Fridge cooling fans keep burning out

[cimplexsound]

[ATTACH]
I installed a computer cooling fan on the outside of my RV fridge back in July because it was struggling to keep my food cold. It was wired in through the 12 volt accessory port on the back of the fridge to help keep the condenser cool. Found a more level spot for the RV where the fridge works much better now. However my first fan burned out after a couple months of use and I had to replace it with a brand new fan. Now my second fan is trying to burn out on me. All the grounding wire in the RV is in good shape, I have no issues with the other 12 volt accessories or any of the electrical for that matter. So why do these cooling fans keep going out on me???? I wonder if the generator or house battery has anything to do with it. Since the house battery fluctuates in power levels frequently with the use of lights and so on if this could be causing the fans to burn out and need frequent replacement. Or a power surge when I start the generator??? The generator pulls about 360 cold cranking amps when I start it up. The RV is plugged into shore power most of the time and the generator is only started for maintenance and in power outages. I replace the fans they work for a while but then burns out again. This will be the second fan I've gone through this summer. I know being exposed to the elements back there might have a slight factor in this. 😆Maybe I need a special kind of fan for this purpose or just plug a regular 110 AC fan in back there??? Any case it's a mystery to me so I could use your feedback. Thanks

[cimplexsound]

[Old-Biscuit]

What kind of fan are you using?

WHERE is that fan mounted....next to burner area?

Looks like fan is wired 'directly' to DC power supply.....no thermostat, no On/Off switch, no in-line 1A fuse......running continuously???

Some fans are 'polarity sensitive'.....

12V DC System from batteries or converter can be 10.5V to 13.5 V and NOT cause issues.


You stated:
Found a more level spot for the RV where the fridge works much better now.
I would hope so.......off level operation will KILL an absorption fridge due to lack of coolant flow and overheating!

[cimplexsound]

I've never seen a person use an inline thermostat with these fans. The whole DC electrical system is fused protected, but that gives me an idea. These are just standard cooling fans like what you would have in a desktop computer.

[Skip426]

Picture is a little to close up to see the installation , but it appears you have boxed in the draw side of the fan .

Norcold fridges use ; Mechatronics fans P/N F 1238M12B , a brushless fan with ball bearings , a single fan on 2 door models and two on the 4 door fridges.
I've rescued several of these fans while helping friends with residential fridge installs , many are 10 years old and still perking along . In there factory installation they are thermostatically controlled so they don't run constantly.
Installed 1/2 way up the rear of the fridge they are in a free flow chimney of air .
They don't use any voltage control, so run on whatever the converter charger puts out .
Constant duty may be part of the short lifespan , but with the way the fan is mounted , lack of air flow on one side of the fan , may be causing the blades to wobble , taking out the bearings .
So maybe a different fan location , with more even inlet side flow would help.

[Old-Biscuit]

Originally Posted by cimplexsound

I've never seen a person use an inline thermostat with these fans. The whole DC electrical system is fused protected, but that gives me an idea. These are just standard cooling fans like what you would have in a desktop computer.

Factory/OEM fans use a thermostat attached to condenser fin. Turn fan ON at 130*F FIN temp and OFF at 115*F FIN temp

Fan thermostat kits available via on line shopping.

Some even use an ambient air temp sensor vs condenser fin temp
They turn fan(s) ON when ambient air temp is above 85*F ---turn fan(s) OFF when air temp drops below 70*F

Both installations have a 1A in-line fuse........RV system fuse to fridge is 15A , too high for fan issue protection



Still wondering WHERE your have fan mounted????????

[gruelens]

These fan units work real well for airflow behind an absorption refrigerator.

https://www.arprv.com/products.php#5-blower-fan

[spyderRV]

I approached this in a different way. I put 4 exhaust fans on the roof vent which comes on with the fridge. They are series / parallel so they run slow and quiet. The fridge will run around 32 degrees in South Texas.

[SCVJeff]

I did the same thing but used IP68 rated PWM fans fed off a PWM "dimmer" so I can turn them from 25% all the way up.

OP- I'm confused about the statement "trying to burn out".. How do you know that?

[MSHappyCampers]

This is what I used. They have a 6-year manufacturer's warranty and rated at 150,000 hrs MTBF (mean time between failures)!

https://www.amazon.com/dp/B00KESS6O0..._t3_B00KFCRATC

[Arizona]

I've been using for many years running continuously summers in Arizona and never had one go out.
Maybe a third one will be the good one and maybe don't play the lottery for a while.

[cimplexsound]

To answer a question a lot of you are asking. My cooling fan is mounted to a metal CPU cooling cage (like the kind that is mounted to a CPU in a computer) that sits on the bottom of the fridge just inside the outside access door. Fan is wired directly into the 12 volt accessory port of my inverters DC system

UPDATE:


I was tinkering around with my fridge fan last night and discovered something interesting. I took the product identification sticker off the back of the fan to discover it has bushings that can be lubricated. I drop a couple of drops of oil onto the bushings and now the fan works perfect no problems. In fact the fan almost tried to eat my fingers. 😆 The problems is insufficient lubrication at the factory which shortens the life span of these cooling fans. I always have to lubricate the bushing on the blower motor of my rooftop AC unit once every few month too. The fans are made to be able to run constantly. Remember they are designed for computers which sometimes never get turned off. Seems the factory need to learn to use more lubricant if their going to sell a good long lasting product. So I put some lithium grease down in the bushing of the fan and put a round smiley face sticker on the back of the fan to seal it back up. All fixed now. The fan is like a Ferrari now it wants to get up and run off!!!! 🚗 I try to always remember the golden rule of mechanics. All moving parts need sufficient lubrication.

[SCVJeff]

That's a pretty common fix with those impregnated bushings. In that service you want something with a high IP rating that can take the environment; dust, temp extremes, etc. the Noctra fans are designed for this service.

Also, in a perfect world you want to DRAW air out, not push it in. That can create turbulence in the rear cavity and that creates dead spots along the cooling unit

[SCVJeff]

(Dup)