WFCO 8955 branch circuit breaker

As stated above you only have 120VAC wired around the circuit breakers. The 12VDC Power will be wired around the ATC FUSES...

Apparently this circuit breaker is providing 120VAC to the Microwave unit AND the Converter/charger unit using two poles. Both of these units require 120VAC to operate..

If you have the word DC POWER written into the label a better word would be CONVERTER... The Converter takes 120VAC and converters it to 12VDC to run all of our 12V devices when connected to Shore Power. It also charges your battery bank during this time. Both the Converter DC Output and the Battery Output Terminals are connected to the same point of the on the 12VDC Power Distribution Center...

This is a simplified 30A Electrical Block Diagram for the RV system



In my WFCO 8900 Series Distribution Center I have five full slots for circuit breakers. The 30A MAIN circuit breaker is a physical full size. The physical full size Circuit Breaker housing will handle the heat generated better than a physical half size breaker will. This is why you want the main 30AMP breaker to be a physical full size...

The remaining four slots in my case all have physical half size (One Pole) breakers installed and this gives me a total of eight possible separate circuits I can control. You can also install a physical full size circuit breaker that has two poles breakers built-in and accomplish the same thing of controlling a total of different circuits..

The physical full and half size of the breaker physical has nothing to do with the rated switch.

You can find the exact circuit breakers being used at LOWES in their electrical section..

Circuit breakers are easy to install and need no tools except to connected the cable...

This is an simplified drawing how to install a circuit breaker. Place against rail and then push down onto raised busbar. It is best to connect the wiring first... Be sure the 120VAC has been removed from the busbar before installing the circuit breaker (Turn OFF Main 30A Breaker).


My attempt at explaining it haha...
Roy Ken

When we got ours the WFCO and the hot water heater shared the same breaker. There was a spare slot so I added a new breaker for the WFCO only. Then the following year I got rid of the sorry WFCO.

The size of the wire determines the breaker amp size.
#14 awg wire is protected by 15A breaker.
#12 awg wire is protected by 20A breaker.
#10 awg wire is protected by 30A breaker.
I'm guessing that the previous owner had the 20A breaker tripping when the microwave was run along with the converter trying to charge up a weak or low battery. Or the 20A breaker was just worn out. Have a qualified electrician install the properly sized breaker and move the microwave to a different circuit.

Dbl Post

".........noticed it's connected to the DC power & the microwave."

It is the AC circuit breaker that feeds the microwave and is also where your 'Converter' is getting AC input from.
AC CBs are AC voltage only

30A CB is a bit over kill......change it out to a 20A CB as should be
(You should ave ONE 30A MAIN CB and at least four 20A Branch CBs)

As for the converter hissing/ lights pulsating.
Well it is a WFCO.
And it is most likely failing (lights classic sign).......check that you don't have a bad battery first.