Arc Welding Equipment Prepared by Dr. Dale Carpentier and Mr. Barry Brazelton Monroe Area High School Modified by Georgia Agriculture Education Curriculum Office June 2007

Miller Dialarc 250/250P AC/DC Arc Welder and equipment Miller Dialarc 250/250P AC/DC Arc Welder and equipment E.Q. - What are the parts and functions of the arc welding outfit?

Power Switch Used to turn welder on and off Used to turn welder on and off

Range Selector Switch Use switch to select ac or dc welding amperage. High and Low range If amperage is in overlapping range use lower range for better amperage control. Do not change position of switch while welding.

Amperage Adjustment Control Use control to adjust amperage. Use control to adjust amperage. Inside dial is ac low and high range. Inside dial is ac low and high range. Outside ring is dc low and high range. Outside ring is dc low and high range. Do not adjust when circuit is closed. Do not adjust when circuit is closed.

Circuit Breaker, CB1 If CB1 opens, weld output drops to the minimum of the range selected, and cannot be adjusted by the Amperage Adjustment control. Press button to reset breaker.

Duty Cycle Duty Cycle is the percentage of 10 minutes that unit can weld at rated load without overheating. Duty Cycle is the percentage of 10 minutes that unit can weld at rated load without overheating. 100% duty 100 amps or less. 100% duty 100 amps or less. Exceeding duty cycle can damage unit by overheating. Exceeding duty cycle can damage unit by overheating.

Cable attachments for AC & DC Cables are attached for AC welding. Do not walk on cables. Do not change to DC welding without instructor approval.

Ground Clamp Must be attached to welding table or metal to be welded in order to complete welding circuit. Must be attached to welding table or metal to be welded in order to complete welding circuit. You must clean painted, dirty, or rusted metal to get a good ground. You must clean painted, dirty, or rusted metal to get a good ground.

Electrode Holder Insulated. Holds electrodes while welding. Do not burn electrodes shorter than 1 inch.

Welding Table Must be made of metal. Must be made of metal. Hang cables on hooks rather than laying on floor. Hang cables on hooks rather than laying on floor. Position exhaust vent near welding base metal. Position exhaust vent near welding base metal.

Welding Electrodes Standard diameter sizes are 3/32”, 1/8”, and 5/32” rod is for new metal. Attractive bead. Easy to weld with rod is for used and dirty metal. Deep penetration. Most utilitarian rod for farm and ranch use rod is a fast fill rod that produces attractive welds is a low hydrogen rod. Best with DCRP.

Welding Helmet or Shield Used to protect face and eyes. Used to protect face and eyes. Must have a shade10 lens, minimum. Must have a shade10 lens, minimum.

Other Equipment Chipping hammer Used to remove slag. Welding gloves. Used to protect hands. Wire brush and file. Used to clean metal. Tongs Used to carry hot metal.