It's been a while since I updated this thread and boy, there are a lot of updates to catch up on!
A few weeks ago we finally got around to prepping my Quincy 5120 for installation. I need way more air than my little IR compressor can make and this machine will do the trick.
I hadn't run this machine since I bought it and I wasn't sure of it's condition. Hooking it up to power, it wouldn't start!
Delving into things further, I finally decided to remove the drive belts and start the motor unloaded. Upon applying power, the motor accelerated slowly and seemed to be running a lot slower than it should.
Using a coil wound around a bolt and a multimeter with a frequency setting, Xarrax, my partner, and I were able to determine that the motor will only accelerate to exactly 600 RPM. Hmmmm! 1/3rd of synchronous speed... I think a couple of coil groups are backwards!
I double-checked my wiring and it was indeed wired correctly as a low-voltage delta per the lead numbers! Fearing a failed motor, I megged out the windings and everything checked out. Looking more closely, it became apparent that the previous electrician had mis-identified several leads of the motor as several lead numbers didn't correspond to the correct delta groups.
Looking online, I found an excellent method of identifying delta connected motor leads using a 12 volt battery and a meter. I ripped off all the lead numbers and followed the procedure. Here's the Youtube video:
I re-connected everything with the proper lead numbers and it runs!
I decided to give it a once-over and do a valve job while it was easily accessible. This thing has 12 valve cages to do!