked the volts to the inverter and it is above 13 volts.

When I turn the inverter on it just flashes on the panel. Sometimes 13.5, sometimes OL and the inverter itself located in the rear outside cabinet "clicks" like a heartbeat. I guess like it wants to come on but doesn't. The lights in the RV dim in and out also and the refrigerator does the same. I have noticed the inverter itself gets hot to the touch.

I turn everything off (lights and refrigerator) and it still does the same thing.

I can check the load in as the power cables from the batteries are exposed where they hook up to the inverter. I read to check the load out, but can't figure out how to do this.

I basically have to run the generator when traveling to keep the refrigerator cold until I hook up to shore power.

[MEXICOWANDERER]

Needed
Small tool kit screwdrivers
Tour smart phone camera

• Unplug unit from shore power
• Remove negative cables from batteries, chassis and house. TAKE IMAGES WITH CAMERA before touching anything
• Inverter is playing dead even when you poke it
• Look for place where smaller AC wires go through a plate on the back
• Turn inverter up and around so you can work with it easiest
• Remove wire clamp and plate
• TAKE IMAGES WITH CAMERA of screws and wire colors inside hole where plate was removed
• Are the wires labelled? Hot or L Neutral? Ground?
• Are there more than THREE 120vac wires inside connecting to screw terminals? Wrap one bundle with electrical tape for an ID then take another picture
• Does the terminal block have a label LOAD? Those are the wires you want to remove, fold back then tape........................Time to test. Reconnect the load wires
• If unit has two sets of AC wires. TAPE THEM BOTH UP
• Reconnect battery
• Turn inverter on
• Does it still overheat? If yes, it goes to the recycling center.

[time2roll]

TLLOYD wrote:
....the output wiring is hard wired directly into the inverter so kind of confused on how to just unplug it.

Open the access panel and loosen the three screws.

[TLLOYD]

No nothing out of the ordinary was plugged in (heater or anything).
There is a small reset button on the bottom of the inverter, but that is not tripped.

The only thing that was maybe a bit unusually now that I am thinking about it is I had some family staying in the RV while it was plugged into my house (shore power) and my house breaker kicked off when both RV air conditioners were turned on at the same time. I reset the breaker on the house and everything was fine.

Don't know if this could have done anything to the inverter and would imagine it couldn't.

[MrWizard]

your inverter has 'pass thru' TS switch

your hard wired to the circuit that use it
most likely a circuit breaker in the panel provides up to 15a of pass thru power

unless there is a reset circuit breaker on the inverter, that is tripped
the TS has failed, or the inverter function has failed

you didn't happen to use that circuit to power an electric heater did you ?
sometimes that kind of sustained load will damage the TS relay circuit
overheating the contacts

[TLLOYD]

Easy enough to disconnect the input power from the batteries, but the output wiring is hard wired directly into the inverter so kind of confused on how to just unplug it.

[time2roll]

With a factory install I assume nothing extra is getting powered by the inverter. If wiring was repaired by the dealer something may have gotten crossed up or in a rare case a screw driven through a wire that was behind something.

Otherwise time to remove and bench test but I am guessing the inverter is shot. Failed way too soon 😞

[MEXICOWANDERER]

No load means the unit is disconnected from AC power to the rig. Physical unplugging of the inverter at the inverter not the breakers. Does it still click and stew in it's own juices? One step at a time...

[TLLOYD]

Never had an inverter in my past toy haulers so new to this.

I purchased the RV brand new so it was factory installed. The only thing I had added was solar panel as the dealer said the batteries aren't really sufficient.

Not a great walk through when I purchased RV and I had asked about the inverter. I believe they said it ran the refrigerator and maybe the TV's only, but the guy who did the walk through was not really that informative.

I have had numerous issues with this RV (Slide out, major water leaks, generator and more). The batteries were replaced last year during warranty service as they kept saying I must have battery issues with some of the problems I was having.

The inverter did work to run the refrigerator up until my last trip out.

I have turned off all breakers and still doing the same thing.

I contacted Thor and they thought it may be a battery issue. I am waiting on a reply after letting them know the battery voltage was good and power to the inverter was good. I will also let them know the latest things I have tried with forum help and see what they say.

Hoping they will honor a promise they gave me to extend my warranty by a year since it took them so long to fix all of the initial issues.

I just hope there isn't an issue with the electrical system that I will have to deal with for quite some time.

[MrWizard]

is this hard wired for the fridge only
or
is whole house ?

if whole house, turn off the water heater, turn off the converter
flip the circuit breakers too OFF
A/C is turned OFF ?

try again

if the inverter is HOT to touch and nothing works , 'no power'
yeah its fried replace it

[time2roll]

I still assume "OL" stands for overload. Does it feed the main breaker panel? Was this factory install or dealer installed?

For testing you need to disconnect ALL loads to start. If you don't know how stuff is wired you could remove the output cable. Or at least turn ALL breakers in the panel off. Is the inverter there to power a residential fridge or just some outlets?

I suspect the inverter could be feeding the water heater and the converter. Did the inverter ever work?

Two golf batteries are a bit light for extended use of the microwave or other high draw item. You did say the lights dim a bit... this indicates a high draw on the inverter.

[2oldman]

Voltage alone does not indicate battery health. How old are they? Can you disconnect all loads and see what happens?