Lincoln Electric PM 255 specifications Operating Instructions for Timer KIT

C-2 ACCESSORIES C-2

4.Attach the rectangular 10-pin plug connector on the timer kit wiring harness to the mating receptacle connector located directly behind the removed cover panel. Be sure that the latch on the connec- tor is aligned with the one on the board and insert it until the latch engages.

5.Align the timer panel for installation and carefully insert the printed circuit board and wiring harness through the opening. Make sure the wiring harness is not pinched between panels or between printed circuit board and front panel cover.

6.Secure the timer assembly with either the two sup- plied screws or with the original screws. The instal- lation is now complete. Refer to the following sec- tion for operating instructions.

OPERATING INSTRUCTIONS FOR TIMER KIT

If the optional Timer Kit (K1701-1) is installed, select the desired mode with the selector switch:

A. Normal Welding mode provides weld power only while the trigger switch is depressed. This is the same operation as when the Timer Kit is not installed.

B. 4-Step Trigger interlock mode eliminates the need to hold the gun trigger while welding. It operates in

4steps:

1.Close trigger and establish welding arc.

2.Release trigger and continue welding.

3.Reclose trigger near end of weld.

4.Release trigger again to stop welding.

If the arc is broken while using this feature, the machine will reset to the “trigger off” condition auto- matically.

C. Spot Weld Mode is is used for tack welding parts into position or for spot plug welds to hold thin sheet metal together prior to manual stitch or con- tinuous welding. To use this feature, adjust the On-Time (0-5 seconds) as appropriate to obtain the desired results. Closing the trigger initiates a single timed spot weld cycle. Plug welds are made by using a punch to make a 3/16" (5 mm) diameter hole in the top sheet and arc welding through the hole into the back sheet.

To make spot plug welds, punch 3/16" (5 mm) holes in the top sheet. Set the Spot Time control to approximately 1.2 seconds and set the procedure for the metal thickness to be welded. Install spot weld nozzle (if available) on gun and press it against the top sheet so the top and bottom sheets are tight together. Close trigger and hold it closed until the arc goes out. If a spot weld nozzle is not used, smoother welds will result by moving the welding wire in a small circle during the weld.

D. Burnback Time control provides manual adjust- ment of the burnback time (0-250 milliseconds) for any selected welding mode. this control should be set as low as possible without the wire “sticking” in the puddle after each weld. Too long of a burnback time may form a “ball” on the end of the wire, or may “flash back” to the gun tip.

E. Run-In Mode is used to adjust the starting wire feed speed. Starting conditions for certain welding applications can be improved with adjustment to the Run-In speed. The control allows for initial starting speeds from 50 - 150 IPM. After the arc is started, the set point on the wire feed speed control will dominate. Note that the Run-in is not functional with the spool gun. Also note that if Run-in is set fully counter clockwise to “OFF”, Run-in speed will equal the preset WFS on the machine.

PM 255