Machine - Okuma MX-45VAE

Problem - When running the spindle at or more than 1148 rpm (high gear) and M05 command is given to stop the spindle, an alarm 4053 or 1051 will show on the screen and either 13 or 34 code on the VAC drive itself.

Tests preformed - Tightened all power and ground contact points from breaker panel to spindle motor, Checked for voltage spike across R S T legs of VAC drive, checked all terminals on Top Board of VAC drive when in resting state, inspected wires/cables for burns or cuts, checked all glass fuses, measured resistance between terminals on the IGBT modules.

Abnormal Findings - The two terminals in the Regeneration Control Circuit which in my book (Maintenance Manual 4th Edition Pub.No.3727-E-R3 (SE34-001-R4) June 1995) says should be +6 VDC and COM. When putting my meter to these terminals I am getting 15.47 VDC. One question is - Has the design of the Top Board been changed since the 1995 publication or is that one of my problems.

Conclusion - When I removed the VAC drive from the machine and removed the Top Board and Power Board no physical damage could be seen.