Publication 2364F-5.05 - March 1999
2-2
Troubleshooting The RGU
Unit Will Not Start
After the disconnect lever and start switch have been turned on, the RGU
should power any connected HIM or GPT devices and perform its
precharge routine to raise the voltage of the capacitors on the DC bus.
Check the following items if the unit will not operate.
Is power available to the unit?
Are the AC line fuses in good condition?
Replace
all
the AC line fuses.
Are the primary fuses (F4, F6) in good
condition?
Replace
both
of
the primary fuses.
Is the control power fuse (F7) in good
condition?
Replace the control power fuse.
Are the precharge fuses (F2, F4) in good
condition?
(F9, F10 for J-code RGU)
Replace
both
of the precharge fuses.
Test the precharge resistors (as instructed
in Chapter 4). Are the precharge resistors
at their rated resistance?
Replace the damaged precharge resistors.
Test the IGBTs (as instructed in Chapter 4).
Are any of the IGBTs damaged?
Replace the damaged IGBTs. Test and
replace the gate driver board and snubber
boards as necessary.
Are the DC bus fuse(s) in good condition?
Replace the damaged bus fuses.
Make power available to the unit.
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
Yes
No
No
Yes
Test the main control board, isolation board,
and gate driver board (see Chapter 4).
Replace any damaged boards.
Push the disconnect lever to off and verify zero volts
across the DC bus before testing the following items.
!
ATTENTION:
