tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Sept 20, 2018 23:18:19 GMT
My CK has been giving stellar service for the last 35 years of my ownership, but has recently seen fit to give me fits... It refrigerates well but then occasionally will not restart itself. I'm guessing this is the "erratic operation" routine. Looking in the manual, I see that this may be the bellows on the temperature switch, is this correct? Or are there other problems that this symptom would point to?
Thanks
Paul
|
|
tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Sept 20, 2018 23:23:39 GMT
Also, as an added note, it will sometimes start after jiggling the on/off switch several times. When ut doesn't start, there will be a distinct electrical switch AC hum.
|
|
|
|
Post by ckfan on Sept 21, 2018 1:33:34 GMT
Hello and welcome to the forum. It sounds like you have either one of two things happening. Either your control is going bad or your relay is going bad. Both will cause issues but the relay problem is a little worse as it can destroy the compressor motor over time. Fortunately we have lots of threads on how to replace and repair those items and we also have a section on how to completely rewire your CK which it most likely needs unless it is one of the few unicorns I’ve seen. If you replace a part it will cause the wiring to crumble and the insulation will fall apart.
But let’s not dive into all of that just yet. First off let’s diagnose the issue. If you turn the switch to on will it try to start every time or will it do nothing until you jiggle the control? If it tries to start each time you turn it to on then the control is most likely good. The relay can also cause a compressor to not start if it doesn’t engage the start winding. The compressor will just sit and hum and be stalled. This isn’t good on it and you should immediately turn it off if it does this. I guess what I’m trying to get at is...do you think the switch is making connection each time or do you think it’s flaky?
|
|
|
|
Post by turbokinetic on Sept 21, 2018 1:47:17 GMT
Hi Tatrat. Glad you've found this forum as we can help you to get this CK up and running. The CK compressor and motor is very reliable. The problems are most likely external to the compressor. The issue needs to be resolved, because constant failed starting attempts on the compressor can eventually burn the motor.
A very helpful thing would be to record a video of the unit not starting, and then record "fiddling with" the control to make it start. You can upload it to YouTube as "unlisted" and post the link here. That way we can see it but it won't attract a bunch of unrelated views.
I want to ask some further questions about the noise it makes.
There are one of two possible scenarios.
1 - The unit tries to start up, and there is a click. After this click, there is a crackling buzzing noise from the control area. It may come and go, but it is more or less constant until you intervene.
2 - The unit tries to start up, and there is a click. After the click, there is a solid, magnetic "humming" for 20 or 30 seconds. Then there is another click, and the humming stops. After a couple minutes, the click and humming will repeat. There may be a dimming of the lights in the room associated with this failure mode.
If the scenario 1 is what you've got - the control would need to be investigated, as the main contacts are probably worn and arcing.
If the scenario 2 is more like it - the motor start relay is probably not working, causing the motor to be stalled and trip the thermal overload circuit breaker.
Hope this helps! Looking forward to hearing back!
Sincerely,
David
|
|
tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Sept 21, 2018 4:18:59 GMT
Thanks for the replies. Basically what is happening is that the unit will work for an indeterminate time, shut itself down when cold enough, then maybe 1/2 the time turn itself back on, and 1/2 time fail. when it does fail I can hear an AC hum, and then it goes out completely. I can then jiggle the on/off back and forth, and after a number of tries, eventually it will catch and run smoothly. Unfortunately this scenario will usually play out when I'm not home, or at night, and I have a defrosted unit to face. So, I'm not exactly sure of what's happening. I'll try to get a video of what it's doing (as suggested), and post that. Right now it's working again.
Paul
|
|
|
|
Post by turbokinetic on Sept 21, 2018 13:31:15 GMT
Thanks for the replies. Basically what is happening is that the unit will work for an indeterminate time, shut itself down when cold enough, then maybe 1/2 the time turn itself back on, and 1/2 time fail. when it does fail I can hear an AC hum, and then it goes out completely. I can then jiggle the on/off back and forth, and after a number of tries, eventually it will catch and run smoothly. Unfortunately this scenario will usually play out when I'm not home, or at night, and I have a defrosted unit to face. So, I'm not exactly sure of what's happening. I'll try to get a video of what it's doing (as suggested), and post that. Right now it's working again. Paul
Hi Paul. That sure sounds like a start relay failure.
The reason you can get it to try again to start is because the control switching to "off" resets the overload breaker on some of these units.
You can open and inspect the relay, if you're handy with working on electromechanical parts; or you can install an aftermarket relay in place of the original.
Often, the start contacts of the relay will wear down so that they don't touch any longer. Then this happens. You can sometimes file them smooth with a points file; and adjust the position of the contact arm so that they function again. The trick is to be very mindful of the motor's start signal requirements. It will, definitely, without a doubt, internally burn out the motor if the start and run circuits are swapped. It will also very likely burn out the motor if the start circuit does not turn off after the motor starts. So; be sure you listen and monitor the motor's current draw after any repairs to the start relay. Be sure it's working properly before letting the unit run for any length of time.
Not trying to scare you; but just be aware. The relay is a simple device. It's purely mechanical and electromagnetic.
Sincerely, David
|
|
|
|
Post by elec573 on Sept 22, 2018 2:33:26 GMT
It does sound like a relay problem. The relay is in the back down in between the fins . You we’ll have to pull it out to work on it. But I’m sure the wiring is extra crispy so
when you pull it out the wiring we’ll probably crumble . So let us know what happens.
|
|
tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Dec 2, 2018 21:38:56 GMT
Well, I managed to do the worst... the relay started to work again, so I fell for the delusion and faith of painless repair. Till that fated morning when I went into the kitchen, and heard a loud buzzing noise. The refrigerator had stopped and the compressor was very hot. I shut it down, let it cool off, and tried again... no reply. I guessing the compressor is cooked... any solutions? And is there anyone in the Los Angeles area that could help? I'm not experienced in this kind of repair, and I'd hate to see this thing go by by, as we have had a long and fruitful relationship.
Paul
|
|
|
|
Post by turbokinetic on Dec 2, 2018 23:00:27 GMT
Well, I managed to do the worst... the relay started to work again, so I fell for the delusion and faith of painless repair. Till that fated morning when I went into the kitchen, and heard a loud buzzing noise. The refrigerator had stopped and the compressor was very hot. I shut it down, let it cool off, and tried again... no reply. I guessing the compressor is cooked... any solutions? And is there anyone in the Los Angeles area that could help? I'm not experienced in this kind of repair, and I'd hate to see this thing go by by, as we have had a long and fruitful relationship. Paul
Awe I'm so sorry to hear this happened. There are one or possibly two safety devices which might have caused it to fail to re-start after this incident.
Normally, if it was buzzing or humming when you turned it off, it would have done the same when turned back on; if power were getting to it. The melting-alloy overload protector for these refrigerators only can trip a certain number of times before it starts to get iffy. Hopefully this has done its job and opened the circuit.
When you say "very hot" was it hot enough to burn the paint on the top of the unit?
Either way, you will need to troubleshoot the unit and for sure, install a new relay, such as an RO81, which would have a new overload breaker along with it as well.
|
|
tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Dec 2, 2018 23:06:58 GMT
Thanks for the re assuring note... It certainly wasn't hot enough to melt the paint, or even scorch my hand... just enough to get my attention.
|
|
|
|
Post by turbokinetic on Dec 2, 2018 23:11:03 GMT
Thanks for the re assuring note... It certainly wasn't hot enough to melt the paint, or even scorch my hand... just enough to get my attention.
That's not so awful. 
There should be several threads on here on hooking up a RO81 start relay. That would be my next step in troubleshooting it. That will bypass the original start relay and add an additional overload circuit breaker.
You will need to get the control to make contact again and it's possible it will require disassembly and repair if the overload function is damaged.
How familiar are you with electrical work?
|
|
tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Dec 2, 2018 23:13:21 GMT
David:
Not very... I work on antique motorcycles, cars and neon signs, all of which have some degree of electrical components, but I barely know how to use a meter, or soldering iron. Electronics knowledge is something that has passed me by.
Paul
|
|
|
|
Post by turbokinetic on Dec 2, 2018 23:24:00 GMT
David: Not very... I work on antique motorcycles, cars and neon signs, all of which have some degree of electrical components, but I barely know how to use a meter, or soldering iron. Electronics knowledge is something that has passed me by. Paul I see. However, if you are familiar with neon signs and antique cars, you are familiar with delicate things that require care to work on. The old wiring is going to be delicate, but it is very simple. The CK is about as simple as the Monitor Top ever was.
The control is fully mechanical. They have a delicate, gas-filled sensing tube which is somewhat easily broken. If you are careful with that tube, you can free the tube from its clips on the evaporator, and straighten it out some. Then, the control can be lifted up and out of the unit, where you can work on it. I have been successful getting them working again by carefully oiling the moving parts inside. That often allows the mechanism to work freely again. In your case, once you get the RO81 in place, the control's overload breaker will not be tripping again, and therefore if you can get it to reset one last time, you may be good for quite a while.
|
|
tatrat87
New Member
need CK starting help
Posts: 12
|
Post by tatrat87 on Dec 2, 2018 23:30:29 GMT
Thanks again... I've got to see what I can get apart without doing any damage...
|
|
|
|
Post by turbokinetic on Dec 2, 2018 23:35:03 GMT
Thanks again... I've got to see what I can get apart without doing any damage... Just be careful of the sensing tube on the control. The rest of the wiring can be replaced if needed. |
|
