Inverter/charger Issue

[smokeater75]

I had my motorhome at a dealer in California when we were down south this winter. I had a new Xantrex 3012 pure sine wave inverter/charger installed along with 4 Life Line deep cycle batteries. It wasn't a straight in and out because our original unit was from 2003 and the new one wouldn't match up.

The dealer contacted Xantrex and ordered a Xanbus system control panel. This avoided running 30 ft. of cable from the new inverter/charger to the energy management system up front.

That was fine with me until I went to run my generator with the motorhome running and my alternator over charge light came up on the dash showing 16 volts going to the battery.

The next issue happened when I tried to exercise the generator and realized I was only getting 1 leg of power to the energy management system and couldn't put a load on the gen. without the EMS shedding the load and shutting down appliances.

Now I am back in Canada 2000 miles from the dealer.

Any ideas. 

[wolfe10]

Sounds like two separate issues.

In terms of the generator, start by turning off both "on generator" breakers and turning them back on. Let us know if that restores both hot legs from the generator.

 

When the generator "overcharge light came on"/16 VDC, were both the generator AND engine running at the same time.  If so, difficult to tell which charging source (alternator or inverter/charger) was the culprit.

[smokeater75]

The alternator over charge light on the dash comes on when the engine is running with the generator on or if I'm plugged into shore power and the engine is running.

I turned the gen breaker off and on started the gen and my ems panel once again showed fifty amps coming in. 

[wolfe10]

47 minutes ago, smokeater75 said:

1. The alternator over charge light on the dash comes on when the engine is running with the generator on or if I'm plugged into shore power and the engine is running.

2. I turned the gen breaker off and on started the gen and my ems panel once again showed fifty amps coming in. 

1. Not sure this is a problem-- the charging source with the higher charger voltage will be primary. This happens on our sailboat when plugged in-- even to the extent that the alternator powered tach will not work with the onboard 120 VAC charger working.

2. Not sure I understand the issue-- assume you mean your EMS senses 50 amp service available.

[smokeater75]

The reset of the gen breaker has taken care of the ems only reading one leg. The second problem is the alternator over charge light on the dash panel going off and the volt meter showing 16 plus volts going to the batteries. Its seems like the engine alternator and the inverter charger are pushing the voltage above what the sensor is set for. I am going to try shutting off the charge mode on my inverter charger and see if while the engine is running it still shows over charge. If that doesn't work I also have a dedicated starter battery charger that I will disconnect and see if that is the problem.

[wolfe10]

Good.  So likely one of the two on-generator breakers was tripped.  So that part of the problem is fixed.

Yes, you are on the right track for determining which charging "system" is overcharging the batteries.  If you have a diode-based battery isolator with external sense wire, first place to check is that both ends of that small gauge sense wire are clean and tight an that the alternator end reads the same as the chassis battery.  What happens if there is any resistance between chassis battery and alternator on the sense wire is that the alternator receives a false low voltage reading and boosts it. 

Another way to verify that the inverter/charger is not the issue is to just turn off the 120 VAC breaker going out to it (in main 120 VAC breaker box).

[smokeater75]

Thanks Brett, I will let you know how I make out. 

[rossboyer]

If the alternator does not see battery voltage, it will go to maximum charge rate at 16 volts. Might look for a broken wire or one not connected. Had the same thing happen on my Chev Equinox when the positive post on the fuse box overheated and caused the sense wire to be disconnected.