Refrigerator Pt. 2

[Steve Kraus]

The patient: GE Profile side-by-side, about a dozen years old, no fancy electronic controls that I am aware of

The symptoms: Nice and cold on the freezer side. Barely cooling on the refrigerator side

Direct Cause: Poor air flow. The control damper appears open and no connecting vents are blocked.

Previously based on reading some online advice I was given to suspecting that the defrost system (timer, heater, kill-thermostat) may have been faulty and allowed the evap to fill with ice and block airflow.

I finally was able to clear out all the food from the freezer side, remove the shelves, shelf rails, and various rear covers. Bottome line is that the evaporator is *not* plugged with ice so that was a dead end.

However I did notice that the circulating fan inside the rear of the freezer sometimes doesn't come on when the compressor and condensor fan do. I presume these always run together. Also sometimes it seems to spin sluggishly.

So now I am definitely on to something. When it wasn't turning I could get it going by giving it a push by hand.

But here is where I am still a little puzzled and may need advice:

So far as I could tell by turning it, the fan turns completely freely. So it's not like it's bound up. It spins freely and you can feel a little "cogging" effect from magnetic interaction. This is one of those small induction motors where there is a single coil offset to one side in the magnetic structure and has just a simple rotor. And you could feel that the power was on.

So why would it not start or run sluggishly? It's getting power and it's able to spin freely...what more is there? If friction was high I should be able to feel it. And if power wasn't there or the coil was intermittent that would be apparent too. I don't get this sluggish business.

So I wonder if replacing the motor would even cure it. Before I do that I wonder if it's not getting full voltage for some reason. As I said so far as I know this fridge has no electronics. Could there be some provision for regulating fan speed? This isn't the kind of motor that you'd do that via controlling the voltage anyway. And if it's turned on via the same thermostat switch contacts that turn on the compressor then it can't be that some contacts somewhere are bad giving it poor voltage.

I think before I go ordering a new fan I should see if I can connect it directly to AC and eliminate any issues with the power getting to it.

Speaking of fans I temporarily put a muffin fan inside the fridge side under the inlet damper to pull more air in (I cable-tied it in place) so I can maintain proper temp on that side until this is all resolved. That's working well for now but I still need to fix this thing.

[Ed Pawlowski]

BINGO, we have a winner.

DUH, if the motor does not turn it is defective. Period. It has very low power and if the bearings are going bad, it will not run feely. You can stop those thing with the pinky finger of a 1 year old. BTDT a few times.

So again you proved the fan is not working and is needed. Replace it and be done with it. Should be readily available at any appliance parts place or

[The Daring Dufas]

That type of fan motor should offer no mechanical resistance at all with the power leads disconnected. I just pulled one out of an old 'frige and simply re-oiled the bearings and saturated the felt reservoirs with oil and the thing is running fine now.

TDD

[DanG]

These fans are well under $20 at an appliance parts house. Let's think about a fan expected to run in sub zero or low digit temperatures. I can't imagine any reason for the lubricants to become sluggish, can you?

[Tony Hwang]

Hi, Your motor is worn out. Even if cleaning lubricating, etc. won't make it last longer. It's not worth the effort. Replace it. Time is money. Fiddling it takes time.

[Steve Kraus]

Yeah I guess I'll just order one. Just seemed strange that it's unable to overcome what to my finger feels like no friction at all. Thanks.

[Stormin Mormon]

I've done a couple like that. Such as my own refrig. Often, it's easier to just put in a new fan, and know it's good for years.

[Stormin Mormon]

Since you seem to have a source of parts, replace the fan motor. And it will give you years of good service.

[Steve Kraus]

Actually it's $120-130 based on two online sources.

Just to be sure, this is not the kind of motor that uses a capacitor, right? I don't want to buy a new motor and find out that the problem was really a 5 dollar cap that's gone bad.

[Stormin Mormon]

No cap. Evaporator motors, I've never seen a cap.

[Steve Kraus]

I just wanted to follow up in case it can be of help to someone.

In fact despite the fact that this refrigerator (about a dozen years old) has no electronic controls there *is* actually a bit of circuitry with the evaporator motor. If I had to guess I'd say that maybe they drive the actual motor at a higher frequency to go faster while retaining the general simplicity of an induction motor.

It could be that the circuitry rather than the motor itself was the failure point since it sure didn't seem like the bearings were bad and there really isn't much else to the motor...just the one coil. On the old motor I could stop it easily by grasping the shaft with my fingers and while you can do that on the new one the difference is that the old one could stay stopped when you let go and sometimes needs a push to get going again. It does spin freely and did even while cold so the drive circuit could be the issue.

Now that it's out I'll play with it and see what freq is going to the motor coil. The label says it's supposed to turn at 2600 RPM. My strobe says more like 2500 but either way that's not the 60 Hz multiple I would expect of a directly driven motor.

As for the repair, it was far more complex than it needed to be thanks to GE's design. While everything comes apart and unplugs nicely the fact that the entire evap coil assembly is clipped to and is held by the plastic bracket that holds the fan motor is, IMHO, ridiculous. I suppose a pro might not worry about it and just let it hang of its own accord but I could not take a chance like that so after all the other covers and shelf rails etc. were out I got some bailing wire and tied some support lines between holes in the evap coil frame and the shelf rail screws, then had to struggle to get the thing that holds the motor out past them. At least I didn't have to worry I was stressing the refrigerant lines. Other than that it's pretty straightforward.

It's all back together now and temp is coming down nicely. I won't know if the actual problem (too warm on the fridge side) is actually solved for a few days I guess. However for now as soon as the freezer temp is back down where it should I'll resume powering the muffin fan I put on the fridge side to pull more cold air in. Once the fridge temp is down where it should be I'll pull the supplemental fan out and we shall see if the new fan motor on the freezer side has cured the problem.