n841 norcold not cooling

[ufalco]

To all,
I’m new to the forum so be easy on me. First of all please redirect me to the right forum if this is not where I should be.
I own a trailer home in a very remote area in ny state with no electric available. I use generator at night only. 20 year ago I bought a 452 model norcold. I build a cabinet with proper vents according to the instruction book. Last year I notice a loss of cooling in the fridge, I call the authorize norcold tech and after a 5 minute examination and $95 fee I was told the fridge is no longer good. I bought a new and bigger model n841. I love it the way is switching between ac and lp and my wife is finally happy that this one is bigger hahaha. i used it 3 time in cooler temp outside it was working great. The last time I was at my camp it was very hot and humid in the 85-89f and notice that at the highest setting the fridge part was only be able to get 42f and 15f on the freezer part after running for one than a day. I feel that should be better than that. My qustions:
1) Is this normal and if it
2) Can I install outside fan to help out. I notice on my wire diagram there is an option fan, or just hook it up to an outside battery source that I’m already using to run the electronic part of the fridge. And if so how many and where can I put them.
i have attached a few photo

[clyon51]

It would be somewhat normal in high temps if it wasn't getting enough cooling air. It's looks like you did a great job venting it though. In my RV I put a 4 12v cooling fan array (computer fans) at the roof vent sucking air out. I wired them to a 100/130 degree thermal switch mounted below the fans. My Dometic fridge always needed to be run at the #4 or #5 setting. Now it runs at #2 and is 32 in the fridge and -10 in the freezer and does this with 90 temps outside.

[ufalco]

clyon51,
Thank you so much for the quick response and comments on my venting. I put a lot of effort in. what kind of thermal switch and where can I get it. Also I was thinking of installing the fan:
1) Under the coil pushing air up the chimney
2) Or on top of the fins pushing air up to the chimney
3) or both
What you think about that. would this work.
and how much battery power would that consume

[clyon51]

Originally Posted by ufalco

clyon51,
Thank you so much for the quick response and comments on my venting. I put a lot of effort in. what kind of thermal switch and where can I get it. Also I was thinking of installing the fan:
1) Under the coil pushing air up the chimney
2) Or on top of the fins pushing air up to the chimney
3) or both
What you think about that. would this work.
and how much battery power would that consume

This is the switch I bought, except mine was 100/130

Thermostat Switch - Circuit On At 120°F and Off At 105°F - Large Flange - Amazon.com

This is the fan unit, rated at 0.37a draw for the 4 fans. Of course with the thermal switch that will be far from constant.

ASSEMBLY W/4 12VDC 80MM FANS AND GUARDS | AllElectronics.com

A lot of experimentation has been done on this forum regarding fan placement. The best setup it to put the fans as close to the roof as possible to suck the hot air out. Placing them in a low position pushing air up or just blowing on fins causes turbulance within the unit. Although better than nothing, it's far from most efficient. Hope this helps.

[ufalco]

Nice thanks you so much.

i found this from nordcold.i just don't know the close and open temp.
http://www.americanrvcompany.com/Norcold-618093-Refrigerator-Part-Thermostat-DC-Fan-Trailer-Camper-RV

I’m looking at the possibility to use the wiring from the unit to install the thermostat and fan. I’m not an expert but it’s listed in the diagram as option fan and temperature switch. I will have to make sure to connect those correctly
As far as installing the fan I was saying to put the fan(s) on top of the fins area but blowing away from the fins toward the top going out to the chimney. For me as you notice my installation I have no way to put fan close to the roof area.
Questions:
1)Is one fan enough
2)Is the installation I listed above ok and efficient
3)I’m thinking to put the fan inside my 6” pipe just before the cap blowing out would that work and be ok
If all of this is not adequate I’ll have to put everything apart and maybe install the fan set you suggest on top of the fins area blowing out hot air

[clyon51]

Originally Posted by ufalco

Nice thanks you so much.

i found this from nordcold.i just don't know the close and open temp.
http://www.americanrvcompany.com/Norcold-618093-Refrigerator-Part-Thermostat-DC-Fan-Trailer-Camper-RV

I’m looking at the possibility to use the wiring from the unit to install the thermostat and fan. I’m not an expert but it’s listed in the diagram as option fan and temperature switch. I will have to make sure to connect those correctly
As far as installing the fan I was saying to put the fan(s) on top of the fins area but blowing away from the fins toward the top going out to the chimney. For me as you notice my installation I have no way to put fan close to the roof area.
Questions:
1)Is one fan enough
2)Is the installation I listed above ok and efficient
3)I’m thinking to put the fan inside my 6” pipe just before the cap blowing out would that work and be ok
If all of this is not adequate I’ll have to put everything apart and maybe install the fan set you suggest on top of the fins area blowing out hot air

I would only use a thermal switch of a known temperature range, approx 100/130. Otherwise, it may or may not come on, or shut off.

Unless you know what you are doing with the optional switch and fan setup, I would just wire it to the main 12v power connection the fridge uses. Use 16ga wire, wire in a 3amp fuse on the POS side, run that to the thermal switch. Then out of the switch to the POS on fan. Run NEG from fan back to NEG at power source.

One fan would probably be OK with the proper thermal switch and if it is within the narrowest part of the chimney. The object is to have as little room around the outside of the fan(s) as possible. In other words, fill the hole with fan. Looking again at your pictures, that 4 fan array looks like it would fit nicely into that triangle duct you have. I still think you did a superb job with the venting, so it's still possible you may have an adjustment problem with your Norcold.

[ufalco]

Yeah I agree with you to use your suggested thermal switch and the 4 fans install right under the metal piece. That metal piece I had made its 5 ½ in wide by 24 in long and convert to a 6” round. The fans would fit nicely there and it’s placed right above the fridge and the fins parts.
What did u mean by “possible you may have an adjustment problem with your Norcold.”
Where would the thermal switch be located?
would a thermal switch of 100/85 be to low?

[clyon51]

Originally Posted by ufalco

What did u mean by “possible you may have an adjustment problem with your Norcold.”
Where would the thermal switch be located?
would a thermal switch of 100/85 be to low?

I don't know anything specific about Norcolds. I've just heard it has an adjustable "thermister" which I believe just adjusts temperature differential between fridge and freezer. For just $25, I would install the fans which will improve overall operation anyway. You of course can look into the thermister anytime.

You want a thermal switch that will shut off at a temperature that is above the outside temperature. So if you had one at 85, and it was 85+ all day, it would run continuously. Not good in a battery only situation and isn't necessary anyway.

The ON temp isn't as critical. 110 to 130 is good. Once the fans kick on, they only run a minute or so before they will shut off anyway, if the OFF temp isn't too low.

I would strongly suggest you either move the fans higher in that duct to close the gap around them or, if you mount them in that 24" long space to build a baffle that they will fit into. This assures all air is pushed out the chimney rather than some being recirculated inside the duct. This also reduces run time of the fans saving battery. This may even make it much easier to mount them.

Mount the thermal switch an inch or so below the fans. You want it high where the hottest air is.

[whem2fish]

As far as nor old having a adjustable one if I remember right move it up on the fin for colder now a aftermarket is out for the domestic last I read last month they are working on a nor old but not ready yet I run 4 fans at the top and one in the fridge

[clyon51]

I also run one in the fridge blowing on the fins. Keeps ice and frost off them and keeps fridge at a more even temp.

[Ed-Sommers]

In my opinion, one fan (or more) blowing ON the the coils is the most efficient way to cool the coils. The small 12 volt computer type muffin fans are not really designed to pull air, but to push it, thus providing a greater air flow.

And yes, by pushing that little clip on one of the fins inside the reefer up further, you should get lower temps, and temps will be more consistent with a loaded box rather than an empty one.


Ed
USN Ret.

[Muddypaws]

There is an adjustable for NorCold. Product Listings for Snip The Tip. Not sure about your model. I worked with the engineer/owner to modify his Dometic parts to work on Norcold but all my calculations & testing were done on a 1200 series.

If there isn't one for your model try the 'Muddypaws Mod'. Put a single layer of foam insulation (from a coffee cup) between the fin and the thermistor. Assuming that you have a thermistor that actually clips onto the fin. Some Norcolds use a different type.

BTW: running at a higher number may actually be counter productive. At least I know it is with the 1200 series. They work best at a setting no higher than 4.

Mine used to be too warm too. Now it keeps things (especially beverages) very cold.

Good luck.
Muddypaws

[ufalco]

Thanks to all,
I see I have some work to do. Meanwhile I’ll gather all that I need for the next trip up to my trailer home. I guess I’ll try the easier way first that works for me. I’ll report back of the outcome. Thanks you all once again. It’s been really Great help.

[ufalco]

so if i decide to go with one fan blowing up in the coil area where would i place the thermal switch.