trouble running A/C on Genset

[brocansky]

Hi,
I recently bought a 1999 Sunsport (30 amp) from a private party. The manual I rec'd is very generic and high level. There is a switch located next to the converter (I think that's what it is - it has both the AC and DC fuses). What does this switch do? It looks something like this:
---------------------------------------------------------
REAR SHORE FRONT
G
E
N

B
O
T
H
AIR CONDITIONER
---------------------------------------------------------
I can only switch between "Rear" and "Front". It is a twist knob.

The reason I ask is because I cant seem to run both of the A/Cs off of my Genset (with nothing else running). The A/Cs have not been consistent. The front A/C seems to blow fine most of the time, but the rear A/C either works fine, doesnt turn on, or blows warm air. I am guessing it is an A/C problem, but I am curious as to what that switch does. I just bought this RV and havent even taken it out yet. So, I havent been plugged into 30amp service (only have 15 at home).

A follow up question: If I was running both A/Cs and then ran the microwave, wouldnt one of the A/Cs kick off until the Micro was done, then kick back on?

I know this was long, so thanks for reading.

Regards,
Stan

[by8s]

Stan:
Assuming your genset furnishes you with 30 amps, same as shore power, it appears you are overloading your system, You should only be able to run one A/C at a time. There are other things using electricity such as your converter/battery charger or inverter (whichever you have). your refrigerator, lights etc. You need to familiarize yourself with how much current everything uses. You shouldn't even be able to run your microwave with one A/C running. I know my A/C's use 15 amps each (I have a 50 amp unit), but with two A/C's running I could be pushing the limits if I also used the microwave. I am wondering if you are kicking circuit breakers off when you try to run two A/C's. A friend of mine has a different make motorhome and he has some kind of electrical panel that will only let one air run at a time.
When your rear air blows warm air, chances are there is not enough current available to run the compressor. There again, it seems a circuit breaker should pop.
Your owners manual should have a chart that tells you how much current everything uses.
Hope this helps.
Bob