Trojan Boat Forum

I have no documents telling me how to operate the A/C. Currently, I turn it to START, then in about a minute to run. Turn fan to low. However, when I turn the last control to cool, it blows the main breakers. Am I starting it up incorrectly or is my compressor shot? Can a small household room A/C be installed thru the wall or window behind the bridge ladder? Sure would be cheaper than a service call from the marina. '78 F28.

Looking for suggestions and options.

Thanks

Might be an airlock in your water line. Trying blowing out the waterline with air and then try it again.

Worth a try for sure. The compressor kicks in for about 2 seconds and the mains blow. I'll only using it in the slip in this 100 degree TX heat. My boat house is covered on three sides and we get no prevailing winds......ugh. I do see, however, Frigidaire makes a small 5000 BTU mini unit that's only about 16x13x12 +/- and has great reviews. Thinking about making a cart and running it off my 1000is generator. Only pulls 515 watts. Make a shroud and use a flex hose and dump it down the front hatch w/ AC and genset on dock. And since it will be portable, I can use it at home in the workshop etc. Techs want a ton of $$ just to show up.

Before you go spending money, do a few simple checks; ensure that your shore power cord and dockside pedestal plugs are in good shape. If you see any burn marks or signs of melting/heat around the contact areas, you have a poor connection which will cause excessive current draw. Also ensure that you are actually getting sufficient voltage; 120V or close. Do a visual inspection of all contacts both on the AC unit and the control panel; they must be clean and tight, don't forget to check right at the compressor; start relay, cut-up and capacitor. Also ensure that the water pump is actually working and has not seized, if it doesn't pump water before it trips the breaker, it's siezed. It could also be a weak breaker; switch the wires going to the AC breaker and connect to another breaker of the same amperage and see if that one trips also. If it doesn't, you likely have a weak breaker. Don't forget to unplug the boat first, bring the cord in with you, and ensure the generator is not set on automatic.

All good suggestions. If all tests ok, you can pick up a hard start capacitor for $15 (Supco #SPP5) and wire it in...very easy to do. Old compressors draw a lot more current than when they were new and this will handle the surge on startup. Eventually the compressor will burn out at some point, but this will buy you some time..months, years, who knows. All depends on how much you use it. Mike

If the Water pump is wired to kick on at the same time as the compressor and you want to eliminate the water pump as the source of the over current situation disconnect the water pump electrical connections and try to run the AC. it should run for a few minutes without cooling water which should be long enough to determine if it is the compressor or the water pump that is causing the breaker to trip.

Don't run it too long so the compressor doesn't over heat but this should point you in the right direction.

I'm guessing that the unit is old enough that there is no coolant flow interlock that would prevent the compressor from kicking on.

I have forgotten to burp/bleed my water pump a few times in the spring and the compressor comes on and begins to cool and will run for a few minutes before shutting down.

Just a thought...

Barry