Norcold DC558 compressor fridge power consumption

[M_canada]

I did a bit of a test today to measure the power draw of my Norcold DC558 compressor fridge option. It was about 20C/68F this afternoon. I had the fridge set to ‘2’ which maintained a fridge temperature of about 3C/37F. The fridge cycled on for about 7 minutes and then off for about 10 minutes. Power draw appears to be about 60W while on. This works out to an average of about 25W per hour under these conditions. One other thing to note is that I have I added insulation on the sides of the fridge enclosure, but I don’t know how much that impacts these results.

[Mike Lewis]

Good. Thanks for the info. Please keep us posted with more data as you obtain it. I'd be interested in how much power draw you have when it is really hot outside.

[DougO]

Thanks, this is very helpful. I have a deposit on on E19 and am trying to decide between compressor and absorption fridge. I echo Mike’s desire for more data. Thanks.

[M_canada]

Originally Posted by Mike Lewis

Good. Thanks for the info. Please keep us posted with more data as you obtain it. I'd be interested in how much power draw you have when it is really hot outside.

Will do!

[BobG]

I have the Norcold DC558. The specifications say it consumes 1.6 amps at 24 volts. After adjusting for the efficiency of my DC 24-12 converter, mine runs at 2.5 amps at 26.43 volts. That is about 45% more amps than specified and I have no idea why. When running, it consumes about 65 watts according to the battery monitor.



The refrigeration circuit is oversized and dedicated. I don't remember the wire size.



I do not have a record of how many minutes in a day it is running. At some point I will probably record this information.

[Chamberman]

Have you bypassed the 12 to 24v converter and measured the amperage running on 12V lately? If not, I would do this just to make sure something isn't going on with the converter.

[BobG]

Chamberman, that is a good idea. The converter is a Victron Orion 24 to 12 volt that is specified to be 92% efficient. I could bypass the converter and run the refrigerator at 24 volts to see what happens.


The electrical monitoring equipment report the refrigerator is using 66 watts when it is on.

[Chamberman]

Those efficiency numbers are usually on a curve with the best efficiency being in a somewhat narrow window. You'll probably find that at the current you're operating at your efficiency is well into the 80's.

[BobG]

I wasn't aware of the efficiency curve when I was making decisions on the system design but I sure looked hard and long at the 92% efficiency.



This morning I looked for an efficiency curve for this converter and can't find one.



The converter efficiency would need to be 64% for the battery to be delivering 2.5 amps and the refrigerator using 1.6 amps. Is this possible? If so, I need to find a different converter.


I will do a bypass but it will be a while before I can do it.

[Chamberman]

No I don't see how efficiency could be that low unless you were using a really low amperage at which point the power the converter requires in operation starts to look large when compared to the output power. I would think you'll be somewhere in the mid to upper 80's unless there is a problem with the converter.
Another thing you could do if you have a handheld DMM is to use the internal current meter on it which is normally good for 10A. This would require putting the meter inline on the output wire to the fridge. This will also give you a comparison to the system current measurements you're getting now. Just more data if you want it.

[BobG]

Marc, Like you, I have a 2021 21NE with the Norcold DC558 refrigerator. The way the refrigerator and door are situated the drip pan under the freezer can't be removed because the door can't be opened far enough for the drip pan to clear it.

When I defrost, I have to remove the drip pan support from one side of the refrigerator and then turn the drip pan diagonally to remove it from the refrigerator. Needless to say, this dumps water from the drip pan. One solution is to just leave the refrigerator off and open until the water evaporates from the drip pan after defrosting. What do you do when defrosting? Maybe your refrigerator is installed differently than mine.

[bborzell]

Originally Posted by BobG

Marc, Like you, I have a 2021 21NE with the Norcold DC558 refrigerator. The way the refrigerator and door are situated the drip pan under the freezer can't be removed because the door can't be opened far enough for the drip pan to clear it.

When I defrost, I have to remove the drip pan support from one side of the refrigerator and then turn the drip pan diagonally to remove it from the refrigerator. Needless to say, this dumps water from the drip pan. One solution is to just leave the refrigerator off and open until the water evaporates from the drip pan after defrosting. What do you do when defrosting? Maybe your refrigerator is installed differently than mine.

Hmmm…

The drip pan come out easily on our 2022 21C.

[BobG]

The 21NE is different than the 21C. The door on my 21NE can't be opened far enough to remove the drip pan unless the door is changed from right swing to left swing which would make the refrigerator not as convenient to use.

[M_canada]

Originally Posted by BobG

Marc, Like you, I have a 2021 21NE with the Norcold DC558 refrigerator. The way the refrigerator and door are situated the drip pan under the freezer can't be removed because the door can't be opened far enough for the drip pan to clear it.

When I defrost, I have to remove the drip pan support from one side of the refrigerator and then turn the drip pan diagonally to remove it from the refrigerator. Needless to say, this dumps water from the drip pan. One solution is to just leave the refrigerator off and open until the water evaporates from the drip pan after defrosting. What do you do when defrosting? Maybe your refrigerator is installed differently than mine.

I’ll double check next time I’m at my trailer, but I don’t recall a problem. My trailer is configured as a convertible rear dinette, so I can probably open my door wide enough to get it out cleanly if I needed to. I just put a bunch of paper towel on the bottom of the fridge in case the tray overflows when defrosting with door open an inch. We don’t take long trips, so the fridge doesn’t ice up too much.

[M_canada]

Originally Posted by BobG

Marc, Like you, I have a 2021 21NE with the Norcold DC558 refrigerator. The way the refrigerator and door are situated the drip pan under the freezer can't be removed because the door can't be opened far enough for the drip pan to clear it.

When I defrost, I have to remove the drip pan support from one side of the refrigerator and then turn the drip pan diagonally to remove it from the refrigerator. Needless to say, this dumps water from the drip pan. One solution is to just leave the refrigerator off and open until the water evaporates from the drip pan after defrosting. What do you do when defrosting? Maybe your refrigerator is installed differently than mine.

I checked today and my fridge door opens wide enough into the dinette to allow the drip tray to be removed.

[chesaka]

Originally Posted by BobG

Marc, Like you, I have a 2021 21NE with the Norcold DC558 refrigerator. The way the refrigerator and door are situated the drip pan under the freezer can't be removed because the door can't be opened far enough for the drip pan to clear it.

When I defrost, I have to remove the drip pan support from one side of the refrigerator and then turn the drip pan diagonally to remove it from the refrigerator. Needless to say, this dumps water from the drip pan. One solution is to just leave the refrigerator off and open until the water evaporates from the drip pan after defrosting. What do you do when defrosting? Maybe your refrigerator is installed differently than mine.

I have the 21ne and yes, it's hard to remove the drip pan because the fridge door butts up against the bed. I know this after a large bag of frozen berries thawed and spilled juice everywhere. I was able to remove without breaking the tray but only barely.

[chesaka]

Maybe an odd question but here goes: Do you turn your compressor fridge off when inbetween trips or leave it on as you would your house fridge? I'm talking about 2-3 week periods between trips.

[BobG]

Between trips I turn the refrigerator off, empty it and clean it. My trips are a week or longer. Lately the trips are not much longer than a week so I have not been removing the drip pan. The problem I see is that the drip pan has a reservoir in the back that I can not clean unless the pan is removed. I don't want it to get stinky by not cleaning it so I will be removing it every so often.

I wish the door had been designed so the pan could be removed when the door is open only 90° or the pan support system was designed so the pan could be removed without removing screws.

[BobG]

Mary, I also have the bed instead of the dinette. Did you have to remove the drip pan support like I do or were you able to bend the pan enough to get it past the door without removing the support? If you did not remove the support, I need to figure out how you did it. I see you live in Chugiak. I used to live in Anchorage.

[BobG]

I pulled the Norcold DC558 to do some wiring and after 4 months in the desert last winter and a couple trips this summer, this is what the condenser and condenser fans look like. The condenser is easy enough to vacuum without pulling the refrigerator but not the fans. I am also adding a couple inches of insulation against the side wall of the trailer behind the refrigerator and a couple more layers of the thin flexible insulation to the ceiling. The ceiling probably doesn't need it because there is a solar panel over the area and the sun can't get to it but when the sun hits the wall, it does heat up quite a bit. Maybe the extra insulation isn't necessary if the fans keep the air around the refrigerator about the same as the interior of the trailer. I don't know.