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Post by coldspaces on Aug 22, 2013 17:28:10 GMT
Just uploaded most of the rest of the work on the Type R relay.
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Post by coldspaces on Sept 2, 2013 5:03:17 GMT
Here is a video of the flat top. You can hear the sound the Mars relay makes. May not be exactly the same as the original but I still like it better then the PTC relay. As you will see I was able to unplug it and then plug it in right away and it starts just fine without waiting for a PTC relay to cool. Should save a lot of overload tripping if the power supply short cycles. 
And here is one of the GE Spacemaker with the Type R relay originally. I did not try to short cycle it as the cap tube system would need to balance out first.  |
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Post by ChrisJ on Sept 2, 2013 5:09:30 GMT
The Spacemaker uses a cap tube?
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Post by coldspaces on Sept 2, 2013 5:34:54 GMT
The Spacemaker uses a cap tube? Yes it sure does. Here you can see there looks to be a strainer at the end of the condenser coil and then you see the cap tube leaving it.  |
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Post by cablehack on Sept 2, 2013 23:42:50 GMT
The sound of the CF starting up is a lot like the CA. That sudden kick in the guts, it comes up to speed, and the relay drops out. The sound of the compressor running isn't hugely different either, though the CA does sound a little quieter, but I suspect that's mainly because it's out in the open.
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Post by coldspaces on Sept 3, 2013 1:06:25 GMT
Camera was so close when I did the videos it picked it up louder than it is with the cover on. Normally the room has to be pretty quite for me to hear the 38 at all.
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Post by ChrisJ on Sept 11, 2013 14:57:08 GMT
I'm considering converting my CA-A machine over to a mechanical relay.
While evacuating it I turned it off for a bit and decided to restart it, too soon for the PTC relay and it did some weird things. I immediately turned it back off and waited a little longer. What bothers me is, the compressor has an unloader and I want to be able to actually make use of it and with a solid state relay thats not going to ever be possible.
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Post by coldspaces on Sept 11, 2013 18:46:43 GMT
I'm considering converting my CA-A machine over to a mechanical relay. While evacuating it I turned it off for a bit and decided to restart it, too soon for the PTC relay and it did some weird things. I immediately turned it back off and waited a little longer. What bothers me is, the compressor has an unloader and I want to be able to actually make use of it and with a solid state relay thats not going to ever be possible. Great observation chris, since the compressor unloads itself the mechanical relay will restart it right away. If you would have had an amp meter on your compressor you should have found that only the run winding was drawing any current when it did weird things. The PTC relay had not cooled of so the start winding could be energized. |
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Post by ChrisJ on Sept 11, 2013 19:09:52 GMT
Either that or the start winding did get power but not enough and not for long enough.
The motor did start, but it sounded real slow. Like 1 rotation per second slow.
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Post by coldspaces on Sept 11, 2013 21:39:07 GMT
Either that or the start winding did get power but not enough and not for long enough. The motor did start, but it sounded real slow. Like 1 rotation per second slow. Could it be that the rotary compressor in the CA might try to run slow with just the run winding energized? |
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Post by ChrisJ on Sept 11, 2013 21:52:21 GMT
Either that or the start winding did get power but not enough and not for long enough. The motor did start, but it sounded real slow. Like 1 rotation per second slow. Could it be that the rotary compressor in the CA might try to run slow with just the run winding energized? Na, I think it got just enough power to get spinning but not enough to get up to speed. I don't know exactly how these motors work but I know the start winding has something to do with getting a rotating field. By the way, do you have the part numbers for the overload and relay you used? |
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Post by cablehack on Sept 11, 2013 23:30:08 GMT
The motor did start, but it sounded real slow. Like 1 rotation per second slow. Classic symptom of an induction motor with the start winding not powered. It sits there drawing lots of current with the armature turning ever so slowly. |
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Post by coldspaces on Sept 12, 2013 0:50:15 GMT
By the way, do you have the part numbers for the overload and relay you used? Relay was the Mars 27002 it was the closest to the amp ratings I could find for my N relay. The R relays were the same ratings as the N from what I have read. The CA manual states that the form A & B factory relays were not interchangeable but were both replaced by the M1A62 type R relay. The M1A162 was the part # on my N relay also. So it looks like even the CA machines had the same relay as most and should work with the same Mars relay I used. As far as an overload I used an NOS Klixon #MRK-40 HX, it crossed to a Tecumseh # 83504 It was used on the pancake compressor model P91 and others. The P91 was replaced by the AE1336A is how I decided my old overload was for an 1/8 hp compressor. Aftermarket overloads are commonly sold by the lock rotor amps of the compressor. The CA manual stats that the loked rotor amps of all CAs was 13.5. Supco's OV 32 is for compressors with LRA's of 12-13.5 amps, 120 volt 1/20-1/15 hp compressors. Mars Equivalent 35004 The OV34 is for LRA's of 14-15.5, 120 volt 1/10-1/8-1/6 & 1/5 hp compressors. Mars Equivalent 35007 I think I would try the smaller of the 2 and you can always go up if it trips to soon. Keep in mind though these will not sense any heat from the machine , only amp draw as they are not mounted to the compressor shell. |
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Post by cablehack on Sept 12, 2013 1:10:46 GMT
The R relay was the later replacement for everything used in all the CA and Scotch Yoke models. It has internal overload protection, making that in the control no longer essential.
Note that the only difference between the CA form A and B relays (type E3) is the A relay was mounted horizontally and so required a different contact tension to retain the correct sensitivity. However, when the R type is used to replace it, a bracket is supplied to mount it vertically.
So anything equivalent to the 1/8hp R relay will do for the CA's.
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Post by blackhorse on Sept 28, 2014 17:46:25 GMT
I do not like the PTC relays for all of the reasons mentioned, and because they have been much more prone to failure than the mechanical relays. They can fail from the conductive coating on the disc failing, the disc can shatter, they can short out and never disconnect the start winding. They have been the subject of recalls for setting the kitchen cabinets on fire. And these are the factory-spec ones the refrig's came with, not maybe-misapplied replacements. I have replaced a boatload of them.
Now I will make some enemies.
I put a run capacitor and a Klixon overload in the original relay housing of my CK in the kitchen over a year ago, when the relay heater burned up the terminal mounting.
No relay. It runs as a PSC compressor, like air conditioners. Most refrigerators now have a run capacitor, it shaves about an amp off the run current. It sounds a bit different on startup, instead of "Clickwhirr" , it's more of a soft start "Click-whirr", with about 1/4 second between the sound of the control closing and the motor at speed. With the compression release, it restarts immediately and repeatedly. Amp draw falls below 2 amps when the box is at about 32F (1/6 Hp motor).
And as mentioned above, I put on a 3-wire cord with grounded plug, while I was at it.
I'm sure there's the feeling that I should keep it original, but that ship has sailed. Sailed, made port, and offloaded it's cargo, when the float valve decided it would make a better tubing stopper than orifice. The TXV, receiver and 134a are nowhere near original, but keeping a great machine going for it's original purpose suits me better than preserving a museum piece.
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