Grunert Passagemaker Refrigeration not cooling

[gsholz]

I'm new to cold plate refrigeration and would appreciate feedback. We have the Grunert Passagemaker holding plate system with two refrigerators and one freezer. The system is AC-powered and has both air and water cooled condensers operating when the unit is on. The compressor is hermetically sealed.

The system is operating but it is not pulling down the cold plates as I think it should. I understand running it for a couple of hours in the morning and evening should keep the cold plates frozen. I have run it for days without the system cycling off. When I look at the evaporators/cold plates, only the first third or so is frosted after running several hours. I understand the cold plates should be completely frosted.

I suspect the refrigerant charge needs to be topped off or the expansion valves need to be adjusted (opened further). Since none of the cold plates really freeze, I suspect the culprit is low refrigerant charge. Anything else I should be looking at?

 

[Lucky Chucky]

Captain,

We had a similar issue a few years ago. Two plates we leaking. We were able to weld one and replaced the other. We recharged the refrigerant 404a, replaced the filter drier, hose clamps, fittings and vacuum pump oil.

Presently, it works great and we only need to run the deep freezer for 2 hours every other day or two while cruising.

~Lucky Chcuky

 

[Giggitoni]

You should have an in-line sight gauge. Usually a round glass cover facing up. If you see bubbles circulating past the sight gauge when the system is running, you need a coolant recharge. I recently removed my 33-year old cold plate system and replaced it with a DC system utilizing my existing ice boxes.

 

[gerryhebear]

I also have the Grunert cold plate system with 2 units (one fridge and a freezer) The compressor won't start up and trips the breaker. Its a 3/4 HP Model 75CDW unit. Would appreciate more info on the 12V install. I would like to keep the box units as you did if possible. Ideally I'd just like to change out the compressor but am not able to find a substitute.

 

[DCDC]

We also have the same Grunert cold plates/refrigerator/freezer system. Working well so far, but have been thinking about what it would take to replace the compressor.

 

[gsholz]

I'll check the sight glass for bubbles and measure the temps in/out of the condenser next time I'm at the boat. One challenge will be finding a refrigeration tech that is willing to come to the boat (Victoria area, BC).

 

[Giggitoni]

I'll check the sight glass for bubbles and measure the temps in/out of the condenser next time I'm at the boat. One challenge will be finding a refrigeration tech that is willing to come to the boat (Victoria area, BC).

I believe that any refer tech should be able to check and recharge your system, if necessary. These are similar systems used on applications other than marine. IOW, a good refrigeration tech will be able to help...may not like cramped quarters, though!

 

[BrisHamish]

To the OP,

I have just made a similar post on a similar thread related to the Gruneret system.

Based on what you have posted, I suspect you have a refrigerant leak. Giggitoni is correct, there is a site gauge near the compressor which will (likely) be full of bubbles - as mine was when the system had a leak - it should not be so).

Mine developed a leak, and the compressor generally looked old/tired (my boat is a 2006 build), so I had the whole compressor rebuilt/refurbished and resprayed and a fresh charge of R12 refrigerant put in. Cost in Australia was AUD3.5K.

The system now works like a champion. Plates freeze over within a couple of hours, once they are down to temp they stay down for a long time before the system needs to come on again.

Find a local tech who knows the Grunert system, and I think it will transpire that the tech will quickly find the fault and it can be pretty easily remedied.

And once it is fixed, that system works a treat.

Hamish.