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CHAPTER 5: OPERATING INSTRUCTIONS
875DP/500DP/500HV DUAL PULSE
RESISTANCE WELDING
POWER SUPPLIES
5-2
990-290
Weld Head Parameters
There are two critical weld head parameters that you must pay particular attention to: electrode force and
electrode face area.
Electrode Force: 1 Install the correct electrodes in the electrode holders on the weld head. Refer to
table 5-1 for electrode material recommendations.
2 Set the force adjustment knob on the weld head to set the firing force. Start at a
moderate force setting, 3 on a Unitek Peco Weld Head. Figure 5-1 illustrates the
effect of electrode force on the work piece.
3 Adjust the air pressure for air operated weld heads.
HEAT
Excessive
Insufficient
CAUSE
PROBLEM
Parts Overheating
Weak Weld
Insufficient Nugget
Metal Expulsion
Warping
Discoloration
Electrode Damage
PRESSURE
Excessive
Insufficient
CAUSE
PROBLEM
Parts Overheating
Weak Weld
Insufficient Nugget
Metal Expulsion
Warping
Discoloration
Electrode Damage
TIME
Excessive
Insufficient
CAUSE
PROBLEM
Parts Overheating
Weak Weld
Insufficient Nugget
Metal Expulsion
Warping
Discoloration
Electrode Damage
%
ENERGY
PULSE
WIDTH
FIRING
FORCE
Figure 5-1. Effects of Excessive or Insufficient Heat, Time and Pressure