
LINCOLN ELECTRIC
SAE-300® HE Service Manual
39
11.
If the resistance measured at the positive terminal is low, carefully examine the interpole coils and
the heavy leads and the brush holders connected to the interpole coils. Check for damaged, dirty or
missing brush holder insulators. Check for a damaged or dirty weld output positive terminal.
12.
If the resistance measured at the negative terminal is low, examine the coarse current control unit,
the series coils and the heavy leads and brush holders connected to them. Check for damaged, dirty
or missing brush holder insulators. Check for a damaged or dirty weld output negative terminal. If
necessary, disconnect the coarse current control unit and test it separately. See the
Control Unit (Variable Reactor) Inspection and Service Procedure
13.
Test for a short circuit condition between the positive and negative circuits.
14.
With the brushes still isolated as described above, check the resistance between the two weld
output terminals. The resistance should be very high, 500,000 (500k) Ohms minimum.
15.
If the resistance measurement is too low, check the heavy weld current carrying leads and
connections for damaged insulation or dirt buildup between the negative (series coils) and positive
(interpole coils) circuits. If the low resistance point is between the stator coils, the coils will require
replacement or repair.
Field Flashing Procedure:
This procedure restores or corrects the residual magnetism in the welding generator. This
procedure should be performed if there is no residual voltage output or if the polarity of the
residual output is reversed.
16.
Turn off the engine on the SAE-300 HE machine.
17.
Place the fine current / OCV control to the maximum setting.
18.
Connect a DC power source of about 12 Volts to the exciter brush terminals. (The battery works
well for this purpose.) Connect the positive lead to the positive brush terminal and the negative
lead to the negative terminal and apply the voltage for about 3 to 5 seconds.
NOTE:
If the residual output was present but the polarity was reversed, the above procedure should
be used but the voltage used to flash the fields must be at least 24 Volts DC.
19.
When all testing is complete, connect any previously disconnected leads, attach sheet metal cover
protecting the welder generator brushes and close the left and right side covers. See Wiring
Diagram.
Содержание SAE-300 HE
Страница 8: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 3 Theory of Operation Figure F 1 Block Diagram ...
Страница 51: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 46 Figure F 13 Rocker w marks ...
Страница 54: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 49 Figure F 14 Brush spring Figure F 15 Windings insulated wedge ...
Страница 55: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 50 Figure F 1 Insulator spring locations Figure F 2 Shaft tube ...
Страница 64: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 59 Figure F 22 Rheostat terminal locations ...
Страница 68: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 63 Figure F 25 Rotor removal ...
Страница 75: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 70 Figure F 28 Sling lift ...
Страница 79: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 74 Figure F 30 Current sense board plug location ...
Страница 83: ...LINCOLN ELECTRIC SAE 300 HE Service Manual 78 Figure F 32 Rheostat terminal locations ...