Inverter By-Pass

[jack14r]

Jon, you are correct,shore or generator would power the circuit and bypass the inverter.Now I need it to fail again so that I can verify that it is the contacts.

[Jon Wehrenberg]

Jack....I am assuming your coach has Heart Interface 2500?

If the inverter internal by-pass fails it is just easy to replace the board. Going by memory there are two boards and they slide in. Be thankful you have the external by-pass because on my vintage none of us can get shore or generator power to any inverter circuit without accessing the inverters and connecting the sets of wire together. Had your coach been like that you would have been in trouble.

[jack14r]

Jon,I do have the heart 2500 interface inverters,I was really surprised that when I fired up the generator both legs worked.Liberty must have changed this a while ago.I will try to get Troy to order new boards since it is in warranty.

[Jon Wehrenberg]

This will be between us, Jack. Don't tell anybody.

If you inverter is part of the Liberty warranty, go for the whole inverter.

When it is your nickel go for the board. BTW, I'll bet even if it was your cost Liberty would try to get you to buy the whole thing instead of the internal parts required. Poor folks like me repair inverters.

[Jeff Bayley]

Merle&Louise-

I'm catching up on this whole thread late and haven't read all the posts yet but related to your post here on this thread, you mention about not being able to run your basement A/C without the generator being on.

What I did was install a toggle switch between my shore power breaker for two of the three A/C's (roof airs in my case) to two spare breakers I had on the house battery portion of the power panel. I have a 270 amp hosue battery altnernator on my bus although a 150 amp (more standard I think), might do the trick. When I flip over to the house battery side, my A/C's are running on the inverters and batteries. When your on the highway at RPM, the house battery charger is "refuleing" what your taking out with your A/C's on. I've had fairly good luck with it although I've had to change out the inline 300 amp fuses for the inverters and put 400amps (which Royal told me they've gone to now anyway and cleared me for the modification).

I (like you) thought it was silly to have to run the generator while trucking down the road to get more A/C so that's how I solved it. There's a thread somewhere in the site where I described it but would more less be redundant to what I described here.

Staying on subject, I also put a back up / auxilarry gas generator in the small rear bay that is on the passenger side of the XL-45's (40's don't have this particular bay). I hot wired a large extension cord to the shore power side of the fuse box with it's own breaker to turn it off and on. I took a clothes hanger and fashioned it to connnect to the Main power input breaker do that I can't accidentley back feed either generator. My panels are standard house type fuse panels instead of a Bass Panel like some others use. I use this little pony gen when I want one A/C when boon docking or very little gen/shore power and also as a back up in case the main gen goes out. With only 2,400 watts, you have to limit what you can run and I don't think this set up would be a suitable substitute to what John proposes (which I also want to make that modification) because I'm still running power through the inverters (for the fridge, house lights, TV, etc) but I AM by-passing the factory electrical for gen/shore with this mod and running power directly to teh gen/shore side of things. The house side of the panel still relies on charges batteries and inverters. I suppose I could find a way to also connect that pony gen to the house side breakers to run the fridge, outlets, etc in case the inverters fail.

So far so good, however, their is an inline surge protector above my automatic trasfer switch that recentley failed (not while I was using the aux gen). Conincidence ? Or is it possible I've got power back feeding even though I turn that main breaker off. I'm getting my meter out and run some checks to be sure that the little gen isn't leaking power somehow even with the main breaker off. Possible ???

I think I want to do the "John Mod" for the inverters failure which completlehy isolates and prevents any change of back feeding.

[gmcbuffalo]

I reread this thread after working on my inverters this week. I have three 3000watt Freedom Combi's 458's. I disconnected the 12 volts source to the inverters while working on the one unit. Bam!!!! no 120 volts circuited even through I have incoming shore power, and only one inverter was down by throwing the circuit breaker for it. My main power panel has breakers that are powered by the inverters and many more that are straight shore power or generator circuits. I least until today I thought they were non inverter powered. I will investigate more tomorrow but something that I don't know about must be powered by the inverter. Question: If you have no battery power to an inverter should you not still be able to transfer 120volts across the inverter?
GregM

[Jon Wehrenberg]

I cannot address this question on all inverters, but I believe if you have no connection to your batteries from the inverter, applying shore or generator power to the inverters has the potential to damage the inverter.

As long as the inverter has incoming 120V AC power, it switches from an inverter to a charger and it looks for battery voltage to regulate its 12 or 24V DC output.

Be careful Greg.

As a word of caution to all.....If you are going to do any work on inverters you must follow the instructions regarding the sequence of disconnecting power supplies, and in the absence of 120 V AC power the battery voltage is the inverter power supply creating 120 V AC power output.

Before attempting to do any work that exposes you to bare wires disconnect all power sources and then double check for the presence of voltage. I had an inverter that had zero output on the 120 V AC side of it until it had a load applied. I could put a meter on it and the output would read no voltage, but as soon as a load was applied such as a lamp (or your body) there was 2000 watts of output voltage. Be very careful around inverters.