Seafrost engine driven compressor

[Tcubed66]

Looking for an engine driven compressor for my Sailboat. I purchased boat with compressor removed and mounting plate removed also. Any advice or suggestions?

[Richard Kollmann]

There are three different Auto AC compressors used on those engine driven systems Sanyo 508, Detcel Keeky and Sanden compressors, all fit the same style mounting bracket when used on boat refrigeration. On each application there will be either flared or Oring style compressor connections so if your present lines are designed for flare nuts be sure to order compressor with flared fittings. I would buy the Seafrost mounting bracket and a re- manufactured compressor available from most auto parts stores.

What is left of the old system will need to be flushed out removing all old oil and replaceing refrigerant receiver/filterdryer/sight glass assembly. Replacement parts will contain Ester POE oil compatible with 134a refrigerant.

[Coolerking]

Richard is correct, and I might add that you will want to be sure the TXV's are correct.
You can do this when you remove them to flush the lines.

[Palarran]

There's probably a reason the compressor was removed AND a reason that to the best of my knowledge, no new boats ship with engine driven compressors. In other words, find a different solution.

[Coolerking]

Originally Posted by Palarran

There's probably a reason the compressor was removed AND a reason that to the best of my knowledge, no new boats ship with engine driven compressors. In other words, find a different solution.

You are mistaken.
Engine driven (mechanical) refrigeration is quite popular and makes sense for a small sail boat, we have done lots of dual circuit systems that run on 12/24vdc and an engine driven compressor.
Best of both worlds in my opinion.
Makes it easy to charge batteries, make water, and run refrigeration all at the same time with minimal fuel use.

[Richard Kollmann]

On many boats new or second owner where there is not a sufficient source of electrical power, engine driven refrigeration is the best refrigeration using large eutectic hold over plates. Adequate refrigeration means different things to many boaters. Refrigeration temperatures of 40 degrees F (4 C) will prevent food from becoming dangerous for several days. Freezing temperatures of zero degrees F (-18 C ) can keep many products safe indefinitely.

Coolerking is correct about flow testing of TXV because lack of flow is a cause of compressor failure, On SeaFrost valves their inlet screens are not removable for examination.

Engine driven refrigeration compressor failures most often are caused by excessive Rpm above 1,600. When this compressor is used in auto air conditioning systems where flow low pressure is around 40 to 50 psi delivering good cooling and oil flow to compressor at speeds up to 5,000 Rpm. When this same compressor is used at temperatures below 32 degrees F the refrigerant flow low pressure is anywhere from 3 to a maximum of 15 Psi. Because these compressors need cooling and oil circulation produced by volume of refrigerant flow, low return pressure should be designed to operate at less than 10 Psi. If the design of an engine driven compressor's speed can not be limited to less than 1,600 Rpm the first engagement of compressor clutch each day should be at engine idle speed and held to less than 1,200 Rpm till evaporator stars to cool evaporator plate.

[mvmojo]

We had a SeaFrost engine driven refrigeration on our 42' sailboat which we lived full-time on in the Caribbean for 6 years, 99% of the time at anchor. The freezer compartment had 2 holding plates and the refrigeration compartment had one, all three plumbed in series. We made ice every day in the freezer which stayed at 0 to 3 degrees F. The refrigerator compartment stayed at 37-40 degrees, with the very bottom of it often getting down to 32 (it was about 3' deep). We ran the engine 45 min in the morning and 45 min in the evening for refrigeration and to charge out batteries via a 105 amp alternator. We also had an engine driven water maker pump which ran at the same time so we made electricity, ice and water simultaneously. The system worked quite well for us.

[contrail]

I am also a great fan of the SeaFrost systems, in general. My "small" fridge runs on 12 volts. My "big freezer/fridge" has a dual system, one being the engine driven holding plates and the other being an AC driven system using the same plates. All work exceedingly well. Would hate to get rid of that engine driven system. I run my boat in charter, and although we primarily sail, it's not uncommon for us to make short engine power runs, and I can do a whole lot of the daily refrigerating at those times. I do engage the clutch at low speeds, in general principle. Richard has explained the advantages.

[RaymondR]

Originally Posted by Richard Kollmann

On many boats new or second owner where there is not a sufficient source of electrical power, engine driven refrigeration is the best refrigeration using large eutectic hold over plates. Adequate refrigeration means different things to many boaters. Refrigeration temperatures of 40 degrees F (4 C) will prevent food from becoming dangerous for several days. Freezing temperatures of zero degrees F (-18 C ) can keep many products safe indefinitely.

Coolerking is correct about flow testing of TXV because lack of flow is a cause of compressor failure, On SeaFrost valves their inlet screens are not removable for examination.

Engine driven refrigeration compressor failures most often are caused by excessive Rpm above 1,600. When this compressor is used in auto air conditioning systems where flow low pressure is around 40 to 50 psi delivering good cooling and oil flow to compressor at speeds up to 5,000 Rpm. When this same compressor is used at temperatures below 32 degrees F the refrigerant flow low pressure is anywhere from 3 to a maximum of 15 Psi. Because these compressors need cooling and oil circulation produced by volume of refrigerant flow, low return pressure should be designed to operate at less than 10 Psi. If the design of an engine driven compressor's speed can not be limited to less than 1,600 Rpm the first engagement of compressor clutch each day should be at engine idle speed and held to less than 1,200 Rpm till evaporator stars to cool evaporator plate.

Good point Richard and in view of the problem would you recommend using a different refrigerant than R134 in the engine driven, eutectic systems?

[Richard Kollmann]

Good point Richard and in view of the problem would you recommend using a different refrigerant than R134 in the engine driven, eutectic systems?
__________________

RaymondR, Remember the logistical problems of purchasing refrigerant for a mobile boat refrigeration vary all over the world. In the US the air qualitative standards for 134a refrigerants vary from states to even counties. Oil compatibility is important in refrigerant selected to insure compressor lubricating oil flows mixed in with refrigerant. The standard oil used today in engine driven refrigeration systems is Ester oil (POE) which is compatible with many of the present refrigerants. For most engine driven compressors under 2 ton R134a is available around the world, although those countries signing the Montreal Air quality pact may elect to regulate use of almost every refrigerant.

There are many new blended refrigerants claiming expect-able for use in refrigeration but only the compressor or system manufacture can specify type refrigerant for use in engine driven mobile refrigeration.

[RaymondR]

Hi Richard.

Yeah mate fully aware of the availability and regulation problems related to refrigerants. I changed my system over to a hydrocarbon based refrigerant which is readily available from auto parts stores a couple of years ago.

Many folks predicted that I would blow myself up but I figured the kilograms of gas in the open ended gas stove was going to get me well before the 100 grams or do in the closed system, silver soldered all pipe fridge system would probably get the chance. Both the fridge and myself have survived the hydrocarbons so far.

[Richard Kollmann]

Originally Posted by RaymondR

Hi Richard.

Yeah mate fully aware of the availability and regulation problems related to refrigerants. I changed my system over to a hydrocarbon based refrigerant which is readily available from auto parts stores a couple of years ago.

Many folks predicted that I would blow myself up but I figured the kilograms of gas in the open ended gas stove was going to get me well before the 100 grams or do in the closed system, silver soldered all pipe fridge system would probably get the chance. Both the fridge and myself have survived the hydrocarbons so far.

As long as you understand the risks of using flammable refrigerants. The greatest risk exposure using flammables greater than 8% mixture is liquid refrigerant flow blockage explosion pressures creating a small leak at excessive flash point pressures. Two conditions would be needed to start a fire high pressure switch did not stop compressor and excessive refrigerant volume in this system. Many boat refrigeration systems like SeaFrost engine drive compressors do not have high pressure shutdown switches.

[Dougtiff]

I used to build system's using the HGC Tecumseh or York compressor's when i lived in singapore back in the 80'S, got started doing this because cruiser's would show up with a busted fridge, local mechanic would arrive and leave with no results, [ they were used to BIG walk in stuff], then i bought a boat with a busted fridge, working on the Oil rig's, the Electrician was also the fridge guy, so was given the bible [don't remember title] on refrigeration, big thick book, 90 % not applicable to me, but figured out how to test,evacuate,charge , with lots of mistakes,vented many pound's of R12 to the atmosphere during my learning curve, would make hold over plates using steam trays and the lids with a coil of copper tubbing, couldn't obtain evaporator's, so made my own out of PVC piping, my vacuum pump was an old compressor, good fun, built quite a few for cruiser's.

[Jill on Maya]

This looks to be appropriate thread to ask whether its true that an engine driven fridge compressor (e.g. our Sanden SD5 or SD7 - I can't remember which it is) ideally should be run at least once a month to keep the seals lubricated? A fridge technician recently suggested that leaving the compressor idle (not used) for months at a time shortens the life of the compressor.

[Coolerking]

Anything left sitting on a boat for long periods will suffer.
The sanden style are less prone to issues than say a York, which will leak from the shaft seal if left inactive for a few months.
Use it or lose it!