It Works, But Is It Safe? Novice Looking For Jury-Rig Peer Review

Thread Starter

JDavis36

Joined Mar 25, 2020
2
I have just completed a repair of a Danby Wine Fridge that required (or at least precipitated) some unorthodox solutions. My qualifications are limited to at-home tinkerer and patient google reader, so I'd basically like to explain what I've done and allow someone who knows what they are doing to say either "that seems like a reasonable solution" or "remove power to that device immediately before your home incinerates".

The fridge was making a tremendous noise, which I determined was being caused by the aging condenser fan. The fan (and perhaps its manufacturer) is discontinued and I could not find available replacements online. Some internet browsing convinced me I could simply replace the fan with a PC fan of the same size, so I ordered a PC fan of the same dimensions, requiring the same amperage, and producing similar volume air flow as the old. I cut the power source running to the old fan and spliced the positive and negative wires to the new fan. The PC fan came with a 3 pin connector so I disregarded the signal wire. After getting the new fan mounted in place and pleased with my work I plugged in the fridge...Instant fire.

Post-mortem showed that the fireworks were a result of the small resistor embedded in the positive wire to the PC fan having exploded as soon as I plugged in the device (I used the optional low-noise wire attachment that can with the PC fan and has a small resistor in the circuit to lower the fan speed). After a period of confusion and googling, I determine that the old fan was built to take a direct 100-125AC current, meaning that the fan power supply that I had just sent to the 12V PC fan and its poor resistor was 120AC.

The resistor appeared to have taken the brunt of the load and the fan seemed fine so I got to thinking of a solution. I had several old AC adapter computer chargers and the like sitting around the house. I found one made to power a computer monitor that converts ~120AC to 12V DC, up to .9 Amps. The amperage requirement of the fan is .09 Amps. I cut the cables on either side of the AC converter inline box and spliced the box in between the fan power supply and the fan. I re-powered the fridge and the new fan is now humming.

So - the fridge appears to be functioning fine with this setup, but I am apprehensive to simply tuck in into its space in the counter. Are there any concerns with using a consumer electronics AC converter box in a permanently-powered role within an appliance? The AC converter is rated to output 12V DC, but up to 10X the amperage required by the fan - is there a risk of frying the fan? Any other issues I'm not experienced enough to know to ask about? I'd really like to avoid repeating the fire show that took place in round 1.

Appreciate any thoughts on this.

Best
 

dl324

Joined Mar 30, 2015
10,498
Welcome to AAC!
The AC converter is rated to output 12V DC, but up to 10X the amperage required by the fan - is there a risk of frying the fan?
No problem with the amperage, but I'd be concerned about how you did the splices.
Any other issues I'm not experienced enough to know to ask about? I'd really like to avoid repeating the fire show that took place in round 1.
If you don't have a DVM, get one. Next time, don't make assumptions about voltage requirements. You were lucky this time. You might not be next time.
 

ebeowulf17

Joined Aug 12, 2014
3,274
Personally, I'd be a tiny bit concerned about the integrity of the motor, wondering if there was any internal damage besides the burnt resistor. Might be fine though, and the rest sounds good, as long as you have good, tight splices that are well insulated and protected now.

How did you make splices? Crimp terminals, screw terminals, wire nuts? How did you protect them? Heat shrink, electrical tape?
 

Thread Starter

JDavis36

Joined Mar 25, 2020
2
Thanks for the input. To be honest, I don't think my splices would get a stamp of approval from anyone here. They are just twisted ends sealed with electrical tape. Given that every response has pointed out that the splices are the point of concern, I will be redoing all of the splices with insulated butt connectors and heat shrink before returning the fridge to its home.

Really appreciate all the input.
 

dl324

Joined Mar 30, 2015
10,498
I will be redoing all of the splices with insulated butt connectors and heat shrink before returning the fridge to its home.
I'd solder them and cover them with heatshrink. If you use the solderless connectors, make sure you crimp them properly.
 

Alec_t

Joined Sep 17, 2013
11,137
Make sure your power adapter/wiring has adequate ventilation and is not positioned adjacent anything which might run hot.
 

MisterBill2

Joined Jan 23, 2018
5,754
Since the appliance provides 120 volts AC to power the fan, and since there are hundreds of fans on the market , a bit more investigation will find you a fan that is directly powered from the AC mains and simply needs to be connected.
And I am amazed that in reading the label on the noisy fan you did not note the voltage rating, which is the very most important thing when seeking a replacement part.
 
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