User guide
CME 2 User Guide Motor Phasing
Copley Controls 109
10.5: Troubleshoot Manual Phase w/ Encoder and Halls
To perform trapezoidal commutation after power-up or reset, the amplifier must receive
good Hall signals. After the first Hall transition is detected, then sinusoidal commutation
can be performed. In sinusoidal commutation, the amplifier uses the encoder for
commutation while monitoring the Halls to verify proper phase. If the error between the
encoder count and Hall transition is too large, then the Hall phase correction will not be
performed and a phase fault will be triggered.
Test for phase fault problems in the order shown below.
1
Data accuracy test
Verify the motor’s pole count:
Apply a current vector at zero Increment Rate to lock motor in position.
Turn the motor shaft and count the number of distinct locking positions.
Calculate the number of poles: Poles = number of locking positions * 2
Verify the encoder line count OR a linear motor's magnetic pair length and the
encoder resolution.
2
Encoder wiring test
If the Halls produce good trapezoidal commutation but a phase fault is persistent
in sinusoidal commutation mode, the encoder is highly suspect. Try this:
Verify the differential encoder signals.
Verify proper twisted shielded cable with good grounding.
Disable the amplifier and move the motor manually to test for phase fault.
If phase fault only occurs under command of current, make sure the motor
power cable is not bundled with the encoder cable.
3
Hall signals test
If you suspect the Halls signals are faulty, try this:
Make sure Halls change states as the motor moves through one electrical
cycle.
Some Hall signals are noisy and require filtering. Check with motor
manufacturer.
Some Halls are not properly calibrated to the motor manufacturer’s
specification.
4
Hall transition test
If you suspect that the location of the Hall transition is not within +/-30 degrees, try
this:
Adjust Hall offset in smaller increments.
Verify Hall alignment.
Make sure motion is smooth.