Portable Electric Freezer

[Capt. Rodbone]

Wife and I are about 1,500 miles into our Great Loop on our 78 Grand Banks. Classic. We don’t have nor want to install an inverter. We have a Northern Lights Lugger 753K generator. We are finding that our “freezer” only keeps things frozen when we are connected to shore power. When running our generator, even at regular and long intervals we are having to deal with what just thawed out controlling our meal choices.
It’s not as if we have “space galore” but I’m wondering if we should invest in a freezer that’s portable and 110 AC. I’m no electrician, which is probably evident. The misses says it would get the same amount of juice the freezer does, hence we’d face the same problem. I’m hopeful that something not 45 years old with newer technology would be more efficient.
If I’m correct on that, I’m hoping that some of you will reply with ‘ we had the same issue and bought an ‘XYZ’ and it’s made all the difference in the world”.

 

[tiltrider1]

This does not make sense. What voltage is your generator putting out? Is your freezer some how not connected to your generator? Is your freezer being affected by the heat the generator creates?

A NL generator should be just as good and sometimes better than shore power.

 

[Greg QS]

I'm not familiar with the freezer in the GB . Is it a stand alone plug in, a split system with freezer plate?


If your generator is operating properly there should be no difference between shore power and genset. Leads me to belive your suffering from a power problem with the genset or how the freezer is getting power.

Is the freezer 110 and 12 volt. If so you may be running on the 12 volt automatically. I have an ac/dc freezer and it defiantly works better on ac.

I replaced it with a chest freezer from home depot, works fine on the genset and the inverter system.

I would suggest first testing the voltage at the plug at the freezer on shore power, then on genset. See if there is a difference in voltage. Low voltage will cause a problem like this.

If genset is working properly, it may just be time to replace the unit.

If its a split system, Where is the unit. My split refrigerator is in the engine room and has a secondary pump on a thermostat. When the ER heats up It turns a water cooling circuit for the ac. Are you suffering from a heat build up and the freezer cannot transfer out the heat.

 

[Choices]

Welcome to the Grunert system. The holding plate technology was state of the art, 30 plus years ago.

I know three GB boats converting their refrigeration system within the year. The chose the Vitrifrigo stainless steel drawer option, and both changes can be done in a weekend. About $3k per unit. Pretty much plug and play.

First, you can buy a portable 12vdc/120vac frig/freezer set up by several manufacturers. I have a large Whynter unit, and a smaller Engels.

The Whynter is completely programmable for each compartment. The Engels has one compartment for any temperature. The Whynter uses Danfoss technology. My Wynter is five years old, the Engel around fifteen.

Both units are under a grand, and can be carried loaded and plugged into a cigarette lighter. This is how we move food around. They easily run off solar.

I gutted the Grunert system and went with Danfoss compressors. It was a weekend job. Now my freezer has hit -16!. It is roughly a grand for a frig or freezer package.

Go to my blog, grandbankschoices, and dig around to find the post.

My system is now 12vdc, so quiet you can not hear it, and works flawlessly. The only thing we run the generator for is the A/C and occasionally battery charger.

Don't believe you can fix the old system. There is no reason to repair it when for the same cost you can upgrade it. You keep your doors and hardware.

Any questions PM me and I will call you and walk you through it. Best upgrade we have done to the boat.

 

[Choices]

My boat is in Mobile, if you want to come check out my installation.

 

[mvweebles]

Can't help with why your freezer isn't energized by generator power, but maybe a 12vdc freezer would help? Not a specific recommendation, but something like this:

Alpicool K25 Portable Freezer,12 Volt Car Refrigerator, 26 Quart (25 Liter) Fast Cooling 12V Car Fridge Freezer -4℉~68℉, Car Cooler, 12/24V DC and 100-240V AC for Outdoor, Camping, RV, Truck, Boat https://a.co/d/4b95oRn

 

[Choices]

The Grunert system was designed to freeze the holding plate inside the cabinet rather quickly, an hour or less, and the solution to stay frozen for a long period, then repeat.

Problems are usually leaking refrigerant, leaking medium, etc.

The system is hard to balance, and parts hard to find. They are a power hog. No one wants to work on them, and labor rates reflect it.

It works best on shore power because it runs continuously, and there is no heat generated by the engine or genset. You are running a genset to try and keep food frozen.

The new stuff is all DC powered, with options for 120vac if available. Pretty slick.

 

[Max1]

I switched my 110V bar fridge consuming 75A per day to a 12/24V DC that is twice the size but uses uses only 50A/day.

The company markets these 12/24V Fridges(and freezers) as "Solar Fridges", though there is nothing uniquely special that makes them "Solar". Near as I can tell, the name is just a marketing gimmick to sell to the off-griders that are powering their homes via solar.

I am very pleased with the performance of my DC fridge, its performance when I tested it at home was better than the marketed specifications. This is my thread where I show my test data.
https://www.trawlerforum.com/forums/showpost.php?p=1153544&postcount=145

I see Unique makes a 12/24V chest freezer with excellent specifications, about 52A(@12V) drawn from your batteries in 24 hours.
Here is the link if you are interested:
https://uniqueappliances.com/product/off-grid-9-3-cu-ft-solar-powered-dc-chest-freezer/

 

[SteveK]

The OP freezer works when plugged into shore power, but not from the generator. The generator supply needs to be tested at source for output and if good then where the line arrives in the distribution panel. Then after the switch that passes power etc.
Why can't that be done before a new freezer is purchased?

If gen is outputting at source, great, the issue is down the line.

 

[Jc180]

Wife and I are about 1,500 miles into our Great Loop on our 78 Grand Banks. Classic. We don’t have nor want to install an inverter. We have a Northern Lights Lugger 753K generator. We are finding that our “freezer” only keeps things frozen when we are connected to shore power. When running our generator, even at regular and long intervals we are having to deal with what just thawed out controlling our meal choices.
It’s not as if we have “space galore” but I’m wondering if we should invest in a freezer that’s portable and 110 AC. I’m no electrician, which is probably evident. The misses says it would get the same amount of juice the freezer does, hence we’d face the same problem. I’m hopeful that something not 45 years old with newer technology would be more efficient.
If I’m correct on that, I’m hoping that some of you will reply with ‘ we had the same issue and bought an ‘XYZ’ and it’s made all the difference in the world”.

1. Glad to see you’ve made great progress making your way south!
2. Suspect your gen set IS powering freezer. You can do a simple test to verify. Plug something else in same outlet to check when gen running.
3. We have a portable Engle fridge freezer. Probably one of the more efficient on the market. It can be powered from 12VDC or 120VAC. In fridge mode, compressor cycles on off frequently, maybe on 25% of the time. However, in freezer mode, compressor cycles much less, probably running 80% of the time or more. Compressor draws conservatively 4 amps DC. When under way, or at anchor, we run it on 12VDC (the engine alternator keeps it powered via the house bank when under way). Even on freeze mode, if we turn off at night when we are at anchor to conserve battery, it is still frozen in morning. Then turn back on in morning to be powered from battery. Highly recommend the Engle.
4. Back to your case. You don’t say what duration your “long interval” gen runs are. But suspect even two or three hours twice a day would be insufficient to keep freezer frozen. And will get worse as ambient air temps increase.
5. In summary, think an Engle or perhaps similar, would solve your problem. You will need to be attentive to battery charging though. Another topic for another day.

 

[Capt.Will]

We have a Grunert fridge and freezer on our 33 year old GB,the fridge works great but the freezer is u/s.So we purchased a unique 120 litre ac/dc fridge freezer and it has been
flawless for over three years now,well recommended and came with a 120v solar system.

 

[C lectric]

I agree about find out what the output voltage of the generator is when running with the fridge operating.
Check at the generator and then at the plug in for the fridge/freezer.
Without knowing what voltage is being produced you are flying blind and could easily err and replace something that is functioning but not fix the problem.

Our fridge and freezer , freezer on back deck, are both cooled by the Danfoss BD35 and do quite well. But I had problems with the freezer which I traced to the power plug I used. A cigarette lighter receptacle/plug. It simply was not up to the job, specifics don't matter. A change to a heavier duty twist lock type plug/receptacle intended for either small electric O/B engines or downriggers made a world of difference.

The main point is find out if the proper voltage is getting to the cooling unit.

 

[tiltrider1]

I have a DC powered Sea Breeze that is 30 years old and freezes to sub 0 degrees. However, I am not suggesting that the OP needs to buy a Sea Breeze. Instead, he should perform some diagnostic work to determine why his adequately performing fridge fails to preform under generator. Seams like so many people only have one answer to boat problems, spend more money!

 

[Choices]

On my GB36 the problem was not the generator, but the refrigeration system was so old, the heat of the generator and engine knocked the ambient up enough the compressor could not get there. Like a 70 degree Delta. You raise the 90 ambient 20 degrees, now 30 freezing is 40+.

Mine was air cooled in engine room. Piping in engine room. On a hundred degree day who knows what it was.

On utility power the only heat generation was the compressor.

 

[SteveK]

@Clectric
The plug where the freezer plugs in works fine for shore power, so it does work.
Need to check the load side of the generator switchover at the panel, after confirming line side matches generator output at generator.

 

[BruceK]

OP hasn`t said he has a cold plate system, but Choices points to that as likely in a GB.
I used notice that the compressor driven cold plate system in my IG, supporting separate fridge and freezer, pulled down faster on shorepower than genset power.Maybe Choices is right on that. A friend said the mains electricity supply was better, no idea why.
There was a valve in the line to the freezer which could regulate "cold supply" between the 2 cabinets, if you have one it could be worth inspecting. My IG also had the compressor in the ER, where it inevitably got hot and was usually in use with boat parked. Saving grace was the ER air extractor sat right above the compressor unit. ? happy coincidence or good design but if I ran that it helped, as did opening the ER entry hatch. Battery charger supplied the amps, generator being on already.

 

[Southern Boater]

Welcome to the Grunert system. The holding plate technology was state of the art, 30 plus years ago.

I know three GB boats converting their refrigeration system within the year. The chose the Vitrifrigo stainless steel drawer option, and both changes can be done in a weekend. About $3k per unit. Pretty much plug and play.

First, you can buy a portable 12vdc/120vac frig/freezer set up by several manufacturers. I have a large Whynter unit, and a smaller Engels.

The Whynter is completely programmable for each compartment. The Engels has one compartment for any temperature. The Whynter uses Danfoss technology. My Wynter is five years old, the Engel around fifteen.

Both units are under a grand, and can be carried loaded and plugged into a cigarette lighter. This is how we move food around. They easily run off solar.

I gutted the Grunert system and went with Danfoss compressors. It was a weekend job. Now my freezer has hit -16!. It is roughly a grand for a frig or freezer package.

Go to my blog, grandbankschoices, and dig around to find the post.

My system is now 12vdc, so quiet you can not hear it, and works flawlessly. The only thing we run the generator for is the A/C and occasionally battery charger.

Don't believe you can fix the old system. There is no reason to repair it when for the same cost you can upgrade it. You keep your doors and hardware.

Any questions PM me and I will call you and walk you through it. Best upgrade we have done to the boat.

Couldn’t agree more regarding wasting money on servicing the old eutectic system.
My last servicing bill amounted to the equivalent of a new tech fridge system that won’t require a clueless young refrigeration “mechanic” to come down to the boat and try to learn the old school system on my dollars.
Next time it fails, it goes in the bin and new tech will be installed, and break the cycle of dependency on outside assistance, whatever form that takes.

 

[Irish Rambler]

The way I got around that problem was to buy a standard larder fridge (no icebox) and a separate freezer, we have no room for a combined unit.
Both are fitted with a Danfoss Secop BD35 compressor and both are fitted with a Danfoss Secop 12v changeover unit.
Once you disconnect from shore power they both automatically change over to 12 volt and your alternators power them as you cruise.
Our battery capacity is such that we can sit for 3 days without shore/alternator power.
The company we bought the fridge off was Vitrifrigo and the freezer was from Inlander Low Voltage in Walsall, England. www.inlander@btconnect.com

 

[Bmarler]

I prefer to use a stand alone top loading chest freezer. It’ll hold overnight without power easily. Keep it at zero or colder. Use the inside freezer for the next day or twos meals, keep the rest in the chest freezer. Just a cheap energy star rated unit. Put a waterproof cover over it. Replace as needed.

 

[Choices]

I had forgotten about the chest freezer. A lot of GB Europa had them on the back deck under cover.

Those can be had cheap, and you just replace them every few years, or gut them and use those components to retrofit.

 

[C lectric]

Capt.Rodbone

You say the freezer works well when on shore power. Then won't work properly on generator power.
There is a hitch in the wiring from the generator OR
the generator is not producing the correct voltage.

There is another possibility and that is the generator is not producing 60Hz.
I am not a generator mechanic but I have seen exactly this kind of problem with this kind of result, not just for freezers..

Frequency and voltage are intimately interconnected. If the frequency is low the voltage will be low which means the freezer may not be able to cool properly. THe motor will run to slowly if frequency is off.
It cannot get the needed power which will eventually damage the motor if low enough, long enough.

To check this you will need a DMM that can read frequency in addition to voltages. Low voltage can have other sources of low but if the frequency is low IT WILL produce low voltage.

If you don't have a DDM that is capable of reading this they are not the high price items they used to be. Or ask around the people you meet. Likely there will be an electrical type who could check this for you.

If it is low frequency then there is usually an adjustment screw on the generator control linkage which may be in the manual.


I just remembered another method I have used to check for low frequency.

Plug the freezer into the generator supply and let it get going.
Then plug it into the shore power supply as quickly as you can.
Listen very carefully for a change in sound as in a slight speed up.
If you hear a speed up then the generator frequency is low.
I used this method years ago to deal with my , but different setup.

I had a dual voltage fridge and over the years the electronic control bit had sagged and that is how I twigged.

Once I realized, I was then able to readjust the frequency and viola, the fridge work properly. TO boot I noticed that as I raised the frequency the amp draw dropped and of course the motor sped up.

To emphasize how important freq. is in my case the freq. had only dropped about 4 or 5 Hz. Doesn't sound like much but to AC driven devices it is a lot.

Do this last test at least and good luck.