Rockwell Automation 20G PowerFlex SCR Bus Supply - Manual (Page 41)

Start Up/Troubleshooting 2-7
PowerFlex SCR Bus Supply User Manual
Publication 20S-UM001G-EN-P
Important: Complete the tests listed in Table 2.C without power applied to
the SCR Bus Supply.
Table 2.C Control Terminal Block Continuity Test Conditions
Test Condition Possible Cause Corrective Action
N.C. contact on
control terminals
6 and 7 is open 400A and 600A Unit: Open
snubber fuse (F6…F8).
1000A Unit: Open snubber
fuse or open DC bus fuse
(F7…F11).
1. Check for evidence of power module failure (see
Step 3 in Start-Up on page 2-2 ).
2. Check for evidence of failure in snubber circuit.
Check the snubber pcb diodes and snubber
resistor and capacitor.
3. Replace entire SCR Bus Supply if any device
has failed.
4. If there is no evidence of a failure, check for open
fuse and replace.
N.C. contact on
control terminals
8 and 9 is open 400A and 600A Unit: Open
AC line fuse or open DC bus
fuse (F1…F5).
1000A Unit: Open AC line
fuse (F1…F6).
1. Check for evidence of power module failure (see
Step 3 in Start-Up on page 2-2 ).
2. Replace entire SCR Bus Supply if any device
has failed.
3. If there is no evidence of power module failure,
check for open fuse and replace.
N.C. contact on
control terminals
10 and 11 is open Open heat sink
Overtemperature Switch 1. Verify that maximum ambient temperature is not
exceeded.
2. Replace the Overtemperature Switch.