Rockwell Automation LZ Series Linear Motors - Manual (Page 23)

Publication LZ-UM001A-EN-P - January 2008
Troubleshooting 23
Motor Coil Electrical Test Perform this test after installation and when a coil electrical fault is suspected.
1. Ensure the coil is at room temperature, approximately 25 o C (77 o F).
2. Turn the drive power OFF.
3. Ensure all the motor leads (phases and ground) are disconnected from
the drive.
4. Referring to the diagram, measure the phase to phase (p-p) resistance of
the three phase combinations and record the values. The three readings
should be approximately equal to each other.
5. Measure the phase to ground resistance for each phase.
The resistance to ground should be in excess of 100 megohms. A lower
reading may indicate an electrical problem.
6. Disconnect the field cable at the coil assembly interface and repeat
procedure.
If any reading is still below 100 megohms, consult Anorad, as the motor
may have an internal electrical problem.
ATTENTION
Dangerous voltages, forces and energy levels exist in servo
controlled systems. Extreme care must be exercised when
operating, maintaining or servicing the linear motor to prevent
harm to personnel or equipment
Lamination
Frame
R
p-n
R
p-p
U
V
W
Motor Phases
Motor Ground
Shield
R
p-p
= R
p-n
X 2