Control Data Corporation CYBER 180 810 Maintenance And Parts Manual page 157

SAM 2 - AC TO DC CONVERTER INPUT CIRCUIT BREAKER TRIPPED
Assumptions: 1) PRESS RESET indicatior is on. 2) CB OFF indicator is on.
3) AC to DC CONVERTER INPUT circuit breaker has tripped.
0010 N
Y
0020
0030
0040
0050
0060
0070
0080
0090
0100
0110
0120
0130
1
2
3
'
-
1
2
N
y
1
'
-
1
2
3
4
N
2
A
y
Are any of the following fault indicators on? HIGH TEMP AIR IN,
LOW AIR FLOW, LOGIC POWER SUPPLY, CABLE PROTECTION or HIGH TEMP AIR
OUT.
This is a back-up shut down condition, these faults normally
disable the logic power via the primary protection circuit without
tripping the AC TO DC CONVERTER INPUT cb.
Refer to SAM 3.
After the fault has been corrected, determine why the primary
protection circuit did not shut the power down without tripping the
circuit breaker. Use diagrams and meter.
Remove the ac to de converter from the circuit by unplugging the
3-contact connector from Jl of the ac to de converter.
Attempt to power on (reset and on).
Does the AC TO DC CONVERTER INPUT cb trip?
The problem is either in the circuit breaker or the wiring.
It will be necessary to troubleshoot using the diagrams and a
voltmeter. Use caution when working in this area.
Reconnect the 3-contact connector to Jl of the ac to de converter.
Unplug the 2-contact connector from
Jl
of the capacitor bank ass'y.
Unplug the 2-contact connector from J4 of the ac to de converter.
Attempt to power on (reset and on).
Does the AC TO DC CONVERTER INPUT cb trip or is there smoke coming
from the ac to de converter?
WARNING
Be careful when working with the capacitor
bank. There can be up to 300 V de
between pins 1 and 2 OF Jl.
60469500 A
C-5