refrigeration

About 9 years ago I replaced a Nor cold refrigerator on a new boat to us with a new 0041 Nor cold. In 9 years I bet there is less than 10 hours of use on it. The reason, It kept shutting down when in DC mode. When in AC mode it seems to work ok. We do not do a lot of slips in our travels there fore not using shore power and recently I removed the Genset. I have decided to tackle this problem and find out what is going on with this old by age but new by use refrigerator. (Tired of buying ice). Here is what I have observed and discovered. The literature says the unit must be run for 8 hours before filling. Question , AC or DC. When on AC it does cool, not sure how cold yet. Also have not run 8 hours before filling. When batteries are charged to 12.8 volts measures by Vitron Energy Smart Shunt after running a portable honda generator I hear the unit running on DC. On DC the unit does not seem to get very cold. Also at 11.9 Volts I think the unit shuts off. The literature says it shuts down at 10.4 volts. I know 10.4 volts and that battery is dead. I know time running on DC is directly related to available amp hours. I only have 230 and at 50% 115. I am installing solar and I can double the amp hours. Still I do not want to do all of this and find the Norcold is also a problem. My brother has the available amp hours I could go to and solar with a refrigerator seperate compressor and condenser. He has no run problems and has to turn the unit down, things freeze. No 8 hour pre run time. Norcold uses danfoss and I believe it has an inverter built in so it runs on AC all of the time. Any thoughts, suggestion or comments?
Ken

Is it a compressor fridge or an absorption fridge?

It should not matter whether it is on A/C or DC for the cool down period. They just don’t want you to load up a bunch of food when the refer isn’t cool. They don’t do well that way.

My previous boat had the original box with upgraded 12v compressor. I liked that as converting 12v DC to 120v AC wastes some battery duration.
My current has a 12v DC compressor which runs off 12V Dc battery directly or 120V AC which is transformed to 12V DC for the compressor.

Worked great until it stopped auto switching. Have determined the auto transfer switch is fused to 120V circuit only, but runs on transformed 12v DC.
Soon as I find time I will be hot wiring to 12V DC use only.
Fridge has been running 24/7 since I bought the boat so not aware of 8 hour operation before loading.

Just a wild guess without being there to check things; you probably have excessive voltage drop between an undersized battery bank and the compressor.

Nevercold (Norcold) refrigerators have poor insulation and the one you have may be powered by a piston compressor as opposed to a rotary.

I'd had enough of mine and went down this road. Half the price, twice the efficiency, 50% larger, and FROST FREE, what's not to like.


Ted

The voltage drop issue needs to be addressed. The plus’s side is supposed to be wired directly to the battery. It presently goes through a breaker switch and a couple busses. I do not measure a voltage drop but I think I will run a temporary jumper directly fro the battery and see what happens.
Ken

If you have adequate size wiring to the refer it shouldn’t matter if it is directly wired or not. Mine isn’t wired directly to the battery because I want to be able to control it through the breakers. However I always oversize the wiring so I get excellent voltage to whatever device I am powering.

I have a DE0061 Norcold and a DE0041. I also have noticed the same on both fridges, always work fine on AC but only sometimes on DC. REALLY sometimes and very random, not reliable temps. I was determined to figure this out and believe I have. I think it’s all related to the “feature” these have to prevent you from running down your batteries. Buried in some literature I found the spec that the fridge would shut off if the voltage EVER went below 11.0 and would not restart unless the voltage went above 12.3. Well, between normal voltage drops to the fridge and using a microwave on board, this can and did happen! After the fridge got into this mode, I could hear it start up and as the compressor ramped up in speed, it would shut down, wait 30 seconds or so, then repeat the process, continuously for maybe hours and hours, with very little cooling generated.

My fix, now proven on both fridges over 3 months of continuous use on DC only - I installed a Victron, Orion 12 to 24 Volt 10amp DC-DC converter on the DC input on each fridge. These converters will take a range of 8-17v input and convert it to a steady output of 24v adjustable in a range of 20-30v. I set mine for an output of 25v. (These fridges accept 12v or 24v)

Without any other changes whatsoever, both of my fridges have been working flawlessly continuously for the last 3 months on DC only.

Ken

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Kchance
I have felt my problem was the same. I never thought of regulating the input voltage. I read the drop out voltage was 10.4 volts and yes it does not turn back on till 12 something. I will try the dc to dc converter.

I had my Norcold 0061 stop working on DC. I ran it on AC for a year or so before it stopped working completely. I then replaced the control module and it's been working perfectly on DC and AC ever since. Don't rule out a bad controller.

As an aside, I'm not convinced that there is a big power consumption difference between AC and DC source. I usually leave my inverter on 24/7 and don't see any big difference in daily power use when switching the fridge between AC and DC.

In all my testing, I never did a test to compare Norcold’s DC power consumption vs AC but I agree, I think they are pretty close. However in my case, my inverter (Magnasine 2812) uses 3.5A continuously just to be turned on. (84 amp hours per day) That is more than one of my fridge’s average. Now that my Norcolds are running very well on DC alone, it’s a no brainer for me to turn off the inverter and use DC whenever possible. It makes a big difference in my daily power budget and allows my 700watts of solar to easily power 2 refrigerators and all of our normal house loads with no need to run the generator.

Ken

Kchance,
Happy to hear no generator. Recently I removed a 5KW Westerbeke generator. The engine was great but the back end went bad. I bought a rebuilt from Westerbeke. To install I had to remove the complete unit engine and generator. After removing the complete unit with sound box I loved the available space in the engine room. Sooo now I am trying to configure everything with an increased house bank and replace a sterling charger with a ventron charger / inverted. I will keep on board a Honda 2200 generator just in case. It is encouraging that you are not needing a generator.
Ken

I can usually get by with no generator and have been doing it, but you have to be very aware of how much power you’re using and have enough solar to cover it and account for rainy days too. For example, running 2 fridges was ok, but the additional 82ah a day used by my inverter was pushing it especially on rainy days. One of these days I have a plan to up my power from 700w to 1000. That will really help too. But having a backup source like the Honda will help too.
Ken

Hello K: check that the fridge DC ground wire is connected to your DC system. My DC ground wire was connected to the AC ground wire side in error. Makes a difference.

Ventilation was my problem

I was very close to ripping out my DE0061 N'rcold because it would randomly warm up and let food spoil. I had similar questions about AC vs DC operation and the whole low voltage cutout issue. In the end, I believe those turned out to be coincidences. My fan had accumulated gunk and dust and would periodically fail to start with the compressor. That was problem 1 and a new $12 fan fixed that.

Problem 2a was a failing thermostat that would fail to start the compressor at seemingly random times. Rather than replace it with a new and very expensive unit from N'rcold, I replaced it with a $12 digital thermostat from Amazon that held the internal temperature to a much tighter set point.

Problem 2b was that the new digital thermostat also failed. That made me think there was a problem 3, but unlikely as it felt, the nearly new digital thermostat also periodically failed to close the contact that started the compressor. In hindsight I now see that it is very believable for a $12 thermostat from China to fail. I now keep two in backup.

Works like a charm now. Ice and ice cream is rock hard. Beer and pop is ice cold. Life is good. Until the next thing fails, of course.

Yebogogo said:

Ventilation was my problem

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Ventilation is always where I start in troubleshooting a refer problem.

I am suspecting your 12 v wiring is not heavy enough. Check the Blue Sea chart, but the load on startup can be considerable and makes the fridge think the battery is too low.

I always calculate what size wire is needed based on current and distance then go at least one size larger. It is a small one time cost but it pays off every time you use the device in that you get excellent voltage to the device.

Comodave said:

I always calculate what size wire is needed based on current and distance then go at least one size larger. It is a small one time cost but it pays off every time you use the device in that you get excellent voltage to the device.

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This is my practice as well. There is simply no significant change in cost until you get past 6 gauge wire.

My small Norcold is wired with a #10 wire. Even then, when someone flushes the toilet (electric), the fridge shuts off.

When a compressor starts it will pull multiple times more amps than normal running. This can momentarily cause a voltage drop especially if you have a small battery bank. So your refrigerator ends up shutting itself off from low voltage.

My fridge is wired directly to the battery using one of these. BLUE SEA 5023 ST BLADE BATTERY TERMINAL MOUNT FUSE BLOCK
Most fridge companies will tell you not to wire it through the circuit breaker panel to minimize voltage drop. Wiring directly to the battery also prevents accidental shut off. As mentioned the gauge of the wire cannot be too heavy. Heavier is better.

If you dig up the manual, the low voltage cutoff for the Danfoss / Secop controllers can be adjusted. If it's set higher than the lowest setting, the fridge may be cutting off due to low voltage, but still be at a voltage where it would be capable of running.

Kchance. Used your solution and frig has been working great ever since.

kpinnn said:

Kchance. Used your solution and frig has been working great ever since.

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That’s great. I can also report that my 2 Norcold fridges have been running continuously with the Victron DC to DC converters since April with no issues whatsoever and holding temps. (I monitor with in fridge thermometers) when the temps start to not quite get down to where they usually do, a quick defrost of the fridge compartment immediately restores them to nice low temps.

Ken