GE SPM Series, Instruction Manual

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7-
6
SPM Synchronous Motor Protection & Control GE Power Management
7.4 TROUBLESHOOTING 7 TESTING AND TROUBLESHOOTING
7
7.4 TROUBLESHOOTING 7.4.1 TROUBLESHOOTING GUIDE
Table 7–1: SPM TROUBLESHOOTING (Sheet 1 of 2)
SYMPTOM POSSIBLE CAUSE CORRECTIVE ACTION
The SPM READY
message is not
displayed at
power-up (motor
not running). Control voltage missing. Check control fuses in synchronous controller (on primary and
secondary of control power secondary).
Connection plug is missing. Insert connection plug at bottom of cradle assembly (see
Figure....)
Drawout cradle not fully
engaged Check removable cradle assembly and confirm that the top and
bottom rotating latches engage cradle and are positioned to
engage connection to disconnecting sockets at rear of case.
Wrong voltage is applied to the
V
1
and V
2
terminals.
Control voltage must be in the range of 85 to 265 V AC.
Display is frozen. Drop control power momentarily to the SPM and reapply. Some
portion of the display should be actively blinking. If not, the CPU is
not functioning. Replace with a new SPM.
Missing or improper motor-on,
motor-off input to SPM Add or correct the isolated normally closed interlock from the main
contactor or relay operated with the main contactor. Interlock is to
be placed across MX to MX1 interlocks.
NOTE: This interlock must be open when the motor is engaged.
SPM not properly programmed. Call each program address and check setpoint data against the
desired setpoints (usually listed in the controller elementary).
If the exciter voltage option is
supplied, exciter may not be
energized Correct the operation of the DC field exciter so it outputs DC.
Relay in tripped condition. Press any keyboard button to RESET.
Internal connector cable loose. Remove front panel and check ribbon connectors for tightness.
Ensure connectors are not skewed or partially connected to pins.
Wiring to terminal points on
rear of unit are missing / loose. Connect or tighten missing/loose wires to proper points on the
rear of the unit.
Motor starts but
will not
synchronize (FC
does not close) Synchronizing slip set too low.
Motor cannot accelerate to slip
level. Refer to the setpoint programming instructions (Chapter 5) and
program a higher value of percent slip.
FAR relay does not pick up
(SPM flashes
FIELD IS APPLIED
but contactor does not close).
Check external FAR contact circuit wiring.
Field discharge resistor
(sometimes shipped
separately) is not connected or
incorrectly installed Check the connection of the field discharge resistor and correct if
necessary.
Motor trying to accelerate
excessive load Unload or reduce load on motor shaft until FCX relay picks up.
A motor restart is aborted by
SCP operation (
SQL CAGE TRIP
displayed)
The motor is taking too long to start or the stall time or run time
setpoint is set too low. Correct as necessary
Wiring to terminal points are
missing or loose. Connect or tighten missing or loose wires to proper points on the
rear of the SPM.