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LINCOLN ELECTRIC
SAE-300® HE Service Manual
55
CHOKE 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 will determine if the Choke is open, shorted (turn to turn) or grounded.
MATERIALS NEEDED
Volt/Ohmmeter
Wiring Diagram
TEST PROCEDURE
1.
Turn off the engine on the SAE-300 HE machine.
2.
Open the side covers and secure them with the hooks provided.
3.
Locate the choke assembly (attached to the rear of the front panel) and perform the following tests.
See Wiring Diagram.
4.
Open:
No weld output. Using a volt/ohmmeter, test the resistance from the top choke terminal to
the negative output terminal. See Wiring Diagram. Typical resistance is less than one ohm.
5.
Turn To Turn Short:
Reduced inductance, arc instability, excessive heating of the choke. Check for
any physical signs of arcing within the choke assembly. See Wiring Diagram.
6.
Choke Coil Grounded:
Reduced inductance, alternate weld current path. Electrically isolate the
choke coil by disconnecting the leads from the top and bottom choke terminals. Using a
volt/ohmmeter, check the resistance from choke coil to chassis ground. Resistance should be at
least 500,000 ohms. See Wiring Diagram.
7.
If any of the tests fail, the choke may be faulty.
8.
Choke Removal And Replacement Procedure
9.
Connect any previously disconnected leads and close the side covers. See Wiring Diagram.
Summary of Contents for SAE-300 HE
Page 8: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 3 Theory of Operation Figure F 1 Block Diagram ...
Page 51: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 46 Figure F 13 Rocker w marks ...
Page 64: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 59 Figure F 22 Rheostat terminal locations ...
Page 68: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 63 Figure F 25 Rotor removal ...
Page 75: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 70 Figure F 28 Sling lift ...
Page 79: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 74 Figure F 30 Current sense board plug location ...
Page 83: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 78 Figure F 32 Rheostat terminal locations ...