bills
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Post by bills on Apr 18, 2020 20:10:44 GMT
I have a CK-2-C16 Monitor Top that has been running perfectly for several years. Now it seems to stop running after less than a week. I discovered that if I turn it off and then on it comes back on and runs normally until the next failure. I will say that the compressor seems to start normally and there are no unusual sounds relay chattering compressor noise. When it runs it runs perfectly. So, I've been poking around the forum and was reading about the overload protection. So after it failed I paid particular attention to listen and feel for the overload being rest when I turned the switch to off and later compared to turning the refrigerator off after a normal cycle. I believe that I could hear the overload resetting after failure. It seemed definitely different from when I cycled it after a normal shut down. I will also say that there have been no unusual smells so, I would think I don't have a refrigeration leak. So, where should I look for a cause of the overload tripping? Is the relay the likely suspect? Would it be possible to clean up contacts? Or am I just better to replace? I do worry about disturbing the wiring but will do so if I have to. Thanks for any pointers that you can provide. FYI - I was unable to add an attachment as I received an error indicating that there was no space available. Thanks.
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Post by elec573 on Apr 19, 2020 3:09:06 GMT
I think you’re on the right track , the overload is tripping for a reason.
Its function is to protect the motor from too high current going into the motor.
Yes the contacts can be worn and causing a high arc when opening or closing.
The contacts should come to gather fast and the surface area should meet evenly and as precisely as possible.
But after so many years of operation the electric arc where’s away the contacts , and sometimes can stick or not make a good solid contact and creating high current and causing the
overload to trip .
You can check the contacts and clean but be careful there’s not much of a contact there to begin with.
After 80 plus years it’s bound to be less than new .
The wiring I would check also mine was very crispy before I changed it. You probably well have to anyway as soon as you start moving things around to check them
out it we’ll crack and fall apart.
As far as pictures we are out of space on this site and use a third party to post pictures.
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Post by ckfan on Apr 19, 2020 13:22:10 GMT
Yeah, it really sounds like the relay isn’t doing it’s job. I do know that a few members have rebuilt them and put new contacts in them. I know from personal experience that if you try to do any work that is connected to the wiring, it will crumble. There is a guide posted here on how to re wire a CK though.
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bills
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Post by bills on Apr 19, 2020 18:02:33 GMT
Thanks for your advice. Should I consider going with a new relay. The SUPCO RO81? I think it has overload protection built in correct? Does the original overload protection (that integral with the switch) ever go bad, as in trip at normal current? So, if I was to install the new relay with overload protection, could I bypass the original safely? Or do we leave both in place? I'll likely take a look to see if I can clean up the original relay to fix the problem but, wanted to understand potential options before proceeding. Thanks again very much for your guidance.
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Post by turbokinetic on Apr 20, 2020 13:57:17 GMT
Thanks for your advice. Should I consider going with a new relay. The SUPCO RO81? I think it has overload protection built in correct? Does the original overload protection (that integral with the switch) ever go bad, as in trip at normal current? So, if I was to install the new relay with overload protection, could I bypass the original safely? Or do we leave both in place? I'll likely take a look to see if I can clean up the original relay to fix the problem but, wanted to understand potential options before proceeding. Thanks again very much for your guidance. Hi Bill. The RO81 does have its own overload protection; but I would not try to alter the control and remove the overload protection parts. It's a complex instrument and there's a good chance of damaging the rest of the control. Most CK machines have two overloads in them already. One is an automatic-reset device in the start-relay; and the other is the meting-alloy manual reset device in the control. If the control melting-alloy device is tripping, it means that the auto-reset protector in the start-relay must not be functioning, or possibly there is a short in the wiring at the start-relay. I would definitely investigate the start-relay first, and then move on from there. |
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bills
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Post by bills on Apr 20, 2020 17:39:51 GMT
Thanks for that advice. Good to know that the overload in the melting alloy overload is pretty reliable. I won't go looking to create more problems.
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Post by cablehack on Apr 21, 2020 10:20:34 GMT
I'd be curious to measure the power consumption first just to make sure it's normal. Something like the start winding always being in circuit is the kind of fault I have in mind causing an overload to trip, even though the motor appears to run normally.
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Post by turbokinetic on Apr 21, 2020 12:50:24 GMT
I'd be curious to measure the power consumption first just to make sure it's normal. Something like the start winding always being in circuit is the kind of fault I have in mind causing an overload to trip, even though the motor appears to run normally. Definitely. The start-relay sticking, or a fault in the wiring could cause this. |
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bills
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Post by bills on Apr 21, 2020 14:20:26 GMT
Thanks for that advice. After reading the forum over the weekend I put a watt meter on order. Hopefully, be here before long. What is considered "normal?"
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bills
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Post by bills on Apr 21, 2020 15:17:20 GMT
Thanks for that advice. After reading the forum over the weekend I put a watt meter on order. Hopefully, be here before long. What is considered "normal?" Also I will mention that this continues to be intermittent though is occurring roughly 1 time per day now. I'm hoping the Watt Hour meter will let me capture peak draw. Thanks. |
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Post by ckfan on Apr 22, 2020 0:10:54 GMT
I would turn it off now. Running it like this could damage the motor. I would say something in the neighborhood of 160 watts would be considered normal. I’ve seen as high as 200 when you first turn it on when it’s warm. Look at the data plate too. It should give you the full load amps which is what the motor shouldn’t go over.
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bills
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Post by bills on Apr 22, 2020 12:30:56 GMT
Ok makes sense. I put the watt meter on yesterday and it was 160 at the low and 182 at the high but has not failed. I had hoped to catch the failure but, as you recommend not good to risk damage to the motor. I'm waiting the arrival of a relay and I'll have to dig in. Appreciate the advice from everyone and will consult the posts for help. Lot's of good information here. Thanks.
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Post by turbokinetic on Apr 22, 2020 13:14:12 GMT
Ok makes sense. I put the watt meter on yesterday and it was 160 at the low and 182 at the high but has not failed. I had hoped to catch the failure but, as you recommend not good to risk damage to the motor. I'm waiting the arrival of a relay and I'll have to dig in. Appreciate the advice from everyone and will consult the posts for help. Lot's of good information here. Thanks. Hi Bill. Your wattage is right where it needs to be. The amp draw should be close to the nameplate rating. It may go up to about 125% of that rating during the first part of the run cycle; but when stabilized it should be within the rating. If the start relay malfunctions, you will probably see 7 or 8 amps or more. Normal running would be around 3 if I remember. |
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bills
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Post by bills on Apr 23, 2020 12:35:11 GMT
Thanks for that. It seemed close to what we expected. I've got it unplugged now to prevent any additional damage and once my replacement relay comes I'm planning to take a look at the relay to see what I can and if it potentially can be cleaned up. Otherwise I'm going to go with a replacement relay and see how it goes. Thanks again for your help. I'll try to post on results but it might be a bit of time.
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Post by elec573 on Apr 24, 2020 2:41:25 GMT
I’d also recommend a rewire, as soon as you move the relay the reasons we’ll become apparent.
Read ckfans how he rewired his Ck .
If you’re going to replace or work on the relay you miles we’ll go the extra time and replace the wiring.
It we’ll be worth the effort.
It’s not that difficult and we are here to walk you through it if you have questions.
But do a little research on it view the forum examples!
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