Do refrigerators explode? Because I think mine may have done.

[limbodog]

Hiya,

Hopefully I'm in an appropriate sub-forum for this question. Apologies if not.

Anyway, my 1985 hunter 40 has two fridges. It's got a cube fridge in a bulkhead cubby that appears custom built for it, and it's got an under-counter ice chest refrigerator that may be aftermarket.

Chilling out the other day I heard a loud bang that sounded like something hitting wood hard. I scoured my boat for an hour looking for damage, but found nothing. A couple days later I noticed the ice-box's 110 AC breaker was thrown. Flicked it on and it sparked and was thrown again. Yeah, don't do that, I know.

My guess is that a hose popped in the cabinet under the galley sink where the "Marine Air System" refrigerator unit is located and that was the bang. Losing coolant means losing lubricant for the compressor. I think it ran for a bit and then seized and I didn't notice (or wasn't home at the time) and that's why the breaker is thrown, it's trying to turn a seized motor.

I'm a newbie tho', and that's a guess.

In any case, the cube fridge is also non-functional and also 33 years old. So now I'm without refrigeration. You know how they say "this happened at the worst possible time!"? This is the opposite of that. It could not have happened at a better time, because the air outside my boat is cold enough to chill anything I need preserved (Boston winters for the win).

So I'm here looking for a sort of general help/discussion about fridges.

Do they blow up like that? Do they throw breakers when they seize? Anyone have experience replacing them (either the cooling plate kind or the cube fridge kind) who can offer advice, tips, links, recipes?

Attaching pic of under counter unit controller label: https://imgur.com/a/MB3f8rI
Apparently that is "Grunert Docksider" brand fridge (at least I think it's a Docksider)

And a crappy video I took of the unit: https://imgur.com/a/NFFohpQ

Thank you in advance.

 

[JamesG161]

Two parts...
1) Cooling water pump
2) Grunert compressor

Both take 120-VAC

The noise could have been either one of the motors for them.
Jim...

 

[limbodog]

I just learned about LRA (locked rotor amps) which means if the motor can't spin, the system will draw X number of amps. For the docksider that's 40 AMPs (at least for the newest version) which should be plenty enough to trip the breaker.

Educational!

 

[JamesG161]

Get the Grunert Model number off the Black plate, call their number shown on picture and ask for Grunert technician. He will tell you if there is a Grunert replacement.

Grunert is a brand name for Marine Airree or now Dometic.

LRA means the maximum Amps to Start the Compressor motor. The Start winding takes that on start up. It has a start relay and capacitor to achieve the 40 amps. It is NOT the run Amp, don't mix them up.
Jim...

 

[limbodog]

Yup, not the run AMP, if it were it wouldn't have been running at all, i'm only on a 30 AMP 110VAC line. But I figure it would explain the breaker.

Not sure I can access the back plate easily, but it looks identical to the docksider and none of their other models look similar, so I'm confident for now at least (enough for me to start talking to a Grunert person anyway).

Wondering if it will be easier to replace with a new docksider or just to put in any system. It doesn't look like much can be saved from the original installation. All pipes and hoses will need to be replaced along with the unit. *maybe* I can save the plate inside the ice box, but I doubt that'd save me much if anything.

The phone numbers on the panel are for the maker of the controller, not the actual fridge. (Micro-air controllers) and I think the number is old anyway.https://www.Marinespecialists.com

 

[JamesG161]

The run Amps for the water pump on my Grunert model [not yours] is 4 amps.

The BLACK Plate....
Shown on your video.
Or any other spot you can get the Grunert Model number.

_____
My Grunert bit the dust and yes the Hold Over Plates are important.
There are NOT cheap, since they are basically custom made.

My replacement was supposed to cost ≈$5000, I fixed mine for ≈$1200.
Why?
It was just the compressor.

Your unit appears to have surface damage from the cooling water leaks and corrosion on surface.
Water hoses are cheap and needed for new unit too.
Jim...

 

[dlochner]

Grunnert uses large holding plates to keep the box cool. I have one and I really like it. If it ever fails I will replace with a like kind. The advantage to the large plates is that compressor only runs a couple of times a day for under 30 minutes. It can also be set up to run only when connected to shore power or when the engine is running. Or the relays can be bypassed so it runs off batteries when ever it needs to, but I'm not if this is a factory approved method.

Check the cooling water pump. I seem to go through those too frequently.

 

[JamesG161]

If it ever fails I will replace with a like kind

I decided to just replace the Tecumseh® compressor since the expansion valves have to match the refrigerant.
Amazoom listed it at $950, I got mine for $425 from my AC expert.
We Megged the compressor and it had a dead short.

The rest of my Grunert was is great condition.

I forgot to set the thermostat in the freezer on start up of new unit.
Froze all of my beer SOLID in 18 hrs.

Jim...

 

[limbodog]

https://shop.dometic.com/store/dometic/home Looks like Dometic who owns Grunert now only sells standalone coolers. That's not good news for me.

$5000 is a bit expensive to replace. Yowzers. @JamesG161 I will go back and get a good image of the black plate when I get home.

My unit was probably not well ventilated like it was supposed to be. Corrosion all over it. It only had access to the air in the bilge from below.

If it's possible to replace just the compressor, that'd be a nice bonus. Tho' if it's going to be thousands to repair it may be better to replace the cube fridge first. That'll also be at least a thousand, but hopefully requiring a lot less to install as it's pretty self-contained.

 

[limbodog]

Frozen beer? Sounds like a new market niche.

 

[dlochner]

Those Grunnert cold plates get really cold. I haven't had frozen beer, but I did freeze dinner and the orange juice!

 

[dlochner]

https://shop.dometic.com/store/dometic/home Looks like Dometic who owns Grunert now only sells standalone coolers. That's not good news for me.

$5000 is a bit expensive to replace. Yowzers. @JamesG161 I will go back and get a good image of the black plate when I get home.

My unit was probably not well ventilated like it was supposed to be. Corrosion all over it. It only had access to the air in the bilge from below.

If it's possible to replace just the compressor, that'd be a nice bonus. Tho' if it's going to be thousands to repair it may be better to replace the cube fridge first. That'll also be at least a thousand, but hopefully requiring a lot less to install as it's pretty self-contained.

try this link: http://www.marinespecialists.com

 

[JamesG161]

The Hold Over Plates contain a eutectic solution like "Blue Ice Refreezing Blocks". These plates freeze and hold over freezing like the Blue Ice. Thus you can turn off the power and the plates give back there COLD to keep your box cool for hours without power.

Mine last for about 20 hours on a box that the contents are already cold.

$5000 is a bit expensive to replace.

Yeah I didn't budget that.
______

I seem to go through those too frequently.

Mine is a Marsh Pump.
It was perfectly installed to be below the water line and self priming. I disconnected the compressor power and ran my Marsh alone with the cleaned out water lines. Shot a stream about 8 inches out of the discharge port.
I would think the only thing that could go bad would be the Pump Head itself.
Jim...

 

[limbodog]

try this link: http://www.marinespecialists.com

I have that site. I was hoping that they had the docksider manual, even for the newest model, but no dice. They seem to have manuals for everything else tho'.

 

[Gunni]

Who runs a raw-water cooled refrigeration system in Boston in the winter? It freezes up and stops pumping. Drain and winterize that thing. Go buy yourself a 110 dorm refrigerator and a cooler for the deck. You can assess the damage when the water warms.

 

[JamesG161]

Go buy yourself a 110 dorm refrigerator

If the frig is inside the boat, it will warm the interior too.
Jim...

 

[limbodog]

Interior of the boat has never been below 42ºf, so I doubt it froze. But yeah, maybe a cheap dorm fridge is an acceptable replacement for now for the $1200 marine fridge in the short term.

 

[Gunni]

The raw water freezes where it meets the refrigerant mixer on the condenser coil. Boom, no flow. Doesn’t sound like you have a separate motor controller to manage LRA loads. These things are complicated.

 

[JamesG161]

Interior of the boat has never been below 42ºf

But...
The overboard discharge port can freeze up!
That happened to me in the deep south, last winter.

Also all water lines must be kept from freezing when the water pump shuts down.
Jim...

 

[Stu Jackson]

But yeah, maybe a cheap dorm fridge is an acceptable replacement for now for the $1200 marine fridge in the short term.

Here's what a very creative person did:

http://www.cruisersforum.com/forums/f115/sailorchic34s-new-fridge-180007.html