Power Panel cross over switch

[gjrylands]

Just off the top of me head, I thought I could install a relay inside the power panel. The coil side of the relay would be connected to the output of the breaker that powers the mian the ac unit that controls the pump. The switch side of the relay would be connected between the breaker powering the second air conditioner and the input lead going to the unit. That way the primary air conditioner would have to be powered before the second unit could receive power. Everything else remains the same and I don't have to mess with the ac control box.

[prowlersfish]

Gerry I am not sure what your trying to do . I don't under stand why you what have one a/c powered up befor you can turn the other on ? Am I missing some thing here ? ( wont be the first time LOL) Are you having trouble with the pump coming on with one of the A/C units ?

[gjrylands]

No. Both units work fine and the pump runs when either unit is turned on. I would only put the relay in if I run the units off different sides of the panel, hence off 2 power cords. That way the primary unit would have to be ready to run before the second unit could be turned on. This would keep the second unit from running without the cooling water provided by the pump powered by the primary unit.

The primary unit would not have to be running, It only has to have power running to it. That way when the second unit is turned on the pump could run. (The primary unit must have power so the pump will run.)

[prowlersfish]

Gerry I got you . But I think I have good news I think you will find the A/C systems set up on diffrent cords relay for the pump is there . The relay box should be near the a/c units . mine was/ is under the floor below the lower helm .

One thing you will find is you turn off one power cord and turn the a/c on the pump way not turn on unles you hit the " jumper switch " this is petty normal way of doing it as every boat I have seen with duel A/C has been set up this way . a liltle strange compared to house wiring but it works .

a side note ;you know a black wire is hot in a house . And in car its ground in the 12 volt system . well on a trojan (andsome other boats )
Its the hot wire for the shore power Like it should be . and on the 12 volt side its the hot (possative ) side ..... Some times ! you just got to love it ,
it can drive you nuts tracing something on the 12 volt side And if you have a brain fart it can lite you up on the shore power side . How do I know ? wella month ago I was replacing the A/C pump and did not kill the corect braker and ...... dam that hurt! I should know better !

[gjrylands]

That right, the ac control box is below the helm. Both ac units are there as well.

I know both ac & dc wiring in boats. I've owned a Trojan since 1972. I'm on my third and have done extensive work on each of them.

[raymond workman]

It sounds like a good survey or reading the labels could have save you some money. Thx for shareing learn something new everyday on this sight. I dont recall seeing any stickers at all.

[prowlersfish]

Raymond you would not have the sticker as your boat would have a single shore power cord .


One thing we all should do is to check all the conections in the power pannel. check for being tight and not being burt or coroded . A bad conection can get real hot poss causing a fire . unlike a short a bad conection will not trip a breaker . UNPLUG THE BOAT before doing this !

Check you shore power cords look for burned termals on each end.
if you find a burnt end you need to replace the cord, But you also need to replace the sockit on the boat if that end is burnt or if its burnt on the dock end have the marina repair there end .

Gerry , care to add anything ?

[gjrylands]

Corrosion can form in the female socket of the shore power cord and dock receptacle. It’s this corrosion that causes the terminals to over heat and burn. Radio Shack sells an aerosol contact cleaner (TV-Tuner Cleaner/Control Cleaner/Lubricant #64-4315) that can be sprayed on the connections. Spray the connections and plug the cord in a number of times. This will clean and lubricate the contacts. This will keep them in pristine condition. TURN THE POWER OFF BEFORE SPRAYING IT IN THE RECEPTACLE. The spray is non-flammable, but let’s not be stupid. Salt water environments are very corrosive so it is extra important to use the spray regularly. For those of us in fresh water, a spray every couple of months will do it.

Another thing to look out for is a loose fitting receptacle. When the plug is inserted you should feel a resistance as the prongs slide in. A loose fit can be a poor connection that again can burn your cord. Preventative maintenance is best.