Haas Axis Servo Motors
Haas machines on the Next Generation Control run Sigma-5 or Sigma-7 axis servo motors. Each motor runs on its own servo amplifier and sends encoder data back to the control. Alarm 217 AXIS PHASING ERROR can mean the wrong type of motor went in or the cables are connected wrong.
Haas Servo Motor Repair Shops
ACS Industrial Services
Cockeysville, MD
Brands: Fanuc, Haas
Alarms That Point to the Motor
Alarm 645 AXIS AMPLIFIER GROUND FAULT and alarm 993 AXIS SHORT CIRCUIT point to a faulty power cable or a faulty servo motor. Encoder fault alarms such as 9719 trace to noise from high power cables or a faulty servo motor encoder. Haas calls for a check of the servo motor for coolant intrusion with those encoder faults.
Alarm 103 AXIS SERVO ERROR TOO LARGE has more possible causes than the motor itself. Encoder noise, a motor brake that does not disengage, and a damaged ballscrew all appear on the Haas list. A faulty power cable or a ballscrew coupling knocked out of alignment in a crash can trigger the same alarm.
Testing the Motor and Its Cable
The power cable comes off at the motor side for an inspection of the connectors. Coolant contamination at those connectors can generate drive fault alarms and damage the amplifier.
A meter on resistance from pins A, B, and C of the motor connector to chassis ground should read an open circuit. Any other reading means the motor is at fault. A continuity test from the ground pin to chassis ground should read under 1 ohm. Resistance between pins A, B, and C then gets compared with the winding values in the Haas table for that motor.