Inverter/shore power problem

[JJvike]

Hello all,

I need some help if you guys can. Drove to in-laws in Virginia today. Father in-law, retired licensed electrician, had me bring the items to convert his old 3 prong to the 4 prong we use. Added the ground and connected the plug. Plugged in my extension cord and tested the voltage. All normal readings. 240V with a dedicated 40 amp fuse.

Connected RV and inverter started to show an internal fault indication (5 blinks every 4 seconds). Disconnected, shut down everything, and went back to generator. Fault cleared and all was normal again. Wanted to try the shore power again. Shut down everything. Connected to shore, inverter showed AC in, then almost immediately went to the same internal fault. Back on gen power as I type this.

First question, what causes an internal fault? Thought it might be AC overload but that is a different fault indicator.

Second, anyone know the inverter tolerances for AC input? Is it exactly 240V or it shuts down?

Third and last, what is the longest someone has run their generator. We are supposed to be here until Tuesday morning. Definitely need AC during the day for the pets and us.

Thanks

[JTN8]

Not sure about the electrical issues but I've run my generator for four days straight while dry camping in the infield of a nascar race. I always run the generator when traveling in the summer and run it for a few days straight whenever dry camping with no issues at all. They say they last longer and run better when they get used. Make sure you are full of diesel though! I usually figure on a half gallon of diesel an hour is the burn rate at half load. Sometimes depending on the load I may only burn about a third of a gallon an hour but it just depends.. Figure 4 days straight you're going to burn about 48 gallons of diesel. Hope this helps.

Jason

[Superchief]

As for the generator, it will run as long as you got diesel fuel (little less than a quarter of a tank - so you can start the motorhome. Generators love to run - just make sure you are not also plugged into shore power at the same time.
As for the wiring issue, 240 for a motorhome is not wired the same as 240 in a house. RV 240 is basically two legs of 120 in. See attached photos. Hope that helps.

[Evereddie]

You are saying inverter but I think you really mean convertor. An inverter changes 12 volts DC to 120 volts AC.

Now as far as the voltage goes, you mentioned 240 volts. That may be what you get if you measure between the hot legs but no part of your trailer should be running on 240 volts. The diagram in the post above mine is good and will help you see what is what. If you plug your trailer into shore power the receptacles should measure 120 volts. Do they? You may be supplying too much voltage if it was wired wrong. If you are wired wrong and 240 volts is getting to your outlets I hope you didn't turn on your TV or microwave, or electric part of your water heater, etc.

[JJvike]

Thanks for the quick replies. I did mean converter, just called it inverter because that's what I call the piece of equipment.

Superchief, My father in-law just checked the lines again the way the diagrams showed.
122V on one and 122V on the other. 244V total. That can fluctuate up here. Sometimes it can drop to 236V depending on demand. This area of Virginia provides the power to Pittsburgh. Go figure. He assures me that those are within tolerances and I'm deferring to him. I am a little confused about the second diagram picture. It shows the 2 hots producing 220V. Which should it be, 240V or 220V? Or am I missing something. If it is 220V, then it's generator for me and I'll be off to buy fuel.
All appliances are working, I'm just concerning that I may have done something to the Inverter/Converter. I guess I'll call tech support today.

Thanks again,

[Superchief]

No, you are correct, it should be 240 (Internet can't add). The only other thing I noticed in your original post was the mention of a 40 AMP breaker. If you are using a 50 AMP feed system, I would think you would need a 50 AMP breaker.

[JJvike]

Yeah, that's what I thought when I saw it. I'll ask the the folks when they open up.

[Evereddie]

Sounds like your wiring is probably good but have you checked each of the hots to neutral? Each one should be 120 volts. (give or take) That neutral must be working and strong for this all to work. That's why I asked if a receptacle shows 120. In fact it would be a good test to look at this 120 after you power up the RV on shore power and the converter is running.

[boowho]

Originally Posted by Evereddie

Sounds like your wiring is probably good but have you checked each of the hots to neutral? Each one should be 120 volts. (give or take) That neutral must be working and strong for this all to work. That's why I asked if a receptacle shows 120. In fact it would be a good test to look at this 120 after you power up the RV on shore power and the converter is running.

If the neutral is "open" it will cook everything in the coach; you'll be getting a single 220-240 circuit instead of two 110-120 circuits.

GOOD surge protectors check for this condition and shut everything down if the neutral is open (or becomes open). Also, the 50 amp rating is for a single leg, so with two legs you actually have 100 amps available..... At least so I've been told; and it makes sense to me.

Boowho??