A/C compressor rebuilds

Marine air was bought out by dometic, same as cruise air. Don't rebuild 20 year old junk, trust me, you will still have junk. Other parts like the condensing unit don't last any longer and you'll have nothing but future problems. Spend the money and buy a complete new unit and have something you don't have to worry about fixing for many years. Also, if the compressor went bad, it most likely sent debris and crap through the lines and condenser. If it's a shorter run, replace the lines also. Then you can fix something and not have to worry about it for a very long time.

Unit 3 may be the heat exchanging coil and it's leaking into the saltwater side. You need to fix the leak, or the system loses the oil in it with the leak and you keep adding freon but no oil charge and eventually the compressor fries. If this is the unit with the bad compressor and you have no visible oil leaks/stains after adding so much freon just change the whole unit.

I don't think you need to pull headliners or anything like that. The controll panels look very similar and probably the smx 3 panels would work, with your old panels wiring. It probably uses the telephone jack cable connections. Or you could attach a pull cord to your old wiring, pull it through and pull the new back if they didn't wire tie the heck out of it.

The drop-in replacement for your compressor is a Tecumseh AWG5524EXN that sells for about $600 at places like Johnstone Supply or other HVAC equipment suppliers.

Or even cheaper online: http://controlscentral.com/eCatalog...96/ProductID/410243/PageIndex/10/Default.aspx

Job Security comes to mind.

If the OP has had to keep adding freon on an often basis, he has a pretty large leak somewhere. Adding a new compressor to a system where either the heat exchanging pipe has a leak or the condensor has a leak, will just kill the new compressor as well. Also when a Compressor goes bad, most of the time it sends debris through the entire system, the lines should be evacuated thoroughly. At 20 years old, you're just spending good money after bad, the unit has seen it's useful expected life. Most people wouldn't think of putting a new compressor on a 20 year old central a/c system on their house, so why would someone do that on a yacht with a unit that's dealing with a salty air and saltwater environment? Not to mention R22 isn't $10 lb anymore....not even close......

If you're freon pressures are too high, it will cause the compressor to use more amps and pop the breaker or damage the compressor (as will not enough of an oil charge or very low freon). This happens sometimes if the unit was charged during the winter and the water temp was 10F lower. A low water flow (raw water) will also kill compressors also in a short amount of time.

I don't know. I manage 10 different yachts +/-. I can count on 1 hand, how many times I've had an a/c tech out in the last 5 years between all 10 boats. Granted I change a/c raw water pumps myself.

It should in both cases. But it takes 3 tries of running the compressor for 10-30 seconds (depending on how the board is setup) before the board shuts the unit down on low pressure and LP flashes on the screen.

If the unit has higher pressure than what it should operate at, but is just below the high pressure cut-off switch, the unit will use more amps (sometimes kicking the circuit breaker off like you're experiencing especially if the breaker is close to the amps used or is getting weak) and it will also tax the compressor. There is some variance between what the unit should run at and what the high pressure cutoff switch is at to allow for raw water temperature fluctuation which influences the high pressure side a great deal.

All newer units NOW have low pressure switches. Most all have hp switches.
I never could figure out why many pieces of equip was sold with out a LP switch, guessing, the mfg wanted to sell more equipment.
Yes, low pressure switches make a lot of sense. I install them on every one of my a/c services.

Did the tech give a very specific cause ? Just not Bad Compressor.

When a breaker kicks it's because of a overload.. Only 2 things internally to a compressor that would cause this . First the insulation on the wiring inside is breaking down or a dead short or a bearing causing friction making the load increase.
Your tech should give you very accurate ohms readings between the start/run/common poles compared to the factory specs. You can also check with a amp meter For for running load draw....Easy to check youself with a multimeter....

The second cause is the compressor has mechanical issues,then its a seized rotor or piston is found a amp meter will read the LRA (locked rotor amps) of the compressor .

There are many external resons a compressor won't start or runs and shuts off.. From to low or to high of a charge to someone installed the wrong capacitor size. And Many More..

That sound very much like a locked rotor current. Look the dataplate on the compressor itself and you should find a notation that looks something like LRA xx.x

Yours might be 80A

In the first picture in this thread you can clearly see that the LRA is 61.0 amps.
That means that compressor can not draw more than 61 amps under any condition.

Since you said it runs for a time you need to start tracking down the problem. First google the compressor model number on the metal tag and under electrical specs they will give RLA (running load amps) or a FLA (full load amps). Also get the factory spec ohms readings for the 3 poles,start, run,& common. Plus get the microfared or uF(they mean the same) size of the capacitor.You'll need this info to diagnose your problem. Could be a bad run capacitor,or contactor as well as a failing compressor. You need to go down a fault tree and I start with the electrics. I absoulty hate people who just keep changing parts until they fix it or right from the start tell you to scrap it, when the problem may only be minor and repaired .