Question on Norcold Refrigerator

P

pat.jack

New member
Hi Folks,
Looking for some help on a Norcold mdl NR740 refrigerator. The refrig. works on AC power, and when I pull the plug it switches to DC and seems to work fine. If I try to power the refrig on DC alone, it will not operate at all. The battery is fully charged-and well above the minimum cut in voltage mentioned in the owners manual. I made 5 phone calls this morning trying to get an answer if this is correct-or should the refrig operate on DC alone and I can't get an answer. Norcold (Thetford mfg) won't provide technical assistance unless you're a dealer. Defender could not provide tech assistance, and I tried the 'local service' centers Norcold recommended and they did not know the answer to this. I am faced with pulling the refrig back out of the boat and driving it to a local repair center so they can call technical assistance at Norcold!! I have read over the owners manual a half a dozen times and I can't seem to get an answer that addresses this situation. I would like to at least get an answer while the unit is under warranty.

Do any of you have experience with the operation of this type of refrigerator? Sorry for going into so much detail, but it turns out I need to take the boat in to a Honda dealer this morning to get the engine serviced, so I am trying to get this answered before I trailer the boat the 40 miles to the Honda dealer-so I can decide to pull the refrig before I drive it.
Thanks,
Jack Howell
 
pat.jack":1g9y7b85 said:
Hi Folks,
Looking for some help on a Norcold mdl NR740 refrigerator. The refrig. works on AC power, and when I pull the plug it switches to DC and seems to work fine. If I try to power the refrig on DC alone, it will not operate at all. The battery is fully charged-and well above the minimum cut in voltage mentioned in the owners manual. I made 5 phone calls this morning trying to get an answer if this is correct-or should the refrig operate on DC alone and I can't get an answer. Norcold (Thetford mfg) won't provide technical assistance unless you're a dealer. Defender could not provide tech assistance, and I tried the 'local service' centers Norcold recommended and they did not know the answer to this. I am faced with pulling the refrig back out of the boat and driving it to a local repair center so they can call technical assistance at Norcold!! I have read over the owners manual a half a dozen times and I can't seem to get an answer that addresses this situation. I would like to at least get an answer while the unit is under warranty.

Do any of you have experience with the operation of this type of refrigerator? Sorry for going into so much detail, but it turns out I need to take the boat in to a Honda dealer this morning to get the engine serviced, so I am trying to get this answered before I trailer the boat the 40 miles to the Honda dealer-so I can decide to pull the refrig before I drive it.
Thanks,
Jack Howell
Click to expand...
When you say you "pull the plug" do you mean the plug from the fridge to the 120V outlet or the plug to the shore power? If the former, I assume you have a battery charger wired in and that it is supplying the fridge with sufficient DC current to make it work. If so, I'd check the the DC voltage at the fridge prior to and after disconnecting the shore power. I bet you see a drop and it may be that the connections to the battery are bad or that the battery itself is bad.
 
Hi Roger,

Thanks for the response. Yes, I did add a battery charger. However, that was not involved in the issue I described. I ran an AC extension cord to my house to power the refrig. I pulled this ac cord and let the refrig run on the boat battery-no charger involved providing a possible increased (DC) voltage source. The refrig ran fine on the boat battery alone. So, I am going by the assumption the battery is fine. The rest of the issue is as described in my previous note.

I'm most disappointed that I cannot seem to get an answer to what I think is a relatively simple question-will the refrig run on DC alone?? I can live with it the way it is--but I want to make sure there is no defect with a brand new $750 1 and 1/2 cu ft refrig. Seems like a reasonable request to me.
Regards,
Jack
 
pat.jack":15r5qifo said:
Hi Folks,
Looking for some help on a Norcold mdl NR740 refrigerator. The refrig. works on AC power, and when I pull the plug it switches to DC and seems to work fine. If I try to power the refrig on DC alone, it will not operate at all. The battery is fully charged-and well above the minimum cut in voltage mentioned in the owners manual. I made 5 phone calls this morning trying to get an answer if this is correct-or should the refrig operate on DC alone and I can't get an answer. Norcold (Thetford mfg) won't provide technical assistance unless you're a dealer. Defender could not provide tech assistance, and I tried the 'local service' centers Norcold recommended and they did not know the answer to this. I am faced with pulling the refrig back out of the boat and driving it to a local repair center so they can call technical assistance at Norcold!! I have read over the owners manual a half a dozen times and I can't seem to get an answer that addresses this situation. I would like to at least get an answer while the unit is under warranty.

Do any of you have experience with the operation of this type of refrigerator? Sorry for going into so much detail, but it turns out I need to take the boat in to a Honda dealer this morning to get the engine serviced, so I am trying to get this answered before I trailer the boat the 40 miles to the Honda dealer-so I can decide to pull the refrig before I drive it.
Thanks,
Jack Howell
Click to expand...

Yes, when you turn off the 110 volt, disconnect the shore power, un plug the unit from 110 volt 15 amp plug, it should switch over to the DC power.

I am confused because you say it does work on DC when you un plug the cored, but will not run on DC in the boat?. Yet you say it does not start on DC power? Have you varified that you have 12 volts to the power leads in the boat? That a breaker is not thrown or a switch issue?

If it was an older unit or used, and would not run on DC then I would say bad circuit board.
 
pat.jack":17vyzgvi said:
Hi Roger,

Thanks for the response. Yes, I did add a battery charger. However, that was not involved in the issue I described. I ran an AC extension cord to my house to power the refrig. I pulled this ac cord and let the refrig run on the boat battery-no charger involved providing a possible increased (DC) voltage source. The refrig ran fine on the boat battery alone. So, I am going by the assumption the battery is fine. The rest of the issue is as described in my previous note.

I'm most disappointed that I cannot seem to get an answer to what I think is a relatively simple question-will the refrig run on DC alone?? I can live with it the way it is--but I want to make sure there is no defect with a brand new $750 1 and 1/2 cu ft refrig. Seems like a reasonable request to me.
Regards,
Jack
Click to expand...
Jack,

I too am confused by your description in which you say it ran fine on the boat battery alone but won't run on DC alone. Do you mean that it switches over from AC to DC fine and runs on DC just fine BUT when turned off and then back on while only connected to DC it won't run?
 
pat.jack":30e8m6gz said:
Roger,
Correct. That's what it is doing.
Regards,
Jack
Click to expand...
Does the blue LED light come on when only connected to the battery and the unit is turned on and the door is opened? If not, it sounds like the electronics/relay (not sure which) that are responsible for switching over to DC are defective. If the LED light comes on, then clearly some DC power is getting to the unit but perhaps not enough current to run it effectively. Still, it's sounding like a defective unit to me.
 
Bob,

I re-read my post and should have added-'when I pulled the ac power cord'--not simply that I pulled the cord. Hopefully that addresses the confusion.

It probably does not help that I have to keep my head down to find the keys to type these posts!!
Thanks for your interest.
Jack
 
Roger,
Regarding your question-on DC only there is no LED blue light or any evidence of cooling operation. It simply appears dead. When it operates properly-there is the LED blue light-when the door is open and it does seem to operate fine. I'm guessing there is an electronic switching problem. I just have not had success getting an answer from Norcold. Defender so far has said it is a warranty issue between me and Norcold-and Norcold does not seem interested in answering my question directly and the owners manual does not address this operation(DC only).
Regards,
Jack
 
pat.jack":3uf4m7bc said:
Roger,
Regarding your question-on DC only there is no LED blue light or any evidence of cooling operation. It simply appears dead. When it operates properly-there is the LED blue light-when the door is open and it does seem to operate fine. I'm guessing there is an electronic switching problem. I just have not had success getting an answer from Norcold. Defender so far has said it is a warranty issue between me and Norcold-and Norcold does not seem interested in answering my question directly and the owners manual does not address this operation(DC only).
Regards,
Jack
Click to expand...
Sounds like a defective circuit board to me.
 
We have a Dometic tundra fridge on our cc-23 It came with the boat .It used to work like this, plug in shore power and it would sense that it was over 17 volts and it would switch over to AC power . When you would shut off shore power it would go to 12volt DC power . However now it just works on DC power . I cannot get it to work on 115 AC (shore) power . I was told by Tundra rep that the circuit board relay was fried for about $300 I could fix it .The way I can tell if it's on is a light comes on when the door is opened . No thanks I just put on shore power and battery charger and then 12 volts DC power will keep it cold .
I've thought about getting a portable fridge /freezer model and taking out the Tundra model . We just don't use the fridge we usually use a cooler .I like the idea of making ice and freezing your meals .The Tundra takes down batteries way to fast .If you are having problems right from the get go something is amiss.
 
Hi C-Brats,
I figured I'd give you an update on my Norcold/DC operation problem. I did pull the refrigerator back out of the boat and drove it to a Local RV dealer across the county 2 days ago. I took the unit to 'Johnson RV Country' for those interested. I called the guy at the RV dealer today and he confirmed the problem as I described-which is always a good thing. He told me he spoke with Norcold-and they say it sounds like a defective circuit board, which makes sense. I just emailed the RV dealer my Defender receipt so he can supply proof of purchase to Norcold. I am not sure when they will finally repair the unit, but hopefully a repair is in process. Needless to say it is disappointing that Norcold would not deal directly with me-and Defender simply stepped away from the problem. Luckily I had a RV dealer that was willing to help.

In any event-my boat is at a Honda Marine dealer repairing my 90 hp engine. So, if I'm lucky the refrig repair and engine repair may come together at the same time and I can re-install the refrig and finally put the boat in the water this year!!

When I finally get proficient at posting pictures I'll share the work we completed this summer.
Jack Howell
 
Fridge problem: it (Norcold AC/DC NR740/751?) doesn't work.
Up north, for 2 years in the cold, it worked fine the little it was used.
Now down south where it's (supposed to be) warm, the cooling
device does not work; it won't turn on.

There is power to it. Don't know where to find/check a fuse and
that's not shown in the manual.

How to check for a shot condenser, blown fuse or other malfunction
short of calling in a local service tech by van and expect to get robbed.

Are Maytag repair men still around? They're usually not busy, right?

Arg.
 
Foggy, hope you get an answer before the steaks thaw. Sorry, I have been cruising with out a fridge or cooler for the last several years, (just using the hold under and in front of the front passenger seat. Works well where the water temp is 45 degrees. Guess if I think about going south, I may need to come up with a cooler solution too.

Wish you the best. Stay safe.

Harvey
SleepyC :moon

IMG_2044_sized_1.thumb.jpg
 
Journey On has a Norcold refrig. It's the one the factory put in. I've pulled it out to insulate it for sound and thus had a peek at the electrical supply.

If you're asking if the Norcold will run on AC and DC, here's the answer. Simply put, if it works on AC and the external DC is wired in and turned on, it's gotta work on DC. The reason is that the AC feeds a DC converter which then powers the refrig. So, if it's running when the AC input is ON, it's really being fed DC internally.

If it doesn't work on DC only when you turn it off and then on, another question entirely, check that the boat DC is ON to the refrig. If that's ON the break in the DC line must be internal, somewhere at the output of the AC/DC converter. I didn't see an internal fuse. In either case, AC or DC, the switch operates on DC power, so I assume one gets the same result with either AC or DC. BTW, have you checked the battery voltage when you have it feeding the refrig? If it's too low the refrig might not start. On AC, it's always at the converter level.

Boris
 
Foggy,
I replaced the factory Nova-Cool with a sim Norcold 3.0 cf unit.
If there is power from AC or DC, and the temp control knob is not OFF (full counter-clockwise HARD click) I get a blue LED on when the door is opened. Turn the temp knob to 3 to be sure it's not OFF. (Mine gets very sticky).
Here's the 741 manual. (After you print it, you may notice that the French portion smells like garlic-flavored cigarette smoke).

http://www.defender.com/pdf/NORCOLD_OWNERS.pdf

Pull the fridge, it's only 4 screws.
As Boris noted, it's ultimately a DC fridge, so to rule out other issues plan on connecting a known good battery or 12v source > 12.5v directly to the 12v input at the back of the fridge after you cut that wire as needed.
Mine had an ATO 12v fuse back there, and also an un-labelled fridge 12v 10A ATO fuse in the helm bus block under the helm. Who knows what else lurks in the path of your fridge getting power, thus the need to connect it directly to a known good 12v source and back-trace from there.
If this doesn't solve it, you could trash it, which is your most cost-effective option as you're way out of warranty. When these get a micro-leak hole, bad circuit board etc service calls add up fast. It has a 2-year warranty because that's how long it's Maker figured most would last.
Hope it's something simple like a bad connection. It often is.
PS my only complaint with this unit is that the bottom non-hinge side may not seal on closing, or may crack open in rough seas, leading to massive air leak/ frosting. Same issue on brand new units at local Westmarine!
PPS: I replaced all ATO fuses with Ancor Easy ID fuses, which light up when blown. It's hard to ID blown fuses already, these make it easy and obvious, though not cheap, but way cheaper here than at Westmarine.

https://www.amazon.com/Blue-Sea-Systems ... asyid+fuse

Happy Boating!
John
 
Foggy,
Your unit should have a Danfoss compressor. It does run on 12 volts DC, with a 120 AC converter. (The older Norcold's used a Swing motor running on 27 volts Ac--yours does not).

First you need to check with your digital volt meter what the 12 V DC voltage is at the refrigerator. It should be at least 12.6 volts. Also confirm that the 120 V AC circuit is intact.

It is not unusual to have lower DC voltage because of a number of factors: Corrosion is first. Secondary is the wiring size may not be adequate. (Good to at least double the wiring size to the main console of the C Dory--as well as put in a larger fuse block for the circuits. More appliances often are hooked up than the original wiring can handle, and a voltage drop occurs).

It is likely that there is a dedicated fuse to the 12volt DC refrigeration circuit of your boat. I am not familiar with the Venture 26's panel, but most likely it is similar to the C Dory 25/Tom Cat. There can be both breakers and fuses. Hopefully someone labeled all of the wiring behind the console--(Another good thing to do when when buying a boat). Trace out the refrigeration wiring.

Look for corrosion on the ground (negative)--all of the way back to the battery, check tightness of all terminals.

There is a good video on checking the controller and compressor for the Danfoss BD 35

I am not sure if this testing is within your capability. If not, then the refrigeration guy cometh.

Penguin Refrigeration has another video on the basic circuits also.

Other areas to look at include the thermostat, or thermister circuit--at least run it back and forth to be sure that the contacts are working properly--not something you can take apart.

If the compressor is running, the fan is running properly, but the unit is not cooling, it probably is low in refrigerant. Unfortunately these "cheap" units are not made to be recharged. A good tech can braze or silver solder in a Schrader valve and recharge the unit. They require very small amounts of refrigerants, and not something you should do, even if a Schrader valve was present.

Frankly most techs just say, "replace the entire unit". I don't know if you are near Pensacola. I don't think our marine refrigeration tech recharges the units. There is another guy who might. (If that is the problem)

Also RV techs may or may not have the capability of working on these compressor driven units, since the majority of the RV Norcold Refrigerators are adsorption, not compressor driven.

Let us know what you find on the electrical side first. Good luck!
 
Jack,

All of these marine refrigerators are 12 VDC based. The AC/DC models have an innverter which converts the 120 AC form the power outlet to 12 VDC used by the refrigerator. You do not need an AC/DC inverter if you have a battery charger on board (it performs the same function).

As to your start up issue, I would start by checking the input voltage to the refer. On DC start up and if measured input is 12+volts the unit should start (given a fully charged battery). Remember that refer. start up electrical demands are much higher than running demands.

Hope this helps.
 
Guyz, thanks. I've been using an iced cooler also andthe dead
fridge as storage. I can live this way if need be. If it comes to it,
I may yank the thing out and fill the space with my rubber duckies.

I'm more a meat and potatoes guy than an electrician.
Never could fuss with invisible stuff but your comments are
helpful. The manual says "AC/DC" so I'm not asking about that.
The panel has "refrigerator" and I know enough that it has to be 'on'
along with the main distribution panel turned to "House bank" for the
fridge to work. I have a smart battery charger (ProNautic 1220P) and
a volt meter with 2 pointy ended colored wires.

Now, the house battery is below 50% (about 12.09v) after sitting here
since last October w/o use/charge. As I recall, the thing didn't work
most of last summer in Michigan with the battery 12.6v or better so I'm
guessing it's not a battery state of charge issue.

A marine techie looked at it briefly yesterday and reported "There is
power to the refrigerator" equating to about $20/word. I found a
company in Naples who say they do "Marine HVAC, Electrical and
Refrigeration" and are on the way south to 'fix it'. I'm prepping to
get hit with more $ zeros.

This may be the Universe telling me to sell the boat, which is no longer
"cool" for a couple reasons including the above. Maybe not. With this
in mind, I may defer a decision to replace or yank it out until there is a
sale pending. Maybe Marc in Eastpoint can pop a new one in if a buyer
wants it.

Aye.
 
The manual says "AC/DC" so I'm not asking about that.
Click to expand...

The question is has it run on AC?, since it should be plugged into an outlet behind the refrigerator? Is the AC breaker on, as well as the DC breaker. In most of the C Dory's the AC breaker will be on the panel under the table seat. The DC switch and breaker is on the console. But apparently the marine tech was able to get behind the refrigerator and check voltage--just having 12 volts there may not be enough under load. If the batteries sit for time with significant discharge, there will be damage to the battery. Having 12 volts at rest, with no load, does not necessarily mean that there is high enough voltage to operate the refrigerator when the compressor/fan are running. (not sure where the cut off voltage is for that refer, but probably in the 11.5 range).

The video I linked to dose show how to test the compressor, fan and get ideas if the circuit boards are working correctly. The refrigeration tech should do these tests. Having some idea how that is done, gives you at least confidence that the refrigeration tech knows what he is doing. (Some are just plug and play--especially with the small Norcold's)

Now, the house battery is below 50% (about 12.09v) after sitting here
since last October w/o use/charge
Click to expand...

'there is an adage, "never let your battery get below 12.2 volts for any period of time. Is the battery below 12.09 volts currently (you used the word "now", which is a little confusing)?

volt meter with 2 pointy ended colored wires
Click to expand...
Foggy, the red probe is positive and the block probe is negative. However, with this amount of knowledge, I would suggest that you stay away from use of this, since tangling with the wrong wires, could be fatal. Too late now, but I really do suggest that every boat owner know how to do at least simple diagnostic electrical work. A book like the "12 volt Bible for Boats". Which costs about #12...is a very good investment. I write this for those who are reading and don't have any electrical knowledge, not to chastise foggy.

I wish you luck in repair/replacement of the refrigerator. Please let us know what the refrigeration tech says/ does.

You had mentioned selling the boat once before. Hopefully this refrigerator problem is not the catalyst to cause you to sell. Many of us enjoy our boats with simple ice chests.
 
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