Red-D-Arc DC-600 Operator's Manual page 23

B-9
ARC STRIKING WITH DC-600 AND THE NA-3
START BOARD
When electrical strikeouts exceed 1 3/4" (44.4mm) an
NA-3 Start Board may be required to improve arc
striking.
When the NA-3 Start Board is used to improve arc
striking, use the following procedures:
1. Set start time at 0.
2. Set NA-3 start current and start voltage at mid-
range.
3. Set the NA-3 output current and voltage to the
proper settings for the welding procedure to be
used.
4. Turn the Start Board Timer to maximum.
5. Set Start Board current and voltage control.
a. Set the Start Board current control to 1 1/2
dial numbers below that set on the NA-3 cur-
rent control.
b. Set the Start Board voltage control equal with
the NA-3 voltage control setting.
NOTE: These Start Board current and voltage
settings result in a start up current that is lower
than the NA-3 current setting and approximately
equal with the NA-3 voltage setting for the desired
welding procedure.
OPERATION
6. Establish the correct arc striking procedure with
the NA-3 Start Board timer set at maximum.
a. For the best starting performance, the NA-3
Open Circuit Voltage Control and Voltage
Control setting should be the same. Set the
Inch Speed Control for the slowest inch
speed possible.
b. To adjust the Open Circuit Voltage Control to
get the best starting performance, make
repeated starts observing the NA-3 voltmeter.
When the voltmeter pointer swings smoothly up to
the desired arc voltage, without undershooting or
overshooting the desired arc voltage, the Open
Circuit Voltage Control is set properly.
If the voltmeter pointer overshoots the desired
voltage and then returns back to the desired volt-
age, the Open Circuit Voltage Control is set too
high. This can result in a bad start where the wire
tends to "Blast off."
If the voltmeter pointer hesitates before coming up
to the desired voltage, the Open Circuit Voltage
Control is set too low. This can cause the elec-
trode to stub.
c. Set NA-3 Start Board current and voltage as
close to the welding procedure current and
voltage as possible.
NOTE: The Start Board current and voltage
should be as close as possible to the welding pro-
cedure current and voltage, while still getting sat-
isfactory starts.
d. Set the start time to as low a time as possible
while still getting satisfactory starts.
7. Start and make the weld.
DC-600
B-9