Siemens SIKOSTART 3RW34 Instructions De Service page 70

Troubleshooting
Fault
Motor does not start and LED 1
is not on
Motor does not start and LED 1
is glowing steadily
Motor does not start and both
LEDs come on at RUN
command
Motor starts but does not
come up to speed
Motor growls or hums at start
but comes up to speed
Motor growls at start and does
not come up to speed
Motor comes up to speed too
quickly
Motor runs noisily with very
high current
Motor starts hard,
not softly
Table 15 : Troubleshooting
30
Cause Check/Remedy
No main power Check input side of terminals L1, L2 and L3 for open disconnect switch, breaker
trip, or insecure terminal connections. Verify that proper three-phase incoming
power is present per Section 7.5, steps 3, 4, and 6.
No control power Check input side of control terminals X1 and X2 for blown fuse, any open circuit
condition or insecure terminal connections.
Verify that proper control voltage is present (within +10%,-15% of nominal soft
starter rating). If the control circuit includes a control power transformer (CPT),
verify that the CPT primary voltage is present and proper for the CPT primary tap.
Motor not connected to soft Check that any series disconnect switch or isolating contact is closed. Check for
starter tripped overload relay. Determine and remedy cause of trip per "Motor overload
relay trips..." trouble below.
Verify that the motor is connected to the soft starter. With proper incoming
power and the motor connected but stopped, voltmeter readings across
terminals T1 and T2, T2 and T3, and T3 and T1 should be zero. A reading of line
voltage indicates that the motor is not connected properly.
Discontinuity in the control Check that control power is present at terminals A1 and A2. If power is not
input circuit to the RUN coil present, check for insecure wiring connections at terminals A1 and A2, at
applicable control terminals (13, 14, etc.), and at the control devices (e.g.,
start-stop device, isolation contact) used in the input circuit to the RUN coil.
Bad cable connection or Remove control power and check that Logic PCB-to-Snubber PCB cable is
defective printed circuit secure. If secure, remove main power and replace Logic PCB and/or snubber
board (PCB) PCB.
Faulty motor Troubleshoot motor according to the manufacturer's instructions.
Inside Delta wiring problem See problem 3 in Table 16.
Soft starter not finished Check that LED 2 is on, which indicates output voltage equals line voltage. If
ramping to line voltage motor is coming up to speed too slowly, decrease Start Time T1 and/or increase
Initial Voltage U; refer to Section 7.6.
Initial Voltage U is set too Raise setting of Initial Voltage U until motor just starts to rotate when power is
low first applied; refer to Section 7.6.
Motor unable to start load Check load for mechanical blockage (rocks, logs, seized bearings, etc.) Increase
motor size; for proper soft starter selection, refer to Section 4.
Soft starter not finished Check that LED 2 is on, which indicates output voltage equals line voltage. If
ramping to line voltage motor is coming up to speed too slowly, decrease Start Time T1 and/or increase
Initial Voltage U; refer to Section 7.6.
Shorted SCR (LED 2 double Check SCRs as described in Section 10.4.
flashing)
Improper settings Adjust Start Time T1 and Initial Voltage U settings per Section 7.6.
Load is too light or too heavy Adjust load or consider decreasing or increasing motor size; for proper soft
starter selection, refer to Section 4.
Inside Delta wiring problem See problem 1 in Table 16.
Improper setup Refer to Section 7.6 for motor starting adjustments.
Shorted SCR Check SCRs as described in Section 10.4.
(LED 2 double flashing)
Inside Delta wiring problem See problem 4 in Table 16.
3ZX1012-0RW34-1AN1