Servo System Trouble Shooting

1
Servo SystemTrouble Shooting
2
General Problem Management

• Problem

NO
NO
Can I handle it, now?
Can I identify the bad device?
YES
YES
Can I restart from the same state where I
stopped?
Call the technician
Change the device
Fix the problem
YES
NO
Eventually wash the machine, and restart from
step 0
Restart immediately
3
Motor

• Not powering on
• Not running
• Run reverse
• Moving not continuously
• Motor temperature alarm as soon as motor is on
• With Jaw System connected the servos cannot keep
  the position when OFF

• Check DC bus low (out 7 SAM-P connector)
• Check the brakes, the brakes wires and relay
• Check U, V, W correspondence on motor side
• Check the winding connector
• Check the resolver connector
• Do NOT just revert the phases order
• Check the overtemperature wires
• Check the brakes
• - Switch OFF the servos (step down)
• - Try, by hand, to move the links and, if
  successful, free the motor shaft and try to move
  it with a dynamometer key it
  is a 50 Nm brake

4
Resolver

• Motor running not correctly (see motor slide)
• Resolver error (Main sensor measure defect)
• The Home Position of the Jaw System seems wrong
• Going to Home Position it is always colliding
  (lag error)

• Check winding and resolver connector/connections
• Check resolver connector and the shielding
• Check impedance between
• cos1 - cos2 and
• sin1 - sin2 and
• ugen1 - ugen2
• they all should be
• Rlt50-100ohm (Clt3-4uF Llt10mH)
• The Referencing Routine has to be performed (the
  axes for some reasons have lost their position
  relative to the mechanical stops)