Troubleshooting
table
Problem (and system
status numbers)
Possible cause
Action
System status display not
lit.
No control power.
Check that SC955 has AC
switch set to INT or
SC952, SC953 and SC954,
have 115 V ac or 230 V ac
applied to J3 pins 5,6.
Blown control power fuse.
Replacement of fuses
within the drive is not
recommended and rarely
useful. A blown fuse is a
strong indication that the
drive is defective and
should be returned to the
factory for repair.
Controller unconfigured
(U/C).
New controller.
Perform controller setup.
Resolver conversion
overspeed (1).
Incorrect resolver phasing.
Verify proper phasing.
Open or intermittent
resolver connection.
Check connector and cable.
Motor overtemperature (2).
Motor PTC pins open.
Connect PTC pins (J3-8
and J3-9).
Temperature overload due
to high motor ambient
temperature or excessive
RMS torque.
Lower ambient
temperature. Operate
within continuous torque
rating.
Motor PTC damaged.
Check motor PTC for
resistance
≤
310 ohm.
MA950
5 - 5
