Getting Wire into frige?

Went ahead and drilled a small hole near the drain. Piece of cake.....IMHO beat snaking a wire thru the drain tube...just plastic and foam. Install looks real good.

Thanks All for the input and help.

Hi Don,

Thanks tons for taking the time to write such a complete and careful description of how you did it.

Yes I have a Norcold and your description is spot on as to the configuration of my refrige.

I continue to be amazed on this forum how helpful folks are. I really appreciate everyone sharing their thoughts/experience and taking the time to respond.

Dan

Cruz-in

If you have a Norcold Model reefer, they have a magnetic door switch that is located right under the on/off button on the control panel.

Take a magnet and slide it along the recessed door lip and the interior light will turn off and on.

I installed a couple of the small blue colored fans inside my reefer,
I got the power from the circuit board wire, 12v, that is HOT all the time.

To get the small wire to the fans, I removed the control panel, I used the OEM holes to run a 17 cal cleaning rod with pointed tip jag for pushing patches, to make a hole to the inside of the reefer.

I carefully removed the light and pushed the cleaning rod thru the strafoam and into the light recess, (after some carefull calculation on angles/depths etc), then I put on a slotted tip and fed the wire into the light recess.

Ran the wire to the fans across the roof, removed the excess wire, sealed the 17 cal hole with foam from both ends and attached to the Red/white hot wire 12v (IIRR) going to the curcuit board.

Reattached the OEM lite, attached the circuit board in it's place etc.

I added 2-90mm fans in the back flue, picked up a constant 12V hot wire on the curcuit board, inside the flue, used a piggy back connector and then added a 85* attic switch that turns on at over 85* and shut off at below 85* to run these fans.

I also install a simple disconnect to the main wire curcuit to keep the power off when NOT needed.

MAKES all the difference here in the summer time, since we have very little shade trees etc.

Hope this helps,
Tia,
Don

Rationale for my approach.

As many folks have wondered why I am taking the approach I am (using a speed controller) here is the rationale.

1) I wanted to use larger internal fans so that I could move air across the full face of the fins.

2) However, especially in the fricge, I did not want the larger airflow that comes with a larger (120mm) 12 volt fan.

3) I also wanted an on/off switch.

4) Given my refrigerator setup, I had to run power in from the outside.

5) I have added an 8 inch PC fan to the external refrig. Same logic as the inside fans, this allows for the movement of air across more of the exterior fins. Like the internal fans, I do not want to run at 12 volts as that would be too much air flow.

For about $15 one can get a PC fan controller that allows one to set the speed and turn off any/all fans if need be.

Fan controller is placed behind the refrig vent and powered by a 12 volt line that turns on/off with the fridge. Other than initial setup, I do not intend to "adjust fan speeds all day"

Lastly I chose fans that can start and run on as little as 5 volts allowing for a good low speed setting.....and as someone pointed out dissipating less heat inside the frige.

Hi Team,

After rereading this thread a few times and studying my refrigerator, I am considering drilling a hole next to where the drain tube enters the refrigerator and running the wires thru there. I would then seal it up with silicon.

Figure the drain tube goes thru the wall so most likely there is nothing in the refrigerator wall to worry about hitting with the drill bit. This is also kinda clean as it it right where the fan wires are.

You all's thoughts?

Thanks
Dan

My previous small compressor fridge( 1.7 cubic foot) had no interior light, no drain. I could not get any wire inside through the factory penetrations. I used very thin wire taped tightly to allow the door seal to go over it, at the top of the fridge. I used some low density closed cell foam to help seal the wires.

That 40mm internal fan made a huge difference in cool down times and evenness of internal temps.

That Fridge failed after about 5 years and my New fridge does have an internal light with the magnetic reed switch for the light, but the 12volt source is always hot.

I found a 40mm fan which draws just 0.03amps and moves ~6cfm for this fridge. This fan has the same benefits as the fan in my previous fridge, but also allows a setting of 2 of 7 to hold the same internal temps as a setting of 4 of 7 without the fan. Without the fan the temps will range from 32 to 44f inside when shot with my IR temp gun at various points. With the fan it ranges from 34 to 36.5 f everywhere. If I turn it up to 4 of 7 a gallon jug of milk gets slushy after 24 hours.

Also external temp swings do not require fine tuning of the thermostat dial. We had temps in the low 3 digits a few weeks ago and I expected to have to turn it up higher to maintain sub 39f but found it was still 36.5f or below at a setting of ~2.2 of 7.

I let mine run 24/7.


I can hear the fan sometimes if it is very quiet and it it touching something on the door shelf. I have it hanging on the bamboo skewer with heat shrink holding it in place, and a slight adjustment allows silence again, with the door closed.

Keep in mind the fan motors will contribute somewhat to the heat load the cooling unit needs to remove. For this reason I went with the lowest amp draw fan I could find, and with such a small fridge(1.8 cubic feet), a ~6 cfm fan is plenty and there is no doubt about the performance increase with it.

I mention this because of the "if a little is good, then heaps and gobs above this level must be heaps and gobs better" mentality which permeates our culture.

I'd aim for a fan that can recycle all the volume of the air within the box no more than 3 or 4 times in one minute.

These fans vary greatly in how much Air they move for current consumed and noise made, so research in this area can also have improved results.

Here is one of the most impressive fans available, though at 120MM it might be impractical for most fridges.
http://www.noctua.at/pdf/infosheets/noctua_nf_f12_focused_flow_web.pdf
Without the provided inline speed restrictors(low noise adapters) it moves ~53 CFM for 0.05 amps. Most other fans in this CFM range will consume 2 to 3x the current and make a lot more noise.

Not sure what it draws with the LNAs installed but the fan goes from extremely quiet to inaudible. They provide two LNA's and both can be used inline.

This fan is also good at pushing air through a restriction, and in a straight line, where as most fans send air off at a 60 degree angle with 3 or 4 hotspots of airflow. I have one attached to my condenser, pushing air, and the duty cycle dropped with this lower cfm fan pushing air compared to the provided higher cfm fan pulling it through the condenser.

Much much quieter too.

KD4UPL wrote:
I'm curious, what's with putting fans in the fridge? Is the fridge not staying cool enough? Does it help it use less gas?
My 6 cu ft. Dometic is never over about 35 degrees and that's on the middle setting. I don't have any fans.

Have you checked the temp at various levels in your fridge? The purpose of the fans is to circulate the air, keeping the temp more uniform throughout the cabinet. The fin mounted fans also reduce frost buildup, allowing the fridge to run more efficiently. It's not uncommon to find that you can run the fridge at a warmer setting while still maintaining the same internal temp after installing an internal fan or fans.

In reference to the drain hose, the trap style and restriction style outlets have both been mentioned, and I agree, the trap and restriction should definitely be maintained. The restriction style outlet is what I have, so I poked a very small hole in the hose an inch or so above the restriction that fits tightly around the wire sealing it where it exits the hose, leaving the restrictor untouched. In order to do that, I fished the wire in from the bottom of the hose to the top, rather than the other way around.

It took two pages before we got the final clue. :W

Inside my fridge there are two voltages available.

1) 5 volts that goes to what I believe is a temp sensor.

2) 12 volts that goes to the light. The 12 volt is only on when the door is open and shuts off after a few minutes of the door being open.

As far as picking up the 12 volts from the door-light switch. This is interesting. There is NO traditional switch on the door. In fact careful examination shows no switches at all on the door or jam. However when the door gets about an inch from being closed, the interior light goes off. So something is sensing the door being open or closed. I suspect this is done via a proximity sensor. However, there is no access to it or its power source from inside the fridge.

Hence my need to bring in 12 volts to run the fans. As long as I am bringing in the 12 volts from the outside, it it fairly easy to run them, and the outside fans, off a simple PC fan controller. This allows on/off control and speed control.