Cruiseair A/C Issue

[John F.]

Crows Nest has a Cruisesair A/C that Doug bought used about 15 years ago. It's always worked fine. It has a digital control that has worked for setting the temp. and whether the unit is on a/c or heat, but has never worked for on/off. Doug just threw the breaker to turn it off. As I remember, you could turn it on from the digital control. I keep all my breakers in the "off" position unless I'm going to use whatever (fridge, outlets, a/c, battery charger).

I haven't used the A/C since last year, and that was just to check to make sure it worked. I tried to turn the A/C on the other day, and as soon as I turned the breaker to "on," I could hear the A/C unit start, the pump start, and then within a couple of seconds, the breaker would trip to "off." If I tried again (and again), it'd just trip faster.

So, any ideas? Could it be the control unit is all the way done? If it is, should I get a digital or non-digital control? Any other ideas?

Shore power/electric stuff scares me a little. If its anything other than something simple, like the digital control is bad, I may just take the unit out and bring it to the local cruisair place (if they're still in business) and have then check it out.

Thanks.

[Navatech]

I'm not sure you have an electrical problem... These symptoms sound more like a high pressure cut out to me... Make sure your seacock is open and that the strainer is clear... Then have somebody turn on the system while you're keeping an eye on the A/C cooling water discharge thru hull... You should see water coming out almost immediately... If it doesn't it's time to look at the cooling pump... If it's a rebuildable type a rebuild probably will do the job... Otherwise, it's time to grab your credit card...

[Bruce]

John,
A high pressure cutout, lack of water causing head pressure to increase, then restart would take more than a couple of seconds to trip breaker. The reason the breaker trips faster is your trying to start the compressor against higher head pressure. Like trying to start locked up engine. Not good on the compressor.
I would measure current on startup and compare to breaker rating.
You could also have a weak start/run capacitor causing a higher than normal current draw.

[Hueso]

John:

What everyone said. I have a check valve in the raw water hose between the strainer and the pump to avoid this. However, when I do not use the a/c for a long time it seems like raw water dries out and/or back pressure on the pump is created. What has worked for me (and I do not know if this hurts any part of the system) is to hand press/pump the raw water hose right at the entrance of the pump when I turn it on and, as Nav said, have someone check the A/C discharge thru hull, which should have water coming out immediately.

[Navatech]

I have a check valve in the raw water hose between the strainer and the pump to avoid this. However, when I do not use the a/c for a long time it seems like raw water dries out and/or back pressure on the pump is created.

Yes, in some (bad) installations the pump can lose priming... The proper way to install such systems is as follows: thruhull, seacock, strainer, pump... It's important to locate the pump below the water line and to have the strainer top just under the water line... This way just opening the seacock will prime the pump... Some strainers will have a priming valve on top... On my Berty I don't have one... But I open the seacock just before I completely reinstall the top cover... I'll get maybe a gallon or two of water into the bilge before I finish tightening the top cover...

[John F.]

Thanks for all the suggestions. When I started to check stuff out, it turned out to be a loose wire (or two) to what looks like a solenoid. It works. Woohoo!!

[Navatech]

Thanks for all the suggestions. When I started to check stuff out, it turned out to be a loose wire (or two) to what looks like a solenoid. It works. Woohoo!!

I'm guessing but that sounds like either the HP sensor or the starting capacitor... Anyway, it works so all is well!...