Liberty Inverter AC Input Problem

[VegasDogMan]

Problem I'm having is AC Indicator on Inverter Remote Panel is going On and Off. I have two inverters - one is running normally and the other is showing this problem.

Thought it was a problem with the Park Power so disconnected from pole and ran off generator and see same problem.

Last night I also saw my 120V lights flickering (inverter output).

I can hear what sounds like a thermal relay going on and off somewhere in my galley area when my AC light on Inverter changes from on to off or vice versa.

My guess is the problem is either in the charger section of the inverter or between the AC Breaker for the Inverter/Charger and the input to the inverter. Haven't gone out yet to put meter on either inverter AC input as yet. Don't know which inverter is one giving error indication as yet.

Anybody know how the AC Input to the Heart Inverters is wired on a 97 Liberty?

[Jon Wehrenberg]

Lee,

The breaker(s) in the Liberty panel on my 97 have two sets of #10 ga, three wire stranded cables going to inverter. (That is 2 sets of wires, input per inverter,) The inverter has one input set going to the battery charger input wires, and one set going to the inverter transfer switch. The transfer switch is internal to the inverter, and when that circuit has 120V AC input, such as shore power or generator that internal transfer switch sends power to the AC circuits in your 120VAC circuits supplied by that inverter. I believe the breakers in the panel are 50 amp.

When your inverter senses input power, the inverter battery charger section functions, and the 120VAC to the transfer switch merely passes throught the inverter to your 120VAC panel.

When the inverter fails to sense 120VAC input power, the inverter uses battery voltage to convert from 12V DC to 120V AC to power the 120VAC panel circuit breakers.

I guess you need to determine first if the inverter 120 Volt circuit breaker wires are securely attached. Then verify there is no fluctuation in 120VAC power in to the inverter. If those are uninterrupted and are not fluctuating then it seems as though the inverter transfer switch may be acting up or failed.

The boards internal to the inverter are easily removed if you determine the problem lies with the inverter. All of this assumes you have Heart Freedom Interface 2500 Watt inverters.

[jack14r]

As Jon pointed out the boards can be easily replaced,but also the contacts that allow the inverter to be bypassed sometimes need to be cleaned.They are in the front of the inverter,I used 320,400,600 sand paper on mine,I cut the sandpaper into 3/8 inch strips in order to get around wires etc.Before taking the cover off be sure to disconnect shore and or generator and turn off the incoming 24 volt disconnect to the inverter.Mine would not invert but would bypass on shore or generator.

[VegasDogMan]

Changed current setting from 30A to 5A and that eliminated problem. Possibly I have a current sensitive relay or connection betewwn power anel and Inverter Input on 120AC input that fails when larger load on charger.

Had power failure in park last night and bateris were pulling charge this morning when I noticed problem.

Will try to check it out with meter tomorrow if I can get it to fail again.

Thanks....

[Jon Wehrenberg]

Lee,

I was about to type something else for you to consider when I saw the posts from Jack and you.

I had an incident a long time ago in which one leg of the campground 50 Amp power supply failed, but it did not trip the breaker. I noticed the problem by the absence of an AC input power light on the remote inverter panel.

I should have mentioned that earlier but forgot. Check that you have good power into the coach before you tear into the coach itself. Your reduction of charging current may be a clue that there is some resistance through that circuit from the power outlet all the way through any other current carrying contacts to the 120 VAC CB panel in the coach. I would not rule out the coach transfer relay.

I want to echo Jack's excellent advice to disconnect all power sources to the inverter if you choose to get in there and work on it.