Troubleshooting During Power-Up
1-7
The AC input box accepts three-phase power; the three leftmost indicators
on the circuit breaker show the state of each pole (one phase per pole). If
an indicator is green, the pole is in the Off position or tripped due to an
overload. If an indicator is red, the pole is in the On position and is not
tripped. The fourth rightmost indicator reflects the mechanical position of
the circuit breaker. This indicator is red when the circuit breaker is in the
On position and green when the circuit breaker is in the Off position.
Figure 1-4 shows the troubleshooting steps for the AC input box.
Figure 1-4
AC Input Box Troubleshooting Steps
System or
Expander
Rear
Circuit Breaker
Indicators
are Red
No
Check power regulators for an input short.
BXB-0075A-92
Disengage power regulator and set circuit
breaker to the ON position.
If green indicator appears again,
AC inputbox is bad.
Remove & insert power regulator in another slot.
Set circuit breaker to the ON position.
If green indicator lights indicating the new slot is bad,
replace the power regulator.
C
B
A
S
For more information:
Platform Service Manual