Troubleshooting & repair, Rotor voltage test (continued) – Lincoln Electric VANTAGE 400 User Manual
Page 93
ROTOR VOLTAGE TEST (CONTINUED)
10. If the meter reading indicates battery volt-
age, about 12 to 14 VDC, the rotor may be
open, or the brushes may be faulty or not mak-
ing proper contact with the slip rings. Perform
the Rotor Resistance Test, and Brush and
Slip Ring Service Procedure.
11. If the voltage measures about 3 to 5 VDC,
the generator is not building-up to normal out-
put even though the flashing circuit appears to
be functioning normally. This condition could
be caused by one of several failed compo-
nents or connections. Continue with the fol-
lowing test.
12. Check the field bridge rectifier, and capacitor;
also check the wiring and terminals connecting
them. See the wiring diagram.
13. Perform the Rotor Resistance Test.
14. Perform the Stator Short Circuit and Ground
15. When the Stator short circuit and ground test
has been completed, reconnect leads 6 and
5H to the field bridge rectifier, (D3). All other
stator leads should remain disconnected and
isolated at this time.
16. Be sure that there are no leads of any kind
across any of the stator windings, except the
6A - 5H winding. Examine stator wiring for
damage, pinched leads, chafed insulation, etc.
If necessary, disconnect and isolate the stator
output leads as close to the starter as possible.
See wiring diagram.
17. All of these disconnected leads should be insu-
lated, and/or positioned so they cannot come
in contact with any other wiring or chassis
ground and cannot be damaged by moving
parts when the engine is running.
18. Re-start the machine and measure the rotor
voltage.
19. If rotor voltage continues to read significantly
lower than 120 VDC, the Stator is probably
defective and should be replaced.
Note: The field bridge rectifier and field capacitor
may appear to function normally when tested inde-
pendently, but may malfunction when placed under
the stress or normal operation. For this reason, It
is recommended that the bridge rectifier and the
capacitor be replaced with known good compo-
nents before replacing the stator.
TROUBLESHOOTING & REPAIR
F-45
F-45
VANTAGE® 400