Install guide

ARMY TM 5-6675-308-34
MARINE
(6)
(7)
(8)
(9)
(l0)
(11)
CORPS TM 08837A-34/2
Start removing one at a time, until short is
removed, the power inverter assembly A6,
28V converter-regulator circuit card assembly
A3, + 17V converter-regulator circuit card
assembly Al, + 20V converter-regulator cir-
cuit card assembly A2, and sequence monitor
circuit card assembly A5, Monitor standoff
terminals El and E2 until short disappears.
Reinstall all circuit card assemblies except one
which is determined to have caused short and
verify that no other shorts exist.
Replace suspected malfunctioning circuit card
assembly.
If short between standoff terminals El and E2
still exits’ with disconnection of filter circuit
card assembly A4, disconnect standoff terminal
El and see if short is removed from between
standoff terminals El and E2.
If short remains, replace filter circuit card
assembly A4.
If short is removed, check diode CR5 and the
output filter circuit card assembly A9.
f. PS Troubleshootfng Subroutine No. 3- Relay
Check. This subroutine checks
the function of relay K1.
Relay K1 is the main system on-off relay. It connects the
+ 24V input power from either vehicle or the backup
battery, or both, to the power bus leading to the
regulators and inverters. Coil K1-X2 is connected to the
+ 24V power by diodes on the battery charger circuit
card assembly A7, The other side of coil K1-X1 is
connected to ground to energize the relay by the se-
quence monitor circuit card assembly A5. Perform
subroutine no. 3 as follows:
(1) Set BATTERY and VEHICLE circuit breakers
CB1 and CB2 to OFF.
(2) Remove lead from standoff terminal E1 (on
filter circuit card assembly A4).
(3) Check from lead to ground for O VDC.
(4) Set BATTERY and VEHICLE circuit breakers
CB1 and CB2 to ON.
(5) Ground relay K1-XL
(6) Voltage between lead removed from terminal
El and ground should be +23 to + 29V.
(7) If less than + 23V, check diode CR5 for short.
If not shorted, replace relay K1.
(8) Reinstall lead on standoff terminal El.
g. PS Troubleshooting Subroutine No. 4 - A UX
+24V and +12V and +12V Check. This subroutine checks the
functioning of the internal voltages AUX +24V and the
+ 12V. The power supply generates for internal use the
two voltages called AUX + 24V, and + 12V. The AUX
+ 24V starts at A7-J-11 and is called main relay coil
4-122
high, This point is supplied by a diode from either the
vehicle power or the backup power. This means that
AUX + 24V will exist if only one of the power sources
is available. The AUX + 24V is protected from vehicle
voltage transients to 50 volts. This protected AUX
+ 24V is sent to the computer power supply on 3J5-5
and is used to drive relay K1. The + 12V is generated
from the AUX + 24V to turn the system on. The + 12V
is used on 28V converter-regulator circuit card assem-
bly A3 to power the switching regulator circuits until
the + and –14V is available. The + 12V is also used
on the sequence monitor circuit card assembly A5.
Perform
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(l0)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
subroutine no. 4 as follows:
Measure AUX + 24V at relay K1-X2.
If AUX + 24V is not present, set BATTERY
and VEHICLE circuit breakers CB1 and CB2
to OFF.
Set PSTS INPUT POWER UUT circuit
breaker to OFF.
Set INPUT POWER PSTS circuit breaker to
OFF.
Set O to + 40V input power source to off.
Replace battery charger circuit card assembly
A7.
Set PSTS INPUT POWER PSTS circuit
breaker to ON.
Set INPUT POWER UUT circuit breaker to
ON.
Set O to + 40V input power source to on.
Set BATTERY and VEHICLE circuit breakers
CB1 and CB2 to ON.
Check for + 12V at sequence monitor circuit
card assembly A5 connector P2-1.
If + 12V is not present, the fault is in one of
three assemblies; 28V converter-regulator cir-
cuit card assembly A3, sequence monitor cir-
cuit card assembly A5, or battery charger
circuit card assembly A7.
Set BATTERY and VEHICLE circuit breakers
CB1 and CB2 to OFF.
Set PSTS INPUT POWER UUT circuit
breaker to OFF.
Set INPUT POWER PSTS circuit breaker to
OFF.
Set O to + 40V input power source to off.
Remove 28V converter-regulator circuit card
assembly A3.
Set PSTS INPUT POWER PSTS circuit
breaker to ON.