Miller Electric KC237900 - Manual (Page 26)

OM-530 Page 22
Table 6-2. Tungsten Size Chart
Electrode Diameter
Pure Tungsten
.010”
.020”
.040”
1/16”
3/32”
1/8”
5/32”
3/16”
1/4”
2% Thorium Alloyed
Tungsten
.010”
.020”
.040”
1/16”
3/32”
1/8”
5/32”
3/16”
1/4”
Zirconium Alloyed
Tungsten
.010”
.020”
.040”
1/16”
3/32”
1/8”
5/32”
3/16”
1/4”
Amperage Range - Polarity - Gas Type
DC-Argon Electrode
Negative/Straight Polarity
Up to 15
5-20
15-80
70-150
125-225
225-360
360-450
450-720
720-950
Up to 25
15-40
25-85
50-160
135-235
250-400
400-500
500-750
750-1000
DC-Argon Electrode
Positive/Reverse Polarity
*
*
*
10-20
15-30
25-40
40-55
55-80
80-125
*
*
*
10-20
15-30
25-40
40-55
55-80
80-125
*
*
*
*
*
*
*
*
* *
*
*
*
*
*
*
*
*
AC-Argon Using
High Frequency
Up to 15
5-20
10-60
50-100
100-160
150-210
200-275
250-350
325-450
Up to 20
15-35
20-80
50-150
130-250
225-360
300-450
400-500
600-800
Up to 20
15-35
20-80
50-150
130-250
225-360
300-450
400-550
600-800
AC-Argon Balanced
Wave Using High Freq.
Up to 10
10-20
20-30
30-80
60-130
100-180
160-240
190-300
250-400
Up to 15
5-20
20-60
60-120
100-180
160-250
200-320
290-390
340-525
Up to 15
5-20
20-60
60-120
100-180
160-250
200-320
290-390
340-525
*NOT RECOMMENDED
The figures listed are intended as a guide and are a composite of recommendations from American Welding
Society (AWS) and electrode manufacturers.
S-0009/8-88
(Green Band)
(Red Band)
(Brown Band)
6-3. SPARK GAP ADJUSTMENT (Figure 6-3)
It is necessary to readjust the spark gaps every three to
four months or when intermittent operation occurs. Nor-
mal spark gap setting is 0.008 in. (0.203 mm).
High-frequency output varies with the spark gap setting.
When a great amount of high frequency is necessary,
the spark gaps can be adjusted to 0.010 in. (0.254 mm).
This, however, increases high-frequency radiation
which increases interference with communications
equipment. It is suggested that a minimum spark gap
setting be used.
IMPORTANT: Spark gaps widen with normal operation.
At regular inspections, check and maintain the spark air
gap to ensure consistent welding results and com-
pliance with FCC radiation regulations.
IMPORTANT: Do not clean or dress points since the
material at the tips is tungsten and impossible to file.
The entire point should be replaced when the tungsten
section has completely disappeared.
This unit is provided with a spark gap assembly located
inside the unit in the lower right side (refer to Parts List
views). To adjust spark gaps, proceed as follows: