
Originally Posted by
maver1ck
Find out where you are losing the 24VDC signal which tells the control the spindle is at speed. There were some variations based on the vintage of the machine, so be sure to check your prints and not just assume the numbers I'm giving here are accurate.
The basic way this signal works is when the spindle motor reaches the programmed speed, the drive outputs a signal indicating it is at speed. This output from the drive closes CR13, and the output wire from CR13 brings the spindle at speed signal to the control on Input 24 after going through 1 or more plugs (depending on vintage).
You should look at your prints to verify the points where you can check for voltage, but CR13 should be pretty easy for you to find and determine if the contacts are closing properly and if you are getting the 24VDC into and out of the contactor.
Based on what you find at CR13, you should be able to determine if you need to replace the relay, or if the problem is in front of or after the relay so you know where to look next.