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Atlas Motor

Greg B

Hot Rolled
Joined
Jul 13, 2002
Location
Irvine, CA
Help! I have an old Atlas 1/2 HP capacitor start motor, catalog #2530A-1. I'm trying to see if I can make run. When I power it up, it just buzzes.
I know that it has some sort of centrifugal switch inside, I don't know if there is a problem with this switch or if I should look at another part of the motor. When I connect a continuity tester to the four wires coming out of the motor, I get continuity between each and all of them. Is this right? Also, can I use electric motor cleaner, or will that eat the fabric insulation on the wires?
Like I said, this is an old motor.
Thanks, Greg B.
 
There are two windings in a single phase induction motor. The first winding is the run winding, which continually energizes the motor. The second winding is the starter winding which as you noted is for a motor this size, contacted in series with a centrifugal switch. May also be one or two capacitors (lobes on the side of the motor). This is where things get a little complicated. If there's just one capacitor (starter capacitor), it will usually be in series with the starter winding. If there's a second capacitor (run capacitor), then this will will be in parallel with the centrifugal switch. The second capacitor provide improved torque characteristic of the motor.

If the 4 leads all show some resistance, then this is good. It means that the windings are not open circuit. I suspect that if the motor just buzzes, then the the starter capacitor is probably faulty. Considering that this is an old motor, I would replace both of the capacitors (provided there are two) to ensure a reliable and good performance.

Albert
 
Thanks for the info. There is only one capacitor, and if I pull the cap off, between the two terminals where the leads are soldered on, the is also a small diode? capacitor? rectifer? I'm not sure what to call it, soldered to the terminals as well. This has colored stripes: green, black, red, silver, brown. The start capacitor itself is a Mallory (big sucker, too, compared to more modern motors). I'll take the numbers off of that to the local motor repair shop to see if I can get a replacement.
Thanks again, Greg B.
 
Greg,

That small component is likely a bleeder resistor, which drains the charge off the capacitor after it is pulled out of the circuit and also prevents arcing of the switch contacts.

If that motor is VERY old, you probably have a BIG paper wound start cap, which were used before the electrolytic type had been invented. If you know the mfd rating of that cap, you can likely find a replacement in the Grainger catalog for under $15.

You'll probably have that motor running very soon!
 
and make sure the contacts on the switch are clean.

try spinning the shaft under power and see if it takes off. this indicates it's the starter circuit that is not working. I agree with the above that because of its age to start with the cap. But as I said, it wouldn't hurt to check out the contacts and see if they are all pitted or corroded or both. A point file (or fine emery paper) could get you started in a pinch until the new contacts arrived.
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If you look at the side of the capacitor case, there should be a rating printed on.

If you don't mind, please post what that value is. Ther will be a microfarad rating and a voltage. The microfarad rating may be a range, like 88-108 MFD, or some such.

I have one of those motors also, but the capacitor value was right where the case cracked open when it failed. That made it unreadable, due to the leaking goo washing off the printing.

I could guess and try, but the real number is always best if you can get it.

Thanks
Jerrold
 
Success!!!!
The motor runs!!!
I filed the contact, good thing I had the wherewithall to pick up that ignition points file at the swapmeet about two years ago, and I could actually find the thing when I needed it. But, the motor does something weird, turn it on, it spins, turn it off, it stops. Turn it on again, spins the opposite direction. And so on and so forth. Now, I still need to pick up a new capacitor to replace the old one, so hopefully that will solve the problem. But I might have the power coming in wired wrong, the leads on the motor are so old, that I can't tell their color. I just guessed, stood back and flipped the switch, but since the smoke stayed in, I think I got that part right.
Anyway , thanks a million to everyone who offered suggestions. They helped tremendously.
By the way, does anyone know what color the old Atlas motors were painted? This one has about three or four different layers of paint. Looks like one might have been a wrinkle finish. I'd like to make the motor look as original as I can.
Again, thank you everyone.
Greg B.

Jerrold, the capacitor says:
MALLORY
A/C MOTOR STARTING
CAPACITOR
(can't make out the patent numbers)
MADE IN USA
CAP MFDS 341-412
A/C VOLTS 110
94728DE

My local motor repair shop said they didn't have an actual Mallory, but another manufacturer with the same rating.
Greg B.

[This message has been edited by Greg B (edited 03-05-2003).]

[This message has been edited by Greg B (edited 03-05-2003).]
 
Thanks for cap value.

I think the original color is black. I have one 1/2 horse that is black and a 1/3 horse that has many coats, bottom one seems black.

[This message has been edited by J Tiers (edited 03-05-2003).]
 
I just acquired an Atlas lathe that has the same motor and it also starts running either direction without changing any wiring. What did you do to correct this problem? I plug it in and it goes counter clockwise, unplug and let it stop, then plug in and it sometimes goes clockwise. This is not good for a lathe to do!
 
I would like to know if anyone has found a starting capacitor that is the same form size as the original Mallory 341 MFD that is currently on my Atlas 2530A-1 electeic motor. It needs to be 2" in diameter and about 3 5/8" long round.
 
As a help to anyone else who comes across this post; I had the same exact issue with the same exact 2530A Atlas motor (inconsistent starting, inconsistent rotational direction once spinning). My issue was the centrifugal switch -- with the motor assembled the switch contacts were not being closed as they should be. I had to shim the non-rotating half of the switch (make sure your clean and test the contact closure fit too!) AWAY from the end bell housing (i.e. towards the rotor and coils). Then I was able to reassemble and confirm with the multimeter that the contacts were closed in an unpowered state. Then, once I applied power to the motor I was also able to confirm the contacts opened as they should once the weights are thrown out to their extended position.

Hope that helps someone; I always hate finding my exact question being asked and then finding no answer...!
 
I would like to know if anyone has found a starting capacitor that is the same form size as the original Mallory 341 MFD that is currently on my Atlas 2530A-1 electeic motor. It needs to be 2" in diameter and about 3 5/8" long round.

Five years later...!

Any ~340 mfd 120V cap will do the trick. The $14 one I got from Amazon is physically much smaller in form factor, but that's not an issue, honestly.

https://www.amazon.com/gp/product/B00EQH2TQG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
 








 
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