Reid Surface grinder motor wiring

[Josh1]

We have a Reid surface grinder from the 60's. It uses a single phase 220V motor to move the table from left to right. The machine was run out of oil which caused the motor to overheat. The motor was rebuilt, and the machine left in pieces from the previous maintenance tech. 6 years later I get to try and finish repairing it. The surface grinder reverses the motor to change the tables direction. So, every pass under the grinding wheel the motor will reverse. The electronic circuitry has been modified from original. A capacitor of some sort has been added, or maybe it was always installed, I can't tell. It looks like it was added later inside the electrical cabinet. The motor has no centrifugal switch for a start capacitor. It has 6 wires in the motor; 1,2,3,4,5, and 8. The motor tag doesn't show a wiring diagram so I'm assuming (3,8,2), (1,L1), (4,5,L2) and swap 8 & 5 to reverse. How is a capacitor supposed to be wired in if there's no centrifugal switch to turn off the capacitor? This seems like a very strange design. Constantly starting and stopping and starting the motor. Any help is appreciated.

 

[Jim Christie]

Maybe you have already looked on the information on Vintage Machinery

Reid Brothers Co., Inc. - Publication Reprints | VintageMachinery.org

There may be something there about the drive system you have.
I know that some 3phase motors can be made to operate on single phase with starting and running capacitors and one or more relays, so that is perhaps the case with yours since instant or rapid reversing for back-and-forth table movement may not work well with a centrifugal switch.
Since I'm not well versed in electrical work, I'll let some others comment on that.
Some older mechanical feed grinders had a reversing gear box to reverse the table using a mechanical linkage and dog clutches with a neutral position, so the motor ran constantly in only one direction.
Jim

 

[Josh1]

Hi Jim. Thanks for the reply. I've checked out there website and they have the same manuals that I already have and they don't show anything as far as electrical diagrams.
Josh

 

[Jim Christie]

If you can post some pictures of the motor and electronics that you have it might help one of the other members who know about those things to help you out.
You might also post a cross link on the Abrasive Machining section of the forum to this thread in case someone on that section of the forum who doesn't visit this Antique section of the forum may know something as well.

Abrasive Machining

Discuss grinding and abrasive techniques and machines >> moderator eKretz

www.practicalmachinist.com

 

[reggie_obe]

What model Reid grinder is it?
There is one manual on VM that has a wiring diagram for both 2 and 3 phase grinders. Might be similar enough to help figure yours out.