Arc Machines 227 - Manual (Page 36)

MODEL 227
OPERATION MANUAL
Doc # 740063 Rev E
SECTION IV - SYSTEM FUNCTIONS
4.3 WELD SEQUENCE
5. EVENT 5: LEVEL 2 TO LAST PROGRAMMED LEVEL - As the arc is
rotated around the weld it is usually necessary to program changes in the
current, pulse times, modes and rotation speed. These changes are called
LEVELS and up to 100 can be programmed for each sequence. Each
LEVEL contains the same functions and options as EVENT 4. In TIMER
MODE AUTO each LEVEL TIME sets the duration of that level. TIMER
MODE MANUAL the system will stay in a programmed level until
MANUAL ADVANCED by the Operator (from the Remote Pendant).
6. EVENT 6: DOWNSLOPE - When the last programmed LEVEL is
complete the WELD SEQUENCE will begin the process of stopping
as follows:
1. Current and Oscillator DOWNSLOPE - To avoid cratering and cracking
of the weld the current and oscillator need to be reduced slowly. The last
LEVEL PRIMARY-AMP value and BACKGROUND-AMP value (if
pulsed) and OSC AMPLITUDE will start to decrease towards 0. The
time it takes to reach arc cutoff (about 3 amps) is called the
DOWNSLOPE time and it is programmable.
2. WIRE STOP DELAY TIMER - At the end of the last Level the WIRE
STOP DELAY time will start counting. The WIRE will continue to feed
until this time is complete. When the wire quits feeding the wire will
automatically retract (go in reverse) for the programmed RETRACT
TIME.
3. AVC STOP DELAY - At the end of the last Level the AVC STOP
DELAY time will start counting. The AVC will continue to operate until
this time is complete.
NOTE
The ROTATION function does not have a STOP DELAY. The Weld Head
will continue to TRAVEL for the DOWNSLOPE time and then turn off.
7. EVENT 7: POSTPURGE - At the end of DOWNSLOPE, when the current
is less than 3 amperes, the arc will go out. All functions except gas flow will
stop. The gas should not be stopped until the weld and electrode are cooled
enough to prevent oxidation. How long the gas continues to flow is called
the POSTPURGE TIME.
4.10