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Post by turbokinetic on Nov 18, 2018 21:41:04 GMT
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Post by ckfan on Nov 18, 2018 22:24:19 GMT
That’s really neat to see that work. I already knew how it worked but I didn’t know that it had to get red hot to trip! It seems like it took an awful long time to trip when in a stalled condition though.
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Post by turbokinetic on Nov 18, 2018 22:59:59 GMT
That’s really neat to see that work. I already knew how it worked but I didn’t know that it had to get red hot to trip! It seems like it took an awful long time to trip when in a stalled condition though. Hi Ray. It did seem to take a long time, but remember these motors are designed differently from modern ones. There's a lot more thermal mass to them it seems. |
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Post by ChrisJ on Nov 29, 2018 0:39:36 GMT
That’s really neat to see that work. I already knew how it worked but I didn’t know that it had to get red hot to trip! It seems like it took an awful long time to trip when in a stalled condition though. Hi Ray. It did seem to take a long time, but remember these motors are designed differently from modern ones. There's a lot more thermal mass to them it seems. The compressor is drawing 12-15A @110-125v. Does that heat the solder pot faster than the same current at a low voltage? |
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Post by turbokinetic on Nov 29, 2018 3:24:55 GMT
Hi Ray. It did seem to take a long time, but remember these motors are designed differently from modern ones. There's a lot more thermal mass to them it seems. The compressor is drawing 12-15A @110-125v. Does that heat the solder pot faster than the same current at a low voltage?
Yes sir it would! The heat generated is proportional to amps through the coil.
It's based on ohm's law in the form P=(I²R) In other words, (power) = (current [squared]) times (resistance). The power dissipated would determine how fast the solder pot heats up, and it only matters the current and resistance. The resistance is fixed by the heater coil size.
I can't remember if I mentioned it, but I installed a second, external modern overload breaker in the CA I got running. I just think the solder pot takes too long to melt. The overload is just an RO81 without using the start timer. That overload trips in about 5 seconds, with a 4 minute off time. That is plenty of time to dissipate the heat between cycles, if it gets stuck in a cycling condition.
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Post by coldspaces on Nov 29, 2018 3:45:56 GMT
The compressor is drawing 12-15A @110-125v. Does that heat the solder pot faster than the same current at a low voltage?
Yes sir it would! The heat generated is proportional to amps through the coil.
It's based on ohm's law in the form P=(I²R) In other words, (power) = (current [squared]) times (resistance). The power dissipated would determine how fast the solder pot heats up, and it only matters the current and resistance. The resistance is fixed by the heater coil size.
I can't remember if I mentioned it, but I installed a second, external modern overload breaker in the CA I got running. I just think the solder pot takes too long to melt. The overload is just an RO81 without using the start timer. That overload trips in about 5 seconds, with a 4 minute off time. That is plenty of time to dissipate the heat between cycles, if it gets stuck in a cycling condition.
The 4 min. off time on the R081 overload is great. I too have stolen just the overload out of them. Nice video! |
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Post by turbokinetic on Nov 29, 2018 4:57:55 GMT
Yes sir it would! The heat generated is proportional to amps through the coil.
It's based on ohm's law in the form P=(I²R) In other words, (power) = (current [squared]) times (resistance). The power dissipated would determine how fast the solder pot heats up, and it only matters the current and resistance. The resistance is fixed by the heater coil size.
I can't remember if I mentioned it, but I installed a second, external modern overload breaker in the CA I got running. I just think the solder pot takes too long to melt. The overload is just an RO81 without using the start timer. That overload trips in about 5 seconds, with a 4 minute off time. That is plenty of time to dissipate the heat between cycles, if it gets stuck in a cycling condition.
The 4 min. off time on the R081 overload is great. I too have stolen just the overload out of them. Nice video! Thanks Gill. I used the OL from the 1/4 HP version (RO41? can't remember) for the motors for mine and Travis's belt-drive Frigidaires as well.  |
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Post by ChrisJ on Nov 29, 2018 10:01:58 GMT
I have the specs to that overload somewhere but I recall it trips after a short time at 4 amps or so.
Supco had responded to an email of mine about it.
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Post by birkie on Nov 30, 2018 0:17:37 GMT
It's based on ohm's law in the form P=(I²R) In other words, (power) = (current [squared]) times (resistance). The power dissipated would determine how fast the solder pot heats up, and it only matters the current and resistance. The resistance is fixed by the heater coil size.
I can't remember if I mentioned it, but I installed a second, external modern overload breaker in the CA I got running. I just think the solder pot takes too long to melt. The overload is just an RO81 without using the start timer. That overload trips in about 5 seconds, with a 4 minute off time. That is plenty of time to dissipate the heat between cycles, if it gets stuck in a cycling condition.
Twinkle twinkle little star, power equals I squared R. I agree that the overload looks like it takes too long to trip. I kind of like the overload on the DRs better. They seem more responsive, and are even a bit adjustable. |
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Post by ChrisJ on Nov 30, 2018 15:53:11 GMT
Is it too slow, or is that completely intentional?
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Post by turbokinetic on Nov 30, 2018 17:53:19 GMT
Is it too slow, or is that completely intentional? It's hard to know. There are published trip curves for most motor overload relays, but not sure that you would be able to find one for this integrated design.
In my opinion, it seems too long. If the motor was energized, stalled, from a cold condition I feel like the overload would trip before the motor was damaged. However, if the motor was mildly overloaded and gradually overheated it would likely not protect the motor.
This control came from a CK which also had a bimetallic overload in the start relay, so this one could have been intentionally set high, to encourage the auto-reset one to trip first so that an auto reset would be possible.
Just my conjecture, of course...
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Post by ckfan on Nov 30, 2018 19:11:33 GMT
The CKs originally came with a type E relay which did not have the bi metallic overload built in. Hence why these controls had an overload. Later flat tops and spacemakers and so on had the type R relay which is what you probably had on yours. A lot of the type E relays got replaced with a type R at some point. Two of my machines had that work done. I have a 35 flat top which still uses a type E though. It’s very similar to what the CAs used. It makes a very definite clunk when it turns on. It’s currently purring away in my kitchen.
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Post by Travis on Nov 30, 2018 19:17:53 GMT
What model was the CK? It could be that the original relay was changed for a type R in it's service life.
I see the overload rating either 3.4 or 5.1 amps
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Post by turbokinetic on Nov 30, 2018 19:38:27 GMT
The CKs originally came with a type E relay which did not have the bi metallic overload built in. Hence why these controls had an overload. Later flat tops and spacemakers and so on had the type R relay which is what you probably had on yours. A lot of the type E relays got replaced with a type R at some point. Two of my machines had that work done. I have a 35 flat top which still uses a type E though. It’s very similar to what the CAs used. It makes a very definite clunk when it turns on. It’s currently purring away in my kitchen. Hi Ray. It's the one shown here: monitortop.freeforums.net/thread/1425 which does have a GE rebuilt sticker on it. I don't have a picture of the sticker and won't have access to it anytime soon due to work obligations. What model was the CK? It could be that the original relay was changed for a type R in it's service life. I see the overload rating either 3.4 or 5.1 amps This one had the larger size heater in it, so that would be the 5.1A size. When I broke the control for my CA (grumble) and used parts of a "parts" control to fix it, I noticed the CA had a smaller heater coil in it. I kept that with the CA. |
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Post by Travis on Nov 30, 2018 19:59:09 GMT
The control I gave you was from a CK1. If it was a larger heater, it wouldn't have protected the unit.
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