air cond and fridge off with low bttery

[omnicare]

I have an interesting problem. My RV is a used 2003 National RV Palisades 5th wheel with 50amp. While taking a nap I noticed one air was off and the other "bogged down". I turned them off and started checking breakers etc. The TV, and outlets had power. I Noticed dim lights and tested batteries which were at 6 volts only. I checked all of the fuses (good) in the converter compartment. Did not hear the converter running. Checked power cord. Found one darkened wire (red one). It did not look like it had gotten hot but I changed to new cable and plugged it back in. Still nothing. Checked the battery again and noticed its voltage climbing. It got to about 8 or 9 volts and the air came on. Then a few minutes later the refrige came on. Later this evening lights got dim again and both air cond eventually stopped. I turn all lights off and after about 45 minutes or so the air started. Another 15 minutes later and the refrige came on when I hit it ( yea I hit it in anger). Now I'm in the dark. air is on (Thank God) and I put the refrige on Gas. All the while the outlets had ac power as my chargers and tv worked. Just the air and frige would not come on. So, there is a solenoid looking thing in the converter compartment. It seems the battery has to be charged up for the air and frige to work? Is this normal? The converter is a MagneTek 900 series and the little brochure I have says if the unit fails it will only charge 6 volts. I can accept a failure of the converter but why is there a solenoid controlling any a/c current if that is what it is? Marine power systems do not have anything like this. They have a/c and d/c chargers maybe inverters but the a/c is not dependent on battery charge levels.

[paz]

The circuit board for the fridge needs 12V to operate. If voltage drops too low, the board won't function. If the board shuts down, the fridge shouldn't operate on gas or electric.

Similar situation for the air. The thermostat runs on 12V.

If the converter is operating properly, it should be charging the batteries if they are low. Even if the batteries are bad and won't accept a charge, the converter should still power the circuit board for the fridge, the thermostat, the 12V lights, the water pump, etc.

[SUMDALUS]

Omnicare,

I concur with Paz.

All of the following appliances are controlled by a 12 VDC circuit board: Refrigerator, DSI Water Heater, Furnace, AND the Air Conditioner(s). {The flow of 120 VAC to the A/C's fan and compressor is controlled by a relay on the 12 VDC board -- and so is the 120 VAC to the Refrigerator's electric heating element! ___ In addition, most appliances need at least 10.5 VDC to operate properly.}

Normally, when plugged into shorepower, the converter (or inverter charger) provides all of the 12 volt power your equipments need. However, as your converter manufacturer states in their manual: "If the converter/charger does fail, the output voltage will either be cut in half (i.e. 6 VDC) or go to zero. This will cause your lights to be dim or not work at all. Please note that your battery will supply all DC voltage until it completely discharges." Sounds like you need a new converter. And don't forget to check your battery(s) -- since the lights went out, they may or may not recover from such a deep discharge.

The solenoid you described is probably a part of the battery disconnect system. Is your disconnect system operated by a small electric switch or by a manual switch. Willing to bet it's electric. RVs usually don't use solenoids to control 120 VAC.

Hope this helps.