Lincoln Electric IM402-B manual Operation, Duty Cycle

OPERATION

Safety Precautions

WARNING

ELECTRIC SHOCK can kill.

• Do not touch electrically live parts or electrode with skin or wet clothing.

•Insulate yourself from work and ground.

•Always wear dry insulating gloves.

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FUMES AND GASES can be dangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust to remove fumes from breathing zone.

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WELDING SPARKS can cause fire or explosion.

•Keep flammable material away.

•Do not weld on closed containers.

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ARC RAYS can burn eyes and skin.

• Wear eye, ear and body protection.

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See additional warning information at the front of this operatorʼs manual.

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Be sure the Idealarc 250 is properly installed, and that all accessories are properly hooked up before attempting operation.

DUTY CYCLE

This machine is rated at a 30% duty cycle at 250 amps or 50% duty cycle at 200 amp output. Duty cycle is based on a 10 minute period. Therefore, the welder can be loaded at 200 amperes for 5 minutes out of each 10 minute period. Higher duty cycles can be used at lower currents; see rating plate information.

CONTROL OPERATION

A. Current Control Handle

Rotating the hand wheel raises and lowers the output current allowing the operator to dial the desired current. Clockwise rotation reduces the current while counter-clockwise rotation increases the current. Turning the current control handle also drives the output pointer at the bottom of the nameplate which indicates the stick welding current at NEMA arc volts.

B. Polarity Switch

Turn the arc polarity switch in the upper right hand corner of the case front to AC, DC(-) or DC(+) as required for the particular application.

DO NOT CHANGE POLARITY SWITCH WHILE WELDING. Doing this can seriously damage the switch.

C. TIG Welding

The Idealarc 250 with the optional Hi-Freq is an inexpensive equipment combination for part- time production or repair TIG welding of alu- minum, magnesium, thin stainless steel and many space-age metals. The Idealarc 250 can be used for normal stick electrode welding with the Hi-Freq attached.

CAUTION

Reduce the Idealarc 250 duty cycle by 50% when AC TIG welding, i.e., the welder should be operated for only two and one half minutes out of every ten at rated current of 200 amperes.

The Hi-Freq includes high frequency generator, gas valve and needed controls. It operates on 115V, 50/60 Hz AC power.

NOTE: The Hi-Freq unit includes an R.F. bypass capacitor kit for power source protec- tion. Installation instructions are in the kit. (When using the Idealarc 250 with any other high frequency equipment, an R.F. bypass capacitor must be installed. Order Kit T12246.) To provide protection, the welder grounding stud or frame must be connected to ground (see instructions on grounding in Machine Installation section). Also follow the grounding instructions given in the Hi-Freq Instruction manual.

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