AC Pump Wont't Shut Down

[JLR]

Here's a new one. My air conditioning pump will not shut down even when the breakers to all of the AC units are off. Of course, I can shut it down with its own breaker. Any ideas?

 

[Pascal]

Must be a stuck relay. Open the relay box and test them one by one to see which one is stuck or turn the AC breakers off one at a time to see which one turns off the pump

Or it could be the control sending a run signal to pump relay even though it doesn't send one to ththe compressor

 

[Reefgeorge]

Stuck trigger relay/triac +1

George

 

[JLR]

Thanks all. I have all the breakers to the AC units off. The pump is still running. Where would the relay or triac be located? Are they near each thermostat, on each compressor/condensor, or in some other location? Your help is much appreciated.

 

[bobk]

Different boat, but on mine they are near the water pump on the compressor shelf. It is a rectangular blue metal box.
Bobk

 

[bigbill]

try turning the pump breaker off then back on. i had this happen 2 years ago and i flipped the pump breaker and it has not done it since

 

[tonytrakovich]

There is a pump relay trigger box mounted on the port side aft genny room bulkhead. It is probably white about 12” x 10”. Inside will be the pump triacs. There will also be trigger boards in there. There will be one trigger board for each compressor. When the compressor kicks on it sends juice to trigger board. Trigger board then controls triac operation. If this is on your 75MY, there should be 7 triggers that control 2 AC pumps. As others have mentioned, problem is probably in the triac. They tend to fail closed which will keep pump running. To test, turn off all power to pumps and AC compressors. Then check continuity between the two fat wires. They should read open. If one reads closed, it is the bad one.

 

[JLR]

Thank you all. Will report back when fixed.

 

[dastahl]

I have one that sticks every so often. Its on my todo list but I hit the A/C breaker panel for the
VIP unit with my fist, lightly. You can hear it trip and all is well sometimes for months.

Skooch

 

[JLR]

I used to have a bat for that. A good whack fixes a lot of things.

 

[racclarkson@gmail.com]

Had an LG flatscreen TV that would go black at an ever increasing frequency. When I got tired of turning it off for a cool-down session, I whacked the back of it with my hand--BAM SHAZAM! It fired right back up. Got to be ritual for at least two years. So much so, I kept a large rubber mallet on the TV stand. It was a real hee-haw when the screen went blank with guests over. Finally the frequency and the force required exceeded the load rating on the back of the unit.

 

[JLR]

Fixed. Bad triac and bad relay as well. Thanks for the help.