38' boat a/c air conditioning problem

[toptech]

Picture a little water cooled condensor sitting in the hull of your boat.
Small fractional copeland compressor, condensor cooled by sea water.
System was oringinally a heat pump.
Compressor failure, slide valve failure, and numerous leaks we decided to go staight cooling.
Installed new compressor, piped liquid out of condensor into small 3/8" brass flare tee which feeds to evaporators
on the boat.
The evaps are cap tube type, r-22 with variable speed blowers.
Evac system @ 500 microns and initially charged with 1.5 r-22
Start system, suction @ 40 liquid @ 150, sea water @60-65F
Added refrigerant suction @68
Head @165 or so, super heat @ evap # 1 arounf 13F
compressor superheat @ 15
liquid termp @ 83F or so. My actual pressures are cloudy going from memory, I rember the subcool to be # 5F
20 t.d across coil
Boat temp 82F Unit ran for 1 hour, nice and quite.
Got a call today that the compressor is noisy,
Turns out on start up after 30 sec of run time, compressor pressure unload as if the unit is overcharged or there is a restriction.
Any thoughts? Did I over charge this puppy? I rember you guys discussing the various ways of charging a captube system.
Perhaps you could give me a refresher course.
Thanks
Bernie

[sparks]

Compressor SH seems low (would think 20deg +) and I would expect to see higher sh at the evap on initial start-up w/ 82deg return, may be overcharged. Don't worry about sc until the space temp cools down a bit.

I charge caps with liquid until I see a noticeable drop in sh 5deg or so then stop. Wait until the system runs a while check temps and check sh at evap after 30min. Charge vapor the rest of the way. After it's been running and space temp is close to satisfying I check sc just to be sure. I'm generally happy with 20-30deg at the compressor and as close to 10-12 at the evap.

JMHO

[Diceman]

I did one boat job, new compressor, used water for cooling like they all do I guess. Maybe condenser ain't so great, full of sea goop or something. Hard to tell till ya go back and put on the gages, could be an overcharge since water temp was low when ya did it, and conditions changed in water temp or something.
At this point it's just a guess till you go back and see.

[toptech]

Thakns for the responses,
Actually, I'm gonna call this guy and make sure he had the pump running!!!!
Either way, I'll stop back this week
Bernie

[dkinz]

Originally posted by toptech
Thakns for the responses,
Actually, I'm gonna call this guy and make sure he had the pump running!!!!

And the strainer is clean, and the through-hull valve is opened. Look for the cooling water exit, typically above the waterline to reduce potential boat-sinking failure points. There should be a good stream of water shooting out. If it exits below the waterline, there is going to be another valve that needs to be opened.

[referjunkie]

did you ever get this running toptech? Another thing for future reference is to check the trigger(cruiseair) or the pump relay(marine air) for the seawater pump.

[R12rules]

Sounds like a neat project.

You didnt mention the temp of both evaps.
Didnt mention the temps once load space was down to design temp. (72F ?)

Does this set up have an accumulator?
Does it have a head pressure water regulating valve?