For almost ALL 30 amp RV's you cannot run the 120 Microwave and the Roof AC at the same time(regardless if a 13.5k or a 15k). The Microwave pulls about 11 amps. The Roof AC on hi fan/cool pulls about 12 to 15 amps depending on the model. So lets take 12 amps plus 11 amps 23 amps. Way below the 30 amp limit. BUT, what did you forget? Yes, the refer 2.6 to 3.0. The Power Converter 1.0 to 3 or 4 depending on the 12 volt load. So now we are at 23+3+2 and now have 28 amps. What about the other 120 appliances in the RV. TV Coffee maker, ANYTHING that is drawing 120 current. So, in a real world application, you can see that 30 amps will not cut it. JUST BECAUSE some have a lower amp draw AC or less appliances ON and can run on 30 amp does not mean most can. This is a common complaint I get in Texas Heat when customers have 30 amp RV's. Last, what if the OP has a 120/LP water heater. The 120 side pulls 10.5 to 11 amps when heating. The OP does not have a defective part problem. He is overloading his RV supply and the breaker is doing its job. Doug
