Figure 3-6 are attached to the system and manually set for
the desired pulse on and off times. Always refer to the
operation manual for a list of set-up options for this
process mode and applications. Figure 3-7 shows how the
adjustments regulate the pulse on and off times to control
the length of the metal transfer period of the weld cycle.
Power Supply Installation
A power supply should be installed in an area that is
free of dust, dirt, and fumes. There should also be
adequate ventilation, so that machine heat can escape.
Dirt and heat will cause a power supply to overheat,
ruining the internal components. The area selected for
installation should be free of objects blocking the flow of
air into and out of the machine. The machine should not
be exposed to moisture, since electronic components may
pick up moisture and fail. Most machine manufacturers
require a defined space around the power supply for air
circulation; warranties are voided if these areas are not
provided.
Utilities supply electrical power at 60 cycles (hertz)
and at various input voltages requested by the user.
Machines using other than 60 cycle power are specially
made at the factory for this requirement. The required
fuse size for the incoming power is always shown on the
data label. See Figure 3-8. The fuse panels should always
be close to the power supply. This makes it possible to
30 Gas Metal Arc Welding Handbook
Figure 3-5. This machine has several welding programs
already installed by the manufacturer. (Lincoln Electric Co.)
Figure 3-6. Pulser units of this type may be added onto
standard CV power supplies.The pulse range is from 30 to 500
pulses per second. (MK Products, Inc.)
Transition
current
Average
current
Background
current
Less heat
More heat
1MS
1MS
1MS 1MS
1MS 1MS 1MS
1MS
Metal
transfer
Metal
transfer
Current
(amps
DCRP)
Figure 3-7. Adjusting for a greater number of pulses per
second results in more heat and increases metal transfer.
Adjusting for fewer pulses per second results in less heat and
decreases metal transfer.
Peak
voltage
Average
voltage
Volts
Milliseconds