HindlePower AT30 SERIES Operating And Service Instructions page 56

SERVICING THE AT30
PROBABLE
SYMPTOM
CAUSE
DC breaker 1. Battery
(CB2) trips connected with
immediately
reverse polarity
2. Defective
rectifier bridge
(if AT30 is
UN-unfiltered)
3. Defective
free-wheeling
diode
4. Defective
polarity diode, if
dc filter
assembly is
installed
5. Defective
wiring
DC breaker 1. Loose
(CB2) trips connection to
after a few breaker
minutes
2. Open SCR
3. SCR not
controllable
4. Defective
Gate Driver PC
Board (A15)
5. Defective
Main Control PC
Board (A1)
50
RECOMMENDED ACTION
1. Check battery wiring. Correct if necessary.
2. Test by disconnecting wires # 7, # 8 & # 9 at the rectifier
modules (A16x) or at the transformer (T1-X#). Measure
resistance between the ac input terminals on the rectifier. Check
both polarities. It should be at least 100,000
low in either direction, replace SCR modules (A16x) as needed.
3. Locate the free-wheeling diode (CR4), which is mounted on the
negative (-) bus bar of the three-phase rectifier heat sink
assembly (A16). Disconnect the "flag" (wire # 15) of the diode at
the positive (+) bus bar. Measure resistance through the diode
(CR4). Check both polarities. It should be at least 100,000
one polarity, and less than 1,000
defective, replace the free-wheeling diode (CR4).
4. Disconnect wire # 17 from the dc breaker (CB2). Measure the
resistance through the polarity diode (CR1) mounted to the neg(-)
filter cap bus bar. Check both polarities. It should be at least
Ω
100,000 in one polarity, and less than 1,000
polarity. If it is defective, replace the polarity diode (CR1).
5. Check spacing of terminals. Check wiring for signs of
insulation damage, burns, etc. Repair as necessary.
1. Check connections to the dc output circuit breaker (CB2)
and/or optional dc output fuses (F3/F4). Tighten as required.
2. Use a clamp-on ammeter to measure current in wires # 7, # 8,
and # 9, between the main transformer (T1) and SCR modules
(A16x). If it less than 50% of the dc output current, one of the
SCRs is defective. Replace rectifier modules (A16x) as needed.
3. Disconnect the wire harness plug from connector J26 on the
top of the Gate Driver PC Board (A15). Restart the AT30. If you
are able to measure dc output current, one of the SCRs is
defective. Replace rectifier modules (A16x) as needed.
4. If the front panel meter displays more than 110% of the AT30's
rated dc output current, the Gate Driver PC Board (A15) may be
defective. Unplug A15 from the Main Control PC Board (A1). If
the output current does not drop to zero, replace the Gate Driver
PC Board (A15).
5. If the front panel meter displays more than 110% of rated dc
current, the control board may be defective. Unplug the system
harness connectors (J25 and J26) from the Gate Driver PC Board
(A15). If the output current drops to zero, replace the Main
Control PC Board (A1).
Ω
. If resistance is
Ω
in the other polarity. If it is
Ω
in the other
Ω
in