Th49-2320-387-24-2
18-3. ILOO-AMPERE
DUAL VOLTAGE ALTERNATOR TESTING AND REPAIR (Cont’d)
NOTE
l When tachometer reaches 3,000 rpm, green lamp should go off
indicating proper charging from alternator.
l Normal voltage range is 26-30 VDC. High amperage is +lO percent
over the rated alternator output of 182 amps at 5,000 rpm.
10.
Perform no-load test. Increase alternator speed to 5,000 rpm; record results. Refer to table 18-1 for
diagnosis.
11.
Perform full-load test. Ensure all load switches are in ON position on 500-amp test stand, and
increase alternator speed to 5,000 rpm. Set load to 182 amps/mm, record results. Refer to table 18-2
for diagnosis.
Table 18-1. No-Load Test.
AhdPS(28v) 28V VOLTS 14v
161-200
21-25
10.5-12.5
161-200
26-30
13-15
161-200
31-35
15.5-17.5
80-119
21-25
10.5-12.5
80-119
26-30
13-15
80-119
31-35
15.5-17.5
IPS (28V)
161-200
28V VOLTS 14v
!
DIAGNOSIS
21-25
10.5-12.5
161-200
26-30
13-15
161-200
31-35
15.5-17.5
80-119
21-25
10.5-12.5
80-119
26-30
13-15
80-119
31-35
15.5-17.5
C
DIAGNOSIS
Test bench battery is discharged (or
defective). Allow to charge (or replace).
Give time to stabilize while monitoring
VOLTS. If VOLTS rise above normal range
(26-30 volts), regulator and/or tube
assembly must be replaced. If AMPS fall,
charging systems OK
STOP TEST. Regulator and/or tube
assembly must be replaced. Refer to static
testing, task c.
Alternator and/or regulator must be
repaired or replaced. Refer to table 18-3.
Regulator OK Refer to table 18-2.
STOP TEST. Bench malfunction or wiring
error.
Table 18-2. FullLoad
Test.
‘Ikst bench battery is discharged (or
defective). Allow to charge (or replace).
Charging system OK
STOP TEST. Regulator and/or tube
assembly must be replaced. Refer to static
testing, task c.
Alternator and/or regulator must be
replaced. Refer to table 18-4.
Increase load.
STOP TEST. Test bench malfunction or
wiring error.
18-4
