Air conditioner tripping breaker

[williamnugent]

This is my first season on a '96 355 AC and have had issues with the AC. Most recently, the air conditioning unit in the aft birth keeps tripping the breaker on the panel when in the hearing mode. I've tried to find filters to clean, but can't find any. Accessing the back of the unit (where I believe the grill is) is impossible (facing the port hull). Am I missing something?
Thanks...
Bill Nugenr

[mjk1040]

Bill, I think u mean heating mode, if you have the manual on this unit which I be is a 12,000 btu unit, you will find there is or was a thin foam filter stuck to the front of the condenser. The one to our forward unit was deteriorating, so I threw it away. since as you said its very hard to get at. Now I can put the vacuum hose in the front of the unit and use a blow gun to clean out the condenser coil. Back to ur issue of tripping the breaker, in the manual I believe if I understood it correctly has 2 heating modes. One is just using the heat from the water going thru the condenser cooler and the other is a electric heating element. You can program the unit either way. It's possible the heating element is getting bad and drawing to much electric in the heating mode. Don't know if this element can be replaced or not? Try, if u can, reprograming the heat mode to heat with the water only and not the element. If the AC parts works fine and its just the heat part giving u trouble, I'd run it till it died and then replace the whole unit. If you need more heat than just the water will supply, may I suggest a 1500 watt ceramic heater to supplement your heat needs till you have to replace the entire unit. Mike

[Lyndon670]

+1

Another item often overlooked is the actual breaker itself. Overtime these can become "weak". I had the identical problem on my Silverton and after much diagnosis, I replaced the breaker with an identical NEW breaker of the same size. Problem instantly solved.

[Viper]

Bill, does this happen only in heat mode and only with this particular unit? Does it happen even if it's just that unit working and the others are off? If so, it could be as weak breaker as Lyndon noted. Also check to ensure the plugs at both ends of the shore power cord don't show any signs of overheating at the contacts. Check the boat's inlet plug also. Other possibilities are a board issue, a bad reverse valve, or a short in one of the wires on the unit or controller box.

[williamnugent]

Thanks everyone for these excellent suggestions. I checked and found that the AC unit in question was already set to reverse flow only, though I went ahead and reset the unit to factory defaults anyway...
Still through the breaker in heating mode.
So far, the only electrical issue plaguing me is with this unit, though I'll check the lines coming into the boat. (I suppose I could try running it off the generator and see what happens).
I had it running on cooling mode for a while last night and it seemed to work.
Arrgh...

[Viper]

Qr Bbpost....I checked and found that the AC unit in question was already set to reverse flow only, though I went ahead and reset the unit to factory defaults anyway....

The reversing valve failure would be the valve assembly itself, not a setting. This is an electrically operated valve in the refrigerant circuit/system that redirects the refrigerant depending on whether you want the unit to heat the room or cool it down. If the valve is stuck in the cooling position, the solenoid could be tripping the breaker in an attempt to move the stuck valve, or it could have a dead short that trips the breaker upon activation. The other possibilities mentioned above that would control that circuit also apply.

When you have it working on "cool", how long does it take to trip the breaker after you switch it to "heat"?

[williamnugent]

When I switch to heat mode, either directly from off or from cooling mode, it will heat for about 5 minutes then trip the breaker.
When it is heating, it does produce warm air.

[Viper]

Just to be clear, you can run on cool mode all day without tripping the breaker? What is the make and model?

[Viper]

To eliminate the breaker as a possible cause, if you're comfortable working with electricity, unplug the shore power cord, open the electrical panel, and swap the wire on that breaker with one from another AC unit breaker and try to duplicate the fault. If the same unit works fine after that, replace the breaker. Keep in mind you'll have to switch on a different breaker this time to test it. If you swapped the wire with the mid AC breaker, that's the breaker you'll have to turn on to test. After testing, return the wires to their original breakers.

[Lyndon670]

Beat me to the punch Viper!