Rockwell Automation MV SMC Flex Motor Controller (for Series K or later) - Manual (Page 76)

66 Rockwell Automation Publication 1560E-UM051F-EN-P - June 2013
Chapter 3 Commissioning Procedure
Figure 40 - Gate Pulse Detail – Typical SCR (ABB)
Figure 41 - Gate Pulse Test Waveform
10. If no pulse is observed, and the yellow LED is lit, check for a shorted gate
on the SCR by removing the green plug and connecting an ohmmeter to
the gate leads. If the LED is not lit, and the circuit voltage is as specified in
step 8 (above), pinch the tab on the blue fiber-optic connector and
carefully pull it straight out of the receiver. The end of the connector
should glow red to indicate the presence of a gate signal.
If it does not, remove the other end of the cable from the interface board
and check that the gray transmitter is emitting red light. If it is, the
fiber-optic cable must be replaced. If it isn’t, the interface board should be
replaced.
11. When each gate driver circuit has been checked, disconnect the power
supply and remove it from the cabinet.
ATTENTION: The gate-drive circuits operate at high voltage when the SMC is
energized. Failure to remove the portable test power supply will result in
equipment damage and may cause severe injury or death.
Microseconds
Vo
lts
-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 - - - -
Milliseconds