Flashing Voltage Test Procedure - Lincoln Electric SAE-300 HE Service Manual

LINCOLN ELECTRIC

FLASHING VOLTAGE TEST PROCEDURE

Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized
repairs performed on this equipment may result in danger to the technician or machine operator and will
invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety
notes and precautions detailed throughout this manual. If for any reason you do not understand the test
procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department
for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
TEST DESCRIPTION
This test checks the Exciter Rotor Flashing Voltage.
MATERIALS NEEDED
Volt/Ohmmeter
Wiring Diagram
TEST PROCEDURE
1. Turn off the engine on the SAE-300 HE machine.
2. Lift the left and right side covers and secure them with the hooks provided.
3. Remove the 15 Amp fuse from the fuse holder located on the back of the control panel on the right
side. (Operator's right when facing the control panel.)
4. Remove the cover from the exciter / auxiliary power alternator.
5. Disconnect any weld cables or power cords.
6. Set the volt/ohmmeter for DC volts and attach the leads to the brush terminals. See Figure F.10.
NOTE: The negative brush is the one closest to the winding of the exciter and normally has a red
wire attached.
7. Place the idle switch in the "High" idle position, start the engine and measure the voltage.
8. If the voltage measures between 3 and 6 volts, the flashing is normal and the test is complete.
9. If the voltage measures zero or very near zero, move the meter leads to the weld output terminals.
Measure the voltage and observe the polarity of the DC voltage.
10. If the voltage measures between 3 and 6 volts DC and the polarity is the same as indicated on the
weld output terminals, do the following: Check for a faulty flashing/flywheel bridge rectifier. Check
for a poor connection between the welding generator brush holders, the flashing/flywheel rectifier,
the field bridge rectifier and slip rings. See Wiring Diagram.
11. If the voltage is zero or very near zero, or if the polarity does not match the polarity indicated at the
weld terminals, replace the fuse removed in step 3, perform the Field Flashing Procedure and
repeat the above steps.
12. If the Field Flashing Procedure does not correct the problem, perform the Welding Generator Brush
And Commutator Inspection And Service Procedure, the Weld Circuit Ground And Short Circuit Test
Procedure and the Shunt Field Coil Resistance Ground Test Procedure.
SAE-300® HE Service Manual
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