Komatsu 830E-AC Shop Manual page 250

BENCH TESTING
Perform the following on-bench tests when:
• On-vehicle test results are not available.
• Confirming on-vehicle test results.
Equipment
• Voltmeter, 0-40 Volt range (Digital type preferred)
• Ammeter, 0-400 ampere range (Digital, Inductive
type preferred.)
• Test bench with 30-40 hp motor able to drive the
alternator to 8000 rpm. Mount the alternator on
the test bench per the bench manufacturer's
instructions. Ensure the test bench batteries are
at 95% or higher state of charge.
Identification Record
List the following items for troubleshooting:
Alternator model number ______________
Regulator model number ______________
Set point(s) listed on regulator __________
Advanced Troubleshooting
a. A voltage reading at the regulator set point of
± 0.2 Volts is considered normal.
b. The alternator rated output (listed on the
nameplate) within ± 10% is determined at
5000 rpm.
D10-20
Bench Test 1: No-Load Test
1. With the battery connected and no electrical
load, operate the alternator at 5000 rpm.
2. Compare the test results to the No Load Test,
Table 10-5, and take the appropriate action, as
stated in the table.
Amps
HIGH
HIGH
HIGH
LOW
LOW
LOW
Battery Charging Alternator
Table 10-5: NO LOAD TEST
Volts Diagnosis
LOW Test bench battery is discharged
or defective. Allow to charge or
replace.
NORMAL Allow time to stabilize while moni-
toring the Volts. If the Volts
increase above the normal range,
the regulator and/or field coil must
be replaced. If the amps
decrease, the charging system is
good.
HIGH The regulator and/or field coil
must be replaced. Go to Static
Testing.
LOW The alternator and/or regulator
must be repaired or replaced. Go
to Bench Test 3.
NORMAL The regulator is good. Go to
Bench Test 2.
HIGH Stop the test. The alternator is
defective, bench is not working
properly, or the alternator is wired
improperly to the bench.
D10003 07/06