CHAPTER 6: PROCESS DEFINITIONS AND WELD FUNCTIONS
MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
990-280
6-7
Rollspot Function
While the force firing switch remains closed, the weld/cool sequence will be repeated. The cool time
and the rotational speed of the wheel electrodes determines the distance between spots. Assuming a
reasonable wheel speed, the cool period could be reduced so that the spots would overlap. The energy
required for the first spot, Weld 1, should be less than that required for all subsequent spots, Weld 2, in
the sequence.
Rollspot cannot be used in a chain. Dual pulse and/or Footswitch Weld Abort OFF are not permitted in
Rollspot.
The PROGRAM State Screen for the Rollspot Weld Function
In the rollspot application shown on the above screen, the welds would not overlap if the rotational
speed of the wheel exceeded 0.25 inches/second, assuming a spot which is 1/16 inch long, because the
recharge time was approximately 0.050 seconds (refer to Appendix A under Welding Speed) and the
cool time was set to 0.250 seconds.
