Lincoln Electric SVM194-A service manual Check for Max output

F-39	TROUBLESHOOTING AND REPAIR	F-39
	ROCKER ADJUSTMENT PROCEDURE (continued)

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Check that the brush holders are properly installed and positioned correctly. See the Welding

Generator Brush and Commutator Inspection and Service procedure.

Start the engine, place the idle switch in the high idle position, and seat the brushes using a com- mutator stone. See the Welding Generator Brush and Commutator Inspection and Service Procedure.

Place the range selector switch in the maximum position. Use a load bank to apply a 100% duty cycle load (250 amps @ 30 volts). Look at the brushes while the load is applied. If excessive sparking is observed, adjust the rocker position to minimize sparking. Generally, moving the rocker slightly in the direction of the armature rotation will reduce sparking.

Continue running the machine under load for at least 30 minutes to bring the machine up to normal operating temperature and to fully seat the brush- es.

Check for Max output.

Remove the load, set the fine current control and rheostat to maximum, and then adjust the load bank to apply a 300 Amp load to the machine.

Measure the output voltage, it should read:

• From 33 to 42 VDC for Classic® 3000 and Classic® 300D Perkins models.

• From 34 to 48 VDC for Classic® 300D Kubota models.

Measure the engine RPM, it should measure:

• From 1780 to 1810 RPM, for Classic® 3000 mod- els

• From 1650 to 1750 RPM, for Classic® 300D Perkins models

• From 1790 to 1810 RPM, for Classic® 300D Kubota models

If the engine RPM is not within specification, Perform the Engine RPM Adjustment Test, if the engine high idle RPM is normal, but the load RPM is significantly less than specified above, the engine or governor may be malfunctioning. See the engine troubleshooting procedures in this manual and/or have the engine serviced or repaired by a qualified engine technician.

If the weld output voltage is lower than specified above, the rocker position will need to be adjusted. Generally, moving the rocker opposite the arma- ture rotation direction will increase output voltage. When making this adjustment, the rocker should only be moved in very small increments. The adjustment may need to be repeated several times to achieve the desired result.

Check the OCV, (Open Circuit Voltage) Remove the load and check the voltage at the out- put studs. The voltage should measure from 93 to 99 Volts DC.

After the rocker has been adjusted and the machine is operating normally, the rocker locking screw should be tightened to 70-75 Inch-Lbs.

If new parts had been installed, the new rocker and/or exciter bracket location should be marked with a 1/8" drill mark. See Figure F.1.

CLASSIC® 300D & 300G