Kollmorgen
SERVOSTAR Help
SERVOSTAR
®
S/CD Product Family
41
TROUBLESHOOTING LIST
Symptom Likely
Cause
Motor Runs Uncontrolled
1.) Incorrect phasing on armature or tachometer
2.) Broken or missing tachometer connection
3.) Bad tachometer
4.) Improper compensation components
Motor turns in wrong direction
1.) Improper command phasing
2.) Both Armature and tachometer are reverse-phased
Motor does not obtain desired speed
1.) Insufficient bus voltage to drive motor
2.) Incorrect tachometer scaling
Enable LED does not come on
1.) Missing logic voltage supply
2.) RED Fault LED is indicating a fault condition
Under Volts fault occurs while running
1.) Bus voltage source sags during acceleration
Motor lags in position loop
1.) Insufficient DC Gain
Motor Overshoots
1.) Insufficient DC Gain
2.) Too much AC Gain
Motor drifts slowly
1.) DC Offset in system (Balance pot)
System Stability seems sensitive to load
changes
1.) Adjust Stability pot for less bandwidth
2.) Reduce lead network effect.
Position loop pulls motor into a slightly
incorrect position
1.) Adjust balance pot.
System peak currents are erratic
1.) Worn tachometer causing intermittent signal loss.
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