[aeventyr60]

New to me system, clutch engages on compressor, expansion valve on the inside of the fridge gets frosty, the plates not so much, seems like the tube leading into the holding plates are not getting very cold either. Your guidance please?

I ran the system for an hour this afternoon, the system has not been run for a few weeks.

 

[deniseO30]

Wet your finger tip if it sticks to the evap it's cold enough. (or use a infrared hand held thermometer) It takes awhile for a system to start perking after being off for a long time, it may need recharge but that means knowing what kind and how much refrigerant. I'm guessing R-12 or R-134. I do know engine driven systems on boats are very very large compared to the little 12 volt wonders many of us have. Does the engine mount compressor look like the old type open type or something like the newer automotive types?

 

[aeventyr60]

No finger sticking to the plates going on here. Warm. The plates are huge and are marked as O degrees. Will assume celsius as am in that part of the world. I'll give it a look this AM, think a tecumseh compressor with 134A.

 

[ReefMagnet]

Most marine refrigeration guys will tell you the best thing you can do with engine driven refrigeration is toss it out. I'd take a stab that you are either low on refrigerant or, much less likely, your eutectic fluid is low. You should also check that your condenser is being cooled properly as well.

 

[deniseO30]

Not a guy here but yes, it's pretty old tech stuff. If you must check the refrigerant, the low pressure should be around 5 lbs. Trouble is ,when theses types get low, the low pressure will go to a vacuum which will let air in the system if a gauge hose is connected. This why most techs will connect to the high pressure side first.

 

[aeventyr60]

Seafrost system and compressor. All new. Gauges on boat but no R134a. Will run in a few minutes and see what happens today

 

[deniseO30]

Like this?

Engine Drive

Please make sure the condenser is getting good water flow, Look for traces of oil on all the mechanical connections. I can't find the refrigerant weight needed since I don't have model numbers. You must have it if it's all new.

If it is low on 134 and you need to add, it we first want to know if it has "service valves" on the compressor. or just schrader access. You will want to connect the low (blue) when the system is off so air doesn't draw in. Then you want to purge the air from the hoses to the tank that is setting on an "electronic scale" made for such purposes. It's easier to let it all out evacuate, then start with a new weighed in charge.
hope this helps!

 

[aeventyr60]

Thanks Denise!

I found the manual and RTFM'd. Leak checked with the ol soapy water routine, maybe small leak on one of the swagelock fittings at thr bottom of the condenser. Found the sight glass hard to read, as it is just a small, less then a dime sized piece of glass at the top of the RFD unit. Would try and gass it up myself, but the R 134a is only sold in 1o Kg. cans. The weight of the refrigerant is about 27 ounces, 2 small cans of the automotive style recharge cans. Sea Frost actually recommends not using large canisters as it results in overfilling the unit. So will find the reefer dude.....who is a really busy dude...we all like are beer cold!

 

[aeventyr60]

The reefer dude appeared this AM. System check, still full of gas, looks like the expansion valve is plugged or not working properly...more on the story later this week. Thanks for your replies.

 

[deniseO30]

TXVs are great when they work, moistue will plug em, good luck!

 

[Rocky Mountain Breeze]

To check for moisture in the system when the TXV won't feed use a small hand torch to warm the valve body. If ice is blocking the orifice the refrigerant will begin to flow when you heat the valve but will quickly stop flowing once the heat is removed. If you have moisture in the system you will need to remove the charge, change the filter drier, evacuate and recharge with fresh refrigerant. The moisture will stay in the system oil so a deep vacuum is required and heating the compressor with a lamp or other low intensity heat source while the vacuum pump is on will help a lot.

If you do not understand the refrigeration cycle, the proper procedure for purging hoses, and understand how to read a pressure-temperature chart please don't try repairs yourself as it is as dangerous as playing Russian Roulette with a revolver.

 

[aeventyr60]

The rest of the story...the expansion valves are from Danfoss. By removing the cap, one can see an adjusting screw, in or out allows more gas to flow through the system. Several different inserts for the valve are available from Danfoss, these are marked, O1, O2, 03. This one was an 01, by backing off the screw adjustment, more gas allowed thru the tubes, and into the plates, and wallah, cold plates, which equal cold beer..simple fix...for about 65 bucks, learn something new out here every day.