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Installation www.emersonct.com 5
2.6 Simple Servo Motor Phasing
Test
When connecting a non-standard servo motor to the
Unidrive SP, it is necessary to know the wiring
configuration of the motor. At times, all of the necessary
wiring documentation for connecting the motor is not
readily available from the motor manufacturer. In that case,
it may be possible to follow the simple servo motor phasing
test described below. This will help to determine if the
motor phases (U, V, and W) are wired correctly along with
the encoder commutation and channel signals. If the
procedure described below is followed, and you still have
problems, please refer to the Unidrive SP User Guide for
further wiring information.
Begin by entering the motor peak current, continuous
current, number of poles, encoder lines per rev., etc. Then
follow the steps below.
Step 1: Verify wiring of encoder channels per the
documentation. Define CW rotation of the motor
shaft, from the flange side, with increasing counts.
To verify this, do the following
A Disable the drive
B Navigate the keypad to display parameter # 3.29
C Turn the shaft clockwise and verify that the encoder
counts increase from 0 to 65535
D If the counts decrease, the encoder A and B channels
should be swapped
E Repeat A through C of Step 1
Step 6: Verify wiring of motor power cables. Define
CW rotation of the motor with a positive drive
command. The phasing test of the Unidrive will
give a CW rotation during the test.
To verify this, complete the following steps:
A Enable the drive.
B Verify that the motor is free of any load.
C Navigate the keypad to display parameter #0.40.
D Set the parameter to 1. The phasing test will
command the motor to move one rev CW. It will also
reset the parameter to 0.
E If the motor moves in the CCW direction, the motor
power is wired incorrectly.
F Swap the U and V phases and repeat A through D of
Step 2.
Note
Disregard any encoder phasing trip at this time
[tunEx trips]
Step 7: Verify wiring of commutation signals. The
Unidrive SP Advanced User Guide section 3
(parameter 3.25) is helpful for this step.
If no trips were encountered during Step 2, this step can be
skipped.
To verify correct commutation, follow the steps below:
A Enable the drive.
B Navigate the keypad to display parameter #0.40 and
set the parameter to 1.
C If an tunE3 or other tunEx trip results, rewiring is
needed.
D Swap the U and V commutation signals at the drive
end.
Repeat steps A through C to verify.