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41 CMY A/C issue

Posted: August 16th, 2024, 2:06 pm
by DarkJester
Of the three issues I'm experiencing this one is the most perplexing. I have only been able to go out to the boat on the weekends, and last weekend when I got to the boat the A/C units were not running. No power. None of the Circuit breakers were tripped at the main panel, but after much searching I found that the main Shore 2 breaker was tripped. (it's in the transom locker where the shore power cords are connected.) I have LED"s on my shore cords and they are lit on both ends. After resetting the breaker the A/C units came back on but only ran for about a minute then the breaker tripped again. Since the main power is being removed I don't get an error message on the AC Panels. I could only see water coming from one of the Thru hulls in the time that they were running. The strainer and seacock are in a place that my old fat body cannot reach. It was so hot that day (105) that I ended up with a mild case of heat stroke trying to get down there to get at the strainer.
I'm making several assumptions here:
1) the strainer is clogged, or the pickup thru hull is clogged with the durn grass that grows in the lake.
2) This is causing the pump to pull more current than normal and when the compressors kick on it's over 30A, and that kicks the main breaker at the shore power input.
3) Since I was only able to see one exit thru hull, I'm assuming that the others have lost prime.
I got fuddled during the day (Heat) and didn't follow my normal troubleshooting procedure. I should have turned all the units off and then turned them on one at a time.
I cannot reach the strainer from the mid salon hatch. I have heard tales that the aft master cabin stairs come out, but I was not able to pull them up easily. They have to weigh a metric ton. I f I could get them up I think I could get to the seacock and the AC Strainer.

Does anyone know a trick to get at the AC Strainer?
Has anyone had this happen to them? I'm really surprised that the Main Breaker tripped. Really the only thing on Shore 2 is the HVAC.
I'm tempted to call the HVAC guy that the Marina recommended, but I don't want to miss something easy I could fix myself.

thanks

Re: 41 CMY A/C issue

Posted: August 16th, 2024, 6:26 pm
by bud37
Let's face it mild heat stroke in those conditions is not an easy fix, your health is not worth the hunt, IMO sometimes the best course is a quick retreat. Try the guy , maybe it will be a relationship that will pay off over time.....you can watch what he does for future reference.

Good luck and take it easy in the heat.

Re: 41 CMY A/C issue

Posted: August 17th, 2024, 9:53 am
by km1125
You should shut the breakers off to the two units that aren't getting water flow. They will draw too much current and pop the breaker. Eventually they'd probably shut down with a HPF (high pressure fault) but you're tripping the breaker before they get to that point. The ONE that has water flow might work acceptable until you can fix the total problem, which is getting great water flow to all three units.

The water pump itself won't draw much more current if blocked. The impellers are usually magnetically-coupled, so they'll just stop spinning if there's too much resistance. They also need to be cleaned periodically if you have a lot of marine growth in your area.

There is likely only one pump, so if IT hasn't lost prime than it should pump to all THREE units and two might be blocked with some debris or growth. You might have to flush them individually. However, you might have more than one pump, so you might have to investigate and see where the intake hose goes to see if it splits after the strainer into two separate pumps.

But you will need to get to that seacock and the strainer. You need to exercise the seacock periodically and need to be able to clean that strainer periodically too.

One easy way to re-establish prime in the system is to take the dock water hose and squirt water "backwards" INTO the HVAC water exits in the boat. You don't have to squirt much in there to establish prime.

Re: 41 CMY A/C issue

Posted: August 18th, 2024, 1:06 pm
by Steve2020
The stairs on the 41CMY due come out for easier access to AC strainer and pump. I have found easiest way stand in bedroom open both doors on the side of the stairs grab the top of opening and lift. You also want some one in Salon to assist once they are part way up. Yes the are heavy and are slightly wedged in. Removing the stairs also makes it a lot easier to close the seacock for the starboard engine when cleaning that strainer.

Re: 41 CMY A/C issue

Posted: August 18th, 2024, 1:28 pm
by Midnightsun
Yep, stairs come out and now you have great access. I get on my knees on the salon floor and lift them out, have always done this on my own but yes they are heavy and awkward to carry. That being said I can confirm there is only one pump the manifolds off to all 3 units. The water from the aft and forward cabin units cannot be seen as the rear is under the swim platform and the front one is at the water line.

All depends on where you boat, after a season my stainer has a few weeds in it, still empty it and rinse it every winter layup and I run mine all summer long. Some places could be needing a clean on a bi weekly basis if there is lots of crap in the water. I have a feeling your strainer is plugged up, good place to start.

Re: 41 CMY A/C issue

Posted: August 19th, 2024, 3:50 pm
by DarkJester
Thanks Guys. Off to troubleshoot!
Oh, just for perspective, the lake I'm on is full of eel grass, milfoil, and hydrilla. They sprayed for it but it's pretty prolific.
The eel grass is horrible.

Jester

Re: 41 CMY A/C issue

Posted: August 19th, 2024, 5:17 pm
by Midnightsun
DarkJester wrote:Source of the post Thanks Guys. Off to troubleshoot!
Oh, just for perspective, the lake I'm on is full of eel grass, milfoil, and hydrilla. They sprayed for it but it's pretty prolific.
The eel grass is horrible.

Jester


Really sounds like a problem for all strainers for any subsystem that may be run. Since you do not know where the strainers aer located I must assume they have never been cleaned. Time to pull the stairs and get that eel grass cleaned out. ;-) While the stairs are pulled do check the engine stainers located in that same area. The generator stainer is located in front of the starboard engine and is serviced from the main hatch in the salon, between the engines.

Re: 41 CMY A/C issue

Posted: August 19th, 2024, 6:02 pm
by Alanna Mo Cree
Midnightsun wrote:Source of the post All depends on where you boat, after a season my stainer has a few weeds in it, still empty it and rinse it every winter layup and I run mine all summer long.

Strainer cleaning is a weekly maintenance item where we boat. I was gone for a month this summer and could barely pull the strainer out because it was so plugged! Amazingly, the salon A/C was still working even with such little water flow.

Re: 41 CMY A/C issue

Posted: August 19th, 2024, 6:30 pm
by Midnightsun
Oh my, guess we get used to our own conditions. Did not realize it could get that bad. Learned something new today. :beergood: