CHAPTER 3: OPERATING INSTRUCTIONS
PHASEMASTER™ 6 DIRECT ENERGY WELDING CONTROL
990-083
3-19
Since polarity can be an important consideration in half-cycle welding of some material combinations, be sure to
check the weld schedule results using both positive and negative polarity. Polarity can be changed in the
PROGRAM State. The general rule is that the more resistive material, or the thinner material, should be placed
against the negative (-) electrode.
CAUTION:
If weld schedules are chained together, do NOT change polarity. All schedules in the chain must
have the same polarity or the relay contacts may be damaged.
Output Voltage vs Weld Quality
The output voltage is controlled by the Taps on the Welding Transformer. Figures 3-3 and 3-4 show two
extreme conditions, (A) and (B), which can be used to weld two resistive workpieces such as Nickel-to-
Nickel.
•
Test Condition A shows the use of the HIGH (#3) Primary Tap and a low %CURRENT. As a result the
current flows for short periods during each of the 3 cycles. This causes a large temperature deviation
around the average temperature. Metal spattering and/or electrode sticking might occur during this
condition.
•
Test Condition B shows the use of the LOW (#1) Primary Tap and a high %CURRENT. As a result,
equivalent power is obtained by a lower voltage and the current flows for a greater portion of each cycle.
This results in a smaller temperature deviation around the average temperature.
Conditions:
A
B
Transformer
X16/230
X16/230
Primary Tap
3
1
Secondary Tap
COM – LO
COM – LO
Output Voltage
3.8
2.9
Workpiece
Resistive
Resistive
%CURRENT
40
75
WELD CYCLES
3
3
