Converting engine driven freezer to battery

[fliti]

I had two useful responses to this from the Liveaboards. Just in case someone missed it there..I have a 2003 Beneteau 50, whose original owner appeared to regard the presence of mast and sails as a bit of an irrelevance, bless him. Huge twin alternators and an engine belt driven freezer suggest he would have been better with a power boat. Now in the Caribbean, I really need that freezer but running the engine only to get the hook up or down is not going to even slightly cool the huge holding plate. I'm no engineer but there's a big lump of kit run off a belt from the engine that I suppose should be a compressor. Hoses lead from there to a cylinder of about 1 1/2 litre capacity mounted in the engine compartment and that must in turn be connected to the holding plate. No sign of any other kit items except a thermostat. The holding plate is in a decent size, top opening, well insulated freezer box. Much faded labelling suggest it's a Frigoboat set-up. On the cylinder, I can just about read D3000. Can anyone tell me how I might convert the whole contraption to run off my batteries, please? What, if any, bits of the kit will be re-usable?

 

[Plevier]

I did a conversion like this but only for a fridge not freezer.
I had to scrap all of it and go with a kit of new parts something like this http://www.marinesuperstore.com/item/99176952/waeco-cu55-vd01-cooling-kit-box (there are various sizes of compressor and evaporator). Worked well.
You can't reuse the holding plate with a battery driven compressor.
I can't advise you about a freezer. Suggest worth looking at Waeco's and Frigoboats websites.

 

[fliti]

One of the responses in the Liveaboard Forum suggested retaining the engine driven setup as a supplement to use when the engine is running but set up a parellel battery driven compressor plus evaporator as Troubadour proposes. Unless someone knows a cunning way to run the holding plate off a battery driven compressor, this sounds like the way to go. Space permits inside the freezer box for both the holding plate and an evaporator but outside, I wonder if the same battery driven compressor can be used for both the fridge and the freezer? I met a french man who had this but his compressor was a big 220v job run off an inverter drawing 40-50 amps, although he claimed only for two hours per day. Perhaps it would still be better to keep the systems separate to ensure backup if one failed? Could I share the keel cooler, though?

 

[Plevier]

I really don't think you can use the holding plate with a battery driven compressor. It's designed to take a very high power input for a relatively short period and store the cold in the latent heat of a phase change medium for gradual release. A normal battery driven unit just operates the evaporator as and when required like a fridge at home.
Your freezer must be large if you have room for both! I couldn't have done that and the engine driven compressor was duff anyway.

 

[Paddingtonbear]

If the freezer is that big it will need considerable battery power and whilst you seem to have sufficient alternator output you should certainly do a power audit to check that you have sufficient battery power, which I doubt.

 

[rob2]

Suggest you contact Penguin Refrigeration Engineering http://www.penguinfrigo.co.uk/. They supply Frigoboat equipment, although I think they have moved somewhat upmarket. The old systems were supplied as a kit of parts - compressor, holding plates, hoses, condenser - each fitted with self-sealing connectors and pre-charged with gas and oil so that the final charge matched the assembled system. I believe the majority of the compressors were Sanden 5 cylinder automotive aircon units, they're pretty much cylindrical with an electro-mechanical clutch on the drive pulley to engage the compressor or freewheel as required.

Penguin should be able to advise you whether there is a suitable electric compressor that you could substitute. You'll need to find out whether your old system is using a currently available refrigerant - changing it can cause complications although, again, they can advise you on this. The labels on the system should indicate which refrigerant it is filled with.

Rob.