A/C keeps flipping the breaker!

Installed my A/C at the end of last month. Worked fine and then while cleaning the strainer basket, it took flight and landed at the bottom of the marina.

I bought another one on Sunday and installed it yesterday. This morning I got back to the boat and found only my blower running. No compressor.

I flipped the breakers off inside the boat and restarted the ac. Compressor was working, water was flowing.

Went back this afternoon and again found only the blower working. After flipping the dock switch and the breakers inside the boat again, compressor kicked on for a few minutes and tripped the breaker again.

Any ideas what could be causing this? My basket had a jellyfish in it and two or three minnows.

How was the outflow of water?
Was water flowing normally?

As normally as it was before.

Breakers can wear out and trip at reduced amperage. Try tightening the screw on the breaker, and other connections between the ac and the breaker. Then try a different breaker.

Make sure you're getting full voltage. You could be getting reduced voltage when everyone is running ac. Lower voltage means the ac draws more amps and could trip the breaker.

Start relay could have failed, or a start capacitor.
You can easily tell if you have an amp gauge on the AC power line.
It consumes too many amps which will flip off the breaker.

Based on the very limited amount of information that you provided I will hazard a guess. The high pressure switch in the AC has opened shutting down the compressor. The high pressure is due to insufficient cooling of the condenser coil due to hot sea water due to restricted flow possibly due to a new basket with smaller holes in the basket. I would examine the water flow after running for a few hours. Measure the water output with a thermometer at start up and then again every 30 minutes.

Cliff Meima said:

Based on the very limited amount of information that you provided I will hazard a guess. The high pressure switch in the AC has opened shutting down the compressor. The high pressure is due to insufficient cooling of the condenser coil due to hot sea water due to restricted flow possibly due to a new basket with smaller holes in the basket. I would examine the water flow after running for a few hours. Measure the water output with a thermometer at start up and then again every 30 minutes.

Click to expand...

If the high pressure switch tripped it would not have tripped the breaker it would just have shut down on high pressure. I think an ammeter is needed to see if there is actually an overload or whether it is a weak breaker. Checking all connections as pointed out earlier is certainly a must.

Greetings,
NOT an AC person but have been through a similar scenario. Things to check. As mentioned: restriction in raw water "loop", weak breaker or possibly dirty air filters, low Freon, compressor is on it's way out.

I agree with this:

Cliff Meima said:

Based on the very limited amount of information that you provided I will hazard a guess. The high pressure switch in the AC has opened shutting down the compressor. The high pressure is due to insufficient cooling of the condenser coil due to hot sea water due to restricted flow possibly due to a new basket with smaller holes in the basket. I would examine the water flow after running for a few hours. Measure the water output with a thermometer at start up and then again every 30 minutes.

Click to expand...

Non working water cooling wont flip the panel distribution breaker off, not in my experience.
As it gets too hot, the compressor high side pressure can go over 400 PSI, then the hi pressure cutoff switch turns off the compressor.

When it rests, hi side pressure falls, mine auto restarts.
Newer ones wont auto restart, they need to be manually reset.

Start with the simplest things first. Check the voltage with the AC running. Then check the current that the AC is drawing with a clamp on meter. If those are both good, change the breaker. If that doesn't fix it, then start worrying about the AC itself.

Ken

Cliff Meima said:

Based on the very limited amount of information that you provided I will hazard a guess. The high pressure switch in the AC has opened shutting down the compressor. The high pressure is due to insufficient cooling of the condenser coil due to hot sea water due to restricted flow possibly due to a new basket with smaller holes in the basket. I would examine the water flow after running for a few hours. Measure the water output with a thermometer at start up and then again every 30 minutes.

Click to expand...

Well, water has been low. We’re only floating in about 3’ right now and temps have been around 97 the last two weeks so the water is extremely hot. Even the pool at the marina is like a hot tub.

It could be that the water is too hot. If you want to test that you can hook a garden hose from the dock to the hose coming from the strainer to the water pump and see if it works then. We had a pump go bad when we lived in Arizona so we hooked up to the dock water so we could run the A/C temporarily. Not sure if it would hurt the pump or not since we hooked it after the pump that had gone bad.

Turn the system off for 10 minutes and allow the compressor to equalise. If it starts and runs but then trips when the compressor cycles out (rotor lock) you may well find your problem and need the services of a A/C repair man
I agree with the comments on amp draw, run current against voltage is the simplest way to understand whats going on - you may have a simple power issue - low volts / high amp situation.

My Cruisair 16k btu heat pump draws 10 to 12 amps depending on temp.
But instantaneous starting amp draw may be 50 to 60 amps.

If my start relay gets stuck on, the amp draw is perhaps 25 to 27 amps, compressor motor gets hot, and it will trip the 20 amp panel breaker after a minute or two.

I upgraded the start cap to a higher voltage model, it used to blow that to pieces if the start relay failed. Now it just gets warm. I just replaced my start relay, it rusted on the inside and could no longer disconnect the start capacitor.

Some compressors may have a built in auto reset thermal breaker inside the compressor for self protection.

Delta Tango said:

Turn the system off for 10 minutes and allow the compressor to equalise. If it starts and runs but then trips when the compressor cycles out (rotor lock) you may well find your problem and need the services of a A/C repair man
I agree with the comments on amp draw, run current against voltage is the simplest way to understand whats going on - you may have a simple power issue - low volts / high amp situation.

Click to expand...

I can get the compressor to start by flipping the breakers on and off. It'll start, and will run for 3 - 4 minutes but then shuts off, just as the air starts to cool. Flip the breaker on and off and it will restart and do the same thing.

I guess I'm going to have to call my HVAC friend and have him come look at it because it seems to be a bit over my head.

I would check the wiring from the panel to the AC unit. If it is undersized, could cause the breaker to pop.
If I read the original post correctly, this is a new unit install, but is it a replacement for a older unit? was the AC water pump replaced? new?

I didn’t check anything, I didn’t change anything, I didn’t do anything except to decide I wasn’t going to worry about it.

And now it’s working. Go figure.

Doesn't sound like the breaker is tripping

The OP stated that the breaker was tripping but the fan was still running. It sounds to me like the compressor is locking out on a safety and he is resetting the safety by cycling the power OFF then back ON. The fan would not run if the breaker was tripped.

In this case the previous posts concerning warm water or flow seem likely.

Toocoy, you mentioned that the system is now working ok. Has the ambient temperature gone down? High cooling water temp. low water flow or high ambient temperatures all increase the head pressure which can cause the compressor to lock out.

Duvie said:

The OP stated that the breaker was tripping but the fan was still running. It sounds to me like the compressor is locking out on a safety and he is resetting the safety by cycling the power OFF then back ON. The fan would not run if the breaker was tripped.

In this case the previous posts concerning warm water or flow seem likely.

Toocoy, you mentioned that the system is now working ok. Has the ambient temperature gone down? High cooling water temp. low water flow or high ambient temperatures all increase the head pressure which can cause the compressor to lock out.

Click to expand...

Outdoor temps have been slightly lower and were floating in higher water again. When it was tripping we were only in about 3’ at the dock. We’re back up to 6 or 7 now.

Extreme tides, temps causing the issue?

Was thinking goofy CB, among other things but your last post if it now working with the deeper water, cooler, suggests that maybe the heat exchanger needs to be cleaned and the cooling water flow rate checked.
Reduced water flow and/or a dirty heat exchanger will cause your shutdown.

I would still be highly suspicious of the CB and it,s attached wiring as I,ve seen nuisance tripping g like that before. CB do have wear parts.

Sounds like you have a plan, HVAC guy. But ask I'm some questions so you will better understand in future. Hope he figures out quick.

Good luck

The blower going, water flowing but no compressor, the shallow, hot water certainly point to so rather arduous conditions for the unit to handle, leading one to consider the compressor cutout switch as the issue.

While it would not resolve that issue, when I first looked at the OP's post, I though maybe a soft start unit would help with the CB tripping. These things are BIG sellers in the RV market where people are using smallish generators to run AC unis. I did some research recently and reported prices from $570 for Dometic's Smart Start all the way down to around $165 for Micro-Air's Easy Start system where they ship you the board-only (minus their fancy case with capacitor and board enclosed). I elected to go with two Micro-Air CB-only units, one for a 13.5 KBtu rooftop unit on my boat, and the other for my new Dometic 10 KBtu marine unit both powered by my 3.5 KW diesel genset.