Lincoln Electric SA-250 manual Bearings, Commutator & Brushes

3.Change the crankcase oil at regular intervals using the proper grade of oil as recommended in the engine operating manual.

4.Change the oil filter in accordance with the instruc- tions in the engine operator’s manual. When the filter is changed, add a quart of oil to the crankcase to replace the oil held in the filter during operation.

5.Inspect the air filter daily - more often in dusty con- ditions. When necessary, clean or replace. The filter should never be removed while the engine is running.

6.Change the diesel fuel filters every 500 hours of operation.

7.Fan belts tend to loosen after the first 30 or 40 hours of operation. Check and tighten if neces- sary. DO NOT OVERTIGHTEN.

8.Put a drop of oil on the “Current Range Selector” shaft at least once every month.

9.See the engine manufacturer’s Operating Manual for detailed engine maintenance and troubleshoot- ing instructions.

Cooling System

The SA-250 is equipped with a pressure radiator. Keep the radiator cap tight to prevent loss of coolant. Clean and flush the cooling system periodically to pre- vent clogging the passage and overheating the engine. When antifreeze is needed, always use the permanent type.

Bearings

This welder is equipped with a double-shielded ball bearing having sufficient grease to last indefinitely under normal service. Where the welder is used con- stantly or in excessively dirty locations, it may be nec- essary to add one-half ounce of grease per year. A pad of grease one inch wide, one inch long, and one inch high weighs approximately one-half ounce. Over-greasing is far worse than insufficient greasing.

When greasing the bearings, keep all dirt out of the area. Wipe the fittings completely clean and use

clean equipment. More bearing failures are caused by dirt introduced during greasing than from insuffi- cient grease.

Commutator & Brushes

WARNING

Uncovered rotating equipment can be dangerous. Use care so your hands, hair, clothing or tools do not catch in the rotating parts. Protect yourself from particles that may be thrown out by the rotat- ing armature when stoning the commutator.

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The generator brushes are properly adjusted when the welder is shipped. They require no particular attention. DO NOT SHIFT THE BRUSHES or adjust the rocker setting. Shifting of the brushes may result in:

•change in machine output

•commutator damage

•excessive brush wear

Periodically inspect the commutator, slip rings and brushes by removing the covers. DO NOT remove or replace these covers while the machine is running.

Commutators and slip rings require little attention. However, if they are black or appear uneven, have them cleaned by an experienced maintenance man using fine sandpaper or a commutator stone. Never use emery cloth or paper for this purpose.

NOTE: If the welder is used in dirty or dusty locations, or if the welder is not used for prolonged periods of time, it may be necessary to clean the commutator and slip rings more often.

Replace brushes when they wear within 1/4” of the pigtail. A complete set of replacement brushes should be kept on hand. Lincoln brushes have a curved face to fit the commutator. Have an experienced mainte- nance man seat these brushes by lightly stoning the commutator as the armature rotates at full speed until contact is made across the full face of the brushes. After stoning, blow out the dust with low pressure air.

To seat the slip ring brushes, position the brushes in place. Then slide one end of a piece of fine sandpa- per between slip rings and brushes with the coarse side against the brushes. With slight additional finger pressure on top of the brushes, pull the sandpaper around the circumference of the rings, in direction of rotation only - until brushes seat properly. In addition, stone slip ring with a fine stone. Brushes must be seated 100%.

Arcing or excessive exciter brush wear indicates a possible misaligned shaft. Have an authorized Field Service Shop check and realign the shaft.