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Randall, RVIA Certification
Category: RV
Satisfied Customers: 11280
Experience:  RVDA/RVIA Master Certified Technician with many years experience.
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Heart Interface inverter problems.

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I have a Heart Interface Freedom Model 20D Inverter. The on/off switch on the Inverter is off. I have a remote control mounted in the closet of the bedroom. The Inverter runs with the remote switch in the off position. (I hear the fan running) I assume it is attempting to charge the batteries. I have four 12 volt batteries connected and all test 12.5 volts. The fuse in the cable tested good. When the remote is turned on, the battery and overload lights are flashing. With 50-amp shore power connected, both A/C work and some outlets work. NO GFCI outlets are tripped. The Microwave and 120 volt lights are on the same breaker as the Inverter, they do not work. If I disconnect the battery cable to the Inverter with unit and remote in the off position, you can still hear the unit running (fan motor). If I trip the breaker for the Inverter the unit stops. None of the breakers on the front of the Inverter are tripped. Any ideas?

The battery and overload flashing (and I assume the charge light is blinking green and the inverter light is off) indicates a back feed shutdown. You have either got a short or something wired incorrectly on the AC of the coach.

If you have recently had any electrical work done at all, you need to start there to find the problem.

The issue could be a neutral/ground cross, but will most likely be a hot/neutral cross.

Customer: replied 6 years ago.

The InvChg light is steady red. I have not had any Elec work done. On the display I have the following under status:

Battery: This is blinking red.

Overload: This is blinking red.

AC Input: This is not on.

Inv/Chrg: This is steady red.

Are the battery and Over Load lights blinking slow or fast?

Customer: replied 6 years ago.

They are blinking fast.

This is a situation I have never seen before.

Let's go ahead and totally reset the system, to resynchronize the remote to the controller.

Unplug the RV shore cord.

Disconnect the grey remote wire (phone cable) from the unit.

Wait 15 minutes.

Reconnect the shore cord, then reconnect the remote cable.

See if this will take care of it.

Customer: replied 6 years ago.

Okay, I'll give a try. I will let you know.

No problem. I really hope this is all it is.

Customer: replied 6 years ago.
I cut the shore power, disconnected the remote wire, and reattached the battery cable. I can hear the unit running. Should I remove the battery cable?

Yes. Disconnect all power sources from it.

Let's de-energize the entire thing.

Customer: replied 6 years ago.
Still got the same problem. The AC breaker box inside the coach has one breaker that is for the Inverter, all 120VAC Lights, Electronics, Icemaker, Microwave, and some outlets. None of these items will work. Everything else in the coach works. With shore power connected, battery disconnected from Inverter and this breaker tripped the Inverter is off.
If I trip the breaker back on, with the phone cord unplugged, the unit power switch off, I can hear the Inverter fan motor running. I now have shore power connected, the breaker for the Inverter off, the batteries disconnected, and the phone cord to the remote unplugged, the unit is not running. If I connect the battery cables the unit automatically runs or if I trip this breaker it runs, this is with the unit switch on off and the remote wire unplugged. I assume it is in charge mode. All batteries test 12.5 volts.

Go HERE for a copy of the manual for this in case you don't have one. See page 33 for the status lights and what they indicate. Those you mentioned indicate that the batteries are trying to equalize and that there has been an overload condition and they are trying to cool. The most common problem on these is with the batteries. Have them tested for shorted cells and reserve capacity with something like a Midtronics tester which can detect these things. Just taking a voltage reading doesn't tell you much. They might have good voltage but for just about 2 minutes. Be sure all the cables and connections are free from corrosion.

Get back to me if you need more help on this after you have them tested.

Customer: replied 6 years ago.

Thanks, I downloaded this manual last week. When I first had the problem, I had the batteries load tested and three of the four were bad and were replaced. I assumed this would clear up the problem but it didn't.
I am now thinking one of the cables from the batteries on the right side of the coach running to the Inverter on the left side of the coach is shorting out against the frame due to wear.

You should always replace the batteries together otherwise you take the chance that the one left will go bad and that can ruin the others sometimes. Shorted cells are hard on the batteries that are good. Are you sure that the cables between the batteries and the inverter are large enough? These runs need to be very short or larger cables need to be used. Most of the time the inverter is mounted right next to the batteries. Also, be sure you have them all wired up correctly. All it takes is one wrong and it will cause all kinds of problems. Checking all the cables should be done and replace any that have heavy corrosion between the terminal end and the wiring. High resistance results and on this system, isn't good.

Customer: replied 6 years ago.

The cables are wired correctly. I cleaned all cables and replaced two of them. There are large cables running to the Inverter they were not replaced.

So, you have two batteries on the far side of the coach away from the inverter? What size cables are those? How far is the run between them to the other batteries or do I have this correct?

Customer: replied 6 years ago.
I have four batteries tied together with large cables and large cables going to the Inverter. The cables are 2AWG.

Am I understanding that some of the batteries are not near the inverter and on the other side of the coach or all they all together?

Customer: replied 6 years ago.
All four batteries are on the far side of the coach. None are near the Inverter.
How far away is the inverter from the batteries? And the feed cables are only 2/0?
Customer: replied 6 years ago.
Correction they are 3/0 and they are 6-8 ft from the Inverter. All the main cables are original with the coach. I only replace two that connect the batteries together.

That may be part of the problem. Most cables between the batteries and the inverter are 1/0 and located near the batteries. This is only a 2000-watt inverter but you still are going to tend to overheat this when you get towards maximum load. I don't know if you have measured the loads you have on it doesn't take much to exceed 2000 watts, especially if you are using a microwave. Those codes on the troubleshooting indicate a unit that is overheating and that happens when you use too much power and have undersized cables. This wouldn't be the first time I have seen something wired up with too small a wire from the factory. It happens more often that you would think. You must have larger wire to "move" that many amps over when the load is high. If you don't and the voltage goes down then the amperage goes up and so does the heat in the circuits.

I would use at least 2/0 cables and consider even 1/0 if you think you might increase the size of the inverter later on. Most Class A coaches now have about 4000 watt inverters for this vary reason. Most people just can't resist using more power. In your house, most people don't ever have to worry about it. Here is can be critical.

Hope that helps.

Customer: replied 6 years ago.

I never use the Inverter to power up anything. I always use shore power. However, with the Inverter on the same breaker with lights, microwave and some outlets it will not let these items work on shore power. This just happened and I need to be on the road.

I always use shore power and rarely use the inverter. However, there is an AC breaker for the inverter, that also has all the 120VAC lights – microwave and TV, so none of these work on shore power, because of the problem with the inverter.

That is the way most are wired up. They had quite a few problems with the remote on these. It might be just a fluke and it might be a problem in the inverter itself. I gave you the things you can test for. After that you have to have it professionally tested out of the coach. That is about all I can offer you on this.

Randall, RVIA Certification
Category: RV
Satisfied Customers: 11280
Experience: RVDA/RVIA Master Certified Technician with many years experience.
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Customer: replied 6 years ago.

Thanks, for your help.

You are welcome and you can come back to this if you need to later.