How Long will Norcold Run

Posted this by accident in the General forum about Irma. My questions do concern Irma but not the track.

Questions:

About how long will 8 new AGM 6 volt batteries on a Magnum Inverter keep a Norcold double door refrigerator/freezer going if it is the only 110v load?

Would it be better to run the refer off 12 volts instead?

We are in Riviera Dunes Marina in Palmetto...south of Tampa Bay...and just found out that they cutting power at noon tomorrow. Not being kicked out per se. Can run the genny and stay if we wish.

Figure it will consume 6amps and run 50% of the time, so an average of 3amps x 24hrs = 72ah per 24 hours. If your batteries are typical 210ah per pair (840 total) and you don't want to go below 50% charge, that's 420/72=5.8 days.

I do think it would better to run it on the 12 volt side because you skip the roughly 10%+ loss of efficiency through the inverter. The fridge changes the ac to DC anyway. Don't know the differing efficiencies inside the fridge of converting the 12V to whatever it uses internally vs the 120VAC to whatever it uses internally.

Ken

I have a Norcold fridge in my galley and run it on 12v only. My measured consumption was 86 Ah for a 24 hour period. But it will vary depending on ambient temp and how far you dial up the cold knob, as well as how often you open it to get stuff out.

Which Norcold?
Mine was a DE828, 2 doors, 2 compressors, each of whichruns only on AC 110v. The actual consumption on DC was >12 amps, as its internal inverter losses and the relative inefficiency of the AC compressors used a whole lot of power. I never measured the AC consumption when plugged into shore power.

If you have one that uses a Danfoss DC compressor, it should use only 3 amps, so running on DC will be much better than running on AC, though Norcold's dual voltage units, even newer ones, are likely as I have described above.

How much juice does your Inverter lose? Some lose 10%, so you may be in the same boat whether you run off the inverter or try Norcold's so-called "DC".

Which Norcold might be directed at OP, but mine is DE 0061. Two doors, 110 VAC or 12 VDC. Not Danfoss. Manual says start up 8A, running 5.9A.

The boat is mostly 230 VAC 50 Hz now (via inverter or shore power here is Oz), but I can still get 110 VAC via a transformer. But it is at 50 Hz, not 60 Hz. Ok for toaster etc but not good for anything with a motor.

Somebody already said it, depends on model, door openings and temperature.

I have a newer double door DE0061 Danfoss style. Norcold manual tells you not to run the fridge on 120v inverter. I would follow their recommendation and run on 12v or 120v generator/shore power only.

At Thermostat setting #5 it runs 50% of time 5 min. on 5 min. off if you want to keep ice cream frozen. Lower settings 3 or 4 will keep things already frozen, frozen over night and its run time is less. But don't be opening the door at that setting.

FWIW, I have discovered that if you leave the boat long term and don't open or close the refrigerator door, the power requirement drops almost in half. It also helps to drape a couple of towels over the unit to provide a little better insulation.

David

djmarchand said:

FWIW, I have discovered that if you leave the boat long term and don't open or close the refrigerator door, the power requirement drops almost in half. It also helps to drape a couple of towels over the unit to provide a little better insulation.

David

Click to expand...

An even greater effect if you have galley up is to cover the front windows to keep the sun off of the fridge. Galley down eliminates that problem.

are you worried about the bilge pumps at all ? I think I'd be inclined to take whatever I cared about in the fridge home with me, throw out the rest, and save all electricity for the bilge pump(s). You could be without power for a few weeks and unable to get to your boat for a while.

Toss in some dry ice into the freezer before you leave the boat.

Might give an extra day or two of no batt drain.

Benthic2 said:

are you worried about the bilge pumps at all ? I think I'd be inclined to take whatever I cared about in the fridge home with me, throw out the rest, and save all electricity for the bilge pump(s). You could be without power for a few weeks and unable to get to your boat for a while.

Click to expand...

Now that the storm is heading directly here that is the plan.

Thanks

Benthic2 said:

are you worried about the bilge pumps at all ? I think I'd be inclined to take whatever I cared about in the fridge home with me, throw out the rest, and save all electricity for the bilge pump(s). You could be without power for a few weeks and unable to get to your boat for a while.

Click to expand...

I agree. Take the food home and turn the refrigerator off. Simple and you don't have to try to guess how long it will run.

And fill your water tanks in case you need to move onto the boat after the storm. After cyclone Debbie parts of Airlie had no power or water supply for 10 days. Made living aboard the best option!