Norcold Runs Often

[Klompen]

Our SMB is about 10 months old. The build documentation says we have the old Norcold 2.6cf refrigerator, but we actually have the NR751BB Danfoss compressor unit.

It seems like this unit runs overly often. We were camping last weekend in cool, rainy conditions with the refrigerator set at 2 initially, then dropped down to 1. The compressor/fan would run for about a minute, then rest for only 7 minutes before the compressor/fan would run again. This seems like the unit is not running correctly. Can anyone provide some info on what is "normal" for them?

Our 200A battery didn't seem to be able to to support this unit for as long as we'd been lead to believe it should. We know that this uses more power than the older Norcold, but we want to figure out if the one we have is even behaving correctly. The fact that we got a less efficient unit is a different matter that we'll be bringing up with SMB.

 

[Twoxentrix]

I installed the exact same Norcold 3 moths ago - Admittedly I have not timed it, but have spent enough time in the Van to respond that what you are describing sounds about right. I keep mine set to "3", and have a 2yr old 225AH Lifeline (with 160wt roof Solar) - I'm not experiencing any unusual battery drain compared to the old Fridge...do you have Solar?

 

[Klompen]

We have a 100w GoalZero portable panel. Even with the rain and clouds, it was putting out 12.4+, but I don't know how many amps. The previous weekend the battery got down to 11.9 even with better sun. This time it was down to 12.2 by Saturday evening when we decided to run the engine to charge up. (So it was basically 26 hours to go from 12.9 to 12.2 and all we were running was the refrigerator and some lights.)

The fridge we were supposed to get is rated at 2.2A/h. The one we got is rated at 5.4A/h.

 

[Bellpilot]

We set ours to 3 or 4 while traveling during the day and when we stop we turn it down to 2. We also always bring a pound of frozen ground beef and stuff in the freezer which helps to keep fridge cool. About the 4th day we pull out the burger and it is usually still frozen. This plan seems to keep the the fridge from running a lot at night.

 

[Bbasso]

With refrigerators its best to keep them densely packed, the items inside will help to keep the temperature more even.
I've experienced this with my Engel mt45.
So my question is, how packed are you keeping it and how often are you opening it?

 

[Klompen]

Since these were both weekend outings and only about 40 minutes from home, I would not say that the unit was densely packed. The door shelf was full of beverages, the area under the shelf was packed, and the shelf was loosely packed with about 6 16oz Coke bottles. We had nothing in the freezer for either weekend.


Temperature maintained at about 39F both weekends. We don't get into the unit very often, especially this past weekend when it was cool so we made lots of coffee and didn't drink much coke.

 

[Grampswrx]

Make sure you pack the freezer with something even if you aren’t going to eat it. Use ice packs if you prefer. That will really cut down on the runtime.


Sent from my iPhone using Tapatalk

 

[Bbasso]

Good point I forgot to mention.
I use a bunch of these (5) all the time just to help maintain the temps better.

Also ambient temps play a role too. I have the transit bag (insulated protected covering) and I also built the cabinet with its own insulation. In hopes of saving electric and wear and tear on the unit.

 

[dosmena]

My Norcold started surging a few months ago. I think it was because I let the batteries go down to low and low current messed up the motor. Replaced it with an Isotherm. It takes up less space but has more volume inside. I don't even hear it running.

 

[Klompen]

My Norcold started surging a few months ago. I think it was because I let the batteries go down to low and low current messed up the motor. Replaced it with an Isotherm. It takes up less space but has more volume inside. I don't even hear it running.

What do you mean by "surging"? What model Norcold did you have and what model Isotherm did you replace it with?

 

[dosmena]

It was the 3.6 cubic foot Norcold. I think the model 41. It would power up for a two to three seconds then shut down. It cycled constantly. I replaced it with Isotherm Cruise 130.

 

[LenS]

Klompen - At the start of your trip did you pack it cold (40F) or were the contents closer to room temp.??


Really it looks like your refrig is performing as designed.


The spc for a NC751BB is 3.6a at "12" volts. 3.6a x 24hrs means a 86 a-h used per day. Your 200a battery can supply 100a of usable amps (50% of rating). So you should expect at 72F ambient 100/86 = 1.16 days of use ...or 28 hours of use to drain your battery (id: 12.9v down to ~12.1 volts).


To get down to only a 2.2a draw like you referenced would require something like a Isotherm CR-130 that costs $1,300.


Another comment you made was bought the refrig compressor turning on for 1 minute and off for 7. The refrig on/off cycle should be say 10 minutes on say 20 minutes off or something like that. 1minute-7minute implies to me that the compressor is stalling (low battery voltage), overload protection shutting system off for 7 minutes to cool down from the stall and then the refrig trying to turn on again but failing. Again normal on/off cycle is much longer. My refrig (different brand) cycle is 3 minutes on then 10 minutes off.

 

[dosmena]

I kept the fridge on all the time. Plugged in at home. It was installed when I bought the van in 2005.

 

[Merton]

Norcold fan runs but not compressor

I have two Norcold refrigerators in my SMB, one an upright and one a top loader that I use as a freezer. My problem has been that at first the top loader fan would come on but each time it's compressor would try to kick in it would fail. At that time the other fridge worked perfectly. I solved this initial problem by directly connecting a dedicated wire from the top loader to the main house battery terminal. Now my top loader works perfectly and my upright which is wired to an outlet away from the battery is having the same problem: the fan runs constantly and each time the compressor tries to start it fails. My house battery is fully charged with 12.7-13 V. Is this a wiring problem? Should I run another dedicated wire from the upright diectly to the battery terminal? Should I look at upping my battery capacity (I have two golf cart batteries with 400 amps capacity)? The two fridges work perfectly when I am plugged in to external 30 amps sources at RV parks or when I am running the engine and alternator. Any electricians out there? I think the Norcold fridges are not the problem. It's the wiring or the battery source? I think!

 

[86Scotty]

I have had this problem. You simply need to run a direct wire from your battery/fuse block to each fridge and fuse them properly for the wire. I have done 10 gauge wire with a 20 amp fuse (I think, can verify if needed) on many fridges and gotten this problem to go away. Same as you, the problem never happens when on shore power or running the van.

Oh, BTW, if you have two golf cart batteries you have a 200 amp hour battery bank. The GC batteries are 200 amps apiece but only 6 volts, making one 12v 200 amp hour battery when used together. Still, should be plenty for a day or two of running both fridges if your batteries are strong.

:b5: