Identify bearings from an old Reliance motor

[Kaustic]

Hi All,

I scanned around to see if this question has been asked, but didn't see it (at least not with the flavor of search terms I used)

I have an old Reliance motor (pre-Baldor-Reliance) and I need to identify the bearings to use condition monitoring. I've looked into the Baldor-Reliance cross reference, but this motor isn't in there. I've attached the tag on it, I have other motors that may have this problem as well, but I didn't want to clog up the forum. As a side note, I always feel bad calling a rep for information when I'm not going to be purchasing anything.

Thanks for your help,

-Josh

 

[dArsonval]

Josh;

The frame number indicates something special about the shaft.

The shaft "U" dimension should still be 3-5/8" in diameter... so the D.E. bearing is going to be
in the neighborhood of 19, or a 20. (6219 or 6220) maybe a 21...
As large as the motor is, I don't believe it has 300 series bearings in it... but this is the Internet.
I could be totally wrong.

The only way to know for certain, is to pop it apart and see what the bearing sizes really are.

Bearing sizes in AC motors have been documented fairly well for decades, but DC machines are
a little more ellusive.

The last two letters on the ID number is the date code. CZ would indicate March, 1974.
It looks like it could be a G instead of a C in which case a GZ indicates July, 1974.
(It seems hard to believe the motor is that old.)

Under the motor Type... the T designates a DC motor but not sure what the additional R means.

Lastly, I don't think a "rep" is going to know the answer.
They're just going to end up having to call the factory.
I'd contact the manufacturer (Product Marketing) directly.
If there ends up being something proprietary about the motor, the manufacturer won't likely
give you the information anyway. So, you may end up having to take it out of service to find your answer.

John

 

[Kaustic]

John,

​

Many thanks for your help. It is indeed a DC motor from before I was born. This machine is certainly at least 50 years old, its mate sits across from it still spinning as well. I believe this motor was rewound once, before I was here. Unfortunately, taking it offline and opening it up isn't feasible, at least not until it breaks.

I may just use a '20 as a baseline and see if my frequencies match up.

Regards,

-Josh

 

[mike gergen]

This motor was built in the early 50s. I think 1953.

There ins't any information on the bearings anymore. Something this old will probably need to have the endbells machined also so your best bet will be to take it apart. The lams should also be tested.

 

[dArsonval]

Mike, just when I was going to give you a purple star for posting the PDF on the Baldor motor in the other thread, I have to peel it back off now ; )

In an effort to be as correct as possible related to the date of manufacture, which has nothing to do with the original question I'll explain further.

The last two letters of the ID number on the plate represent the date code.
The month letter is first, followed by the year letter.

Three charts currently exist to decipher Reliance name plates.
The first published chart covers motors made from 1951 to 1974.

Referring to the name plate posted by Josh, the last letter is a Z denoting 1974.

IF the motor had been built in 1953 as Mike is suggesting, the last letter stamped on the plate would be a "C".

The second published chart represents motors manufactured from 1975 to 1997.
A "Z" on that chart would denote 1997.

On the third chart, a "Z" indicates the year 2020. We know it cannot be that.

I made a guess that the motor is older than 1997, which Josh agreed that it was made before he was born.

One of the main attributes of the name plate that caused me to say it was made in 1974 other
than merely relying upon the last letter, was the style of the plate itself.

If the motor had been made in the 1950s through the '60s, the shape and style of the plate
would be quite different than the plate shown at the beginning of the post.

And of course, had the motor been made before the advent of Reliance's letter code system, the plate
would be of cast design, and not stamped.

Attached photo helps illustrate the above.

The motor nameplate represented by the OP's photo was definitely attached at the factory in 1974.

John