MAINTENANCE | ||
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COMMUTATOR AND BRUSH MAINTENANCE
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.
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 pig- tail. A complete set of replacement brushes should be kept on hand. Lincoln brushes have a curved face to fit the commutator. Have an experienced maintenance man seat these brushes by lightly stoning the commu- tator as the armature rotates at full speed until contact is made across the full face of the brushes. After ston- ing, 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 sandpaper between slip rings and brushes with the coarse side against the brushes. With slight additional finger pres- sure 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 pos- sible misaligned shaft. Have an authorized Field Service Shop check and realign the shaft.
COOLING SYSTEM
The SAM welders are equipped with a pressure radia- tor. Keep the radiator cap tight to prevent loss of coolant. Clean and flush the cooling system periodi- cally to prevent clogging the passage and overheating the engine. When antifreeze is needed, always use the permanent type.
CONTACTOR MAINTENANCE
Where the output contactor is operated frequently when tacking or making short welds, turn the engine off and inspect the contactor every three months:
1.be sure the mating surfaces of silver contacts are not worn and all make contact at approximately the same time.
2.Make sure the springs and holders are not broken or out of adjustment. Approximate spring com- pression after making contact is 1/8”. Less than 1/16” compression indicates worn contacts that should be replaced.
3.Make sure the moving contact or other moving parts are not binding.
4.Check interlock contacts and springs. Be sure mounting screws are tight.
SAM400 & 650 | APR97 |
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