Arc Machines 205 WDR - Manual (Page 42)

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O P E R A T O R ’ S M A N U A L
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9. Once the operator manually presses the START button the following events will
occur automatically:
• EVENT 1: PREPURGE - welding gas will start to flow and continue to flow for the entire
weld sequence from the gas source through the power supply to the weldhead.
Complete gas coverage should be obtained before the arc is struck. How long it flows
before the arc is struck is called the PREPURGE time. Minimum programmable time is
5 seconds. Refer to the on line HELP for minimum recommended PREPURGE time for
each weldhead.
• EVENT 2: ARC START - when PREPURGE time is complete the gas will continue to
flow and a high frequency pulse will be generated to establish an arc between the
electrode and the weld joint.
Note
When the system initiates it waits for 0.5 second for either an arc start or arc fault response.
• EVENT 3: UPSLOPE - when an UPSLOPE is programmed the arc will be initiated at the
programmed START LEVEL amps. As soon as the arc is established the amps will
ramp up to the programmed Level 1 PRIMARY AMPS value. When an UPSLOPE is not
programmed, the arc will be initiated at the Level 1 PRIMARY AMPS value.
Once the arc is established and PULSE MODE programmed to ON the weld current will
pulse between the PRIMARY and BACKGROUND amp values. The amount of time it
remains at these values is determined by the PRIMARY and BACKGROUND PULSE
times.
In most cases, rotation of the arc should not begin until full penetration of the weld has
been achieved. Once the arc is established the TRAVEL START DELAY time will begin
to count. When this time has counted down, the weld schedule will advance to Level 1
and begin rotating the electrode at the Level 1 programmed travel speed for the Level 1
programmed number of seconds or degrees of rotation.
After the TRAVEL START DELAY time is complete, the electrode will begin to travel in
one of the 3 programmable PULSE MODES:
OFF - Prevent rotation from occurring.
CONTINUOUS - Rotates the electrode continuously at the PRIMARY TRAVEL
speed, regardless of PULSE MODE.
STEP - Rotates the electrode, alternating between the PRIMARY TRAVEL speed
and the BACKGROUND TRAVEL speed. This function is synchronized to the
PRIMARY PULSE time and the BACKGROUND PULSE time.