GE GEK-113045B Manual page 77

7 TESTING AND TROUBLESHOOTING
Table 7–1: SPM TROUBLESHOOTING (Sheet 2 of 2)
SYMPTOM POSSIBLE CAUSE
Motor starts and TRIP PF setting too high.
synchronizes but
FCX DELAY setting too low.
shuts down
immediately upon
Current/voltage inputs are
application of
incorrectly wired or are from
excitation.
incorrect phases.
No excitation voltage.
No excitation current, open
circuit at motor field, brushes,
or leads.
Wiring to terminal points is
missing or loose.
Shutdown occurs Motor has pulled out of step
during normal from excessive overload (PF
running (after TRIP or PULL-OUT TRIP is
successful displayed)
synchronization)
Loss of excitation
Transient power factor change
occurring during system power
disturbance.
Motor is unloaded and power
factor regulator reference
setpoint at or near unity
resulting in instability.
Wiring to terminal points on
rear of unit missing or loose.
Motor starts, Exciter voltage too low causing
applies DC to SPM to attempt
field and then resynchronization.
immediately
Field contactor closing too
removes DC from
soon. Motor cannot pull-in to
field
step since slip too high.
Excessive shaft load greater
than the motor's capability to
pull into step.
Wiring to terminal points on
rear of unit missing or loose.
Display frozen, Loose electrical connections or
garbled, incorrect, CPU failure.
or unreadable
Contrast needs adjustment.
GE Multilin
Courtesy of store.ips.us
CORRECTIVE ACTION
Reduce TRIP PF value (address 01) to no higher than –0.8.
Increase FCX DELAY setting to 3 seconds minimum.
Check and correct wiring as required.
Check for available DC excitation voltage. If a rotating exciter
driven by a motor shaft is used, the exciter field should be forced
(rheo is shorted out) during acceleration to cause exciter to build
up its output as quickly as possible.
Correct discontinuity in field circuit.
Connect or tighten missing or loose wires to proper points on the
rear of the unit.
Check condition of load bearing and other mechanical situations
at drives. Push any key to reset the SPM and restart.
Check exciter, exciter fuse, and connections to field.
Increase PF DELAY setting.
Increase REG FLOOR setpoint to override regulator to maintain
stability during light-load condition.
Connect or tighten missing or loose wires to proper terminal
points on rear of unit.
Adjust exciter transformer tap or exciter adjustment potentiometer
to obtain higher exciter voltage output.
Reset SYNC SLIP to lower value.
Reduce load or unload motor during start. Apply load after motor
has synchronized and stabilized.
Connect or tighten missing or loose wires to proper terminal
points on rear of unit.
Momentarily interrupt control power to unit and then re-energize. If
still displaying incorrectly, replace unit OR check ribbon connector
between faceplate assemble and top of cradle. It must not be
loose, shifted, or skewed.
Open lower flip door on faceplate assembly and rotate the
contrast adjustment to obtain clear display.
SPM Synchronous Motor Protection and Control
7.4 TROUBLESHOOTING
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