Output Cable Guidelines; Cable Inductance And Its Effects On Welding - Lincoln Electric POWER WAVE STT Operator's Manual

POWER WAVE ® STT ® MODULE (CE)
Percent
Duty
Amperes
Cycle
200 60
200 100
225
20
225 40 & 30
250
30
250
40
250 60
250
100
300 60
325 100
350
60
400 60
400 100
500
60
** Tabled values are for operation at ambient temperatures of 40°C and below. Applications above 40°C may require cables larger than recommended, or cables rated
higher than 75°C.
GENERAL GUIDELINES
• Select the appropriate size cables per the "Output Cable
Guidelines" (See Table A.1. Excessive voltage drops caused
by undersized welding cables and poor connections often
result in unsatisfactory welding performance. Always use the
largest welding cables (electrode and work) that are
practical, and be sure all connections are clean and tight.
Note: Excessive heat in the weld circuit indicates undersized
cables and/or bad connections.
• Route all cables directly to the work and wire feeder, avoid
excessive lengths and do not coil excess cable. Route the
electrode and work cables in close proximity to one another
to minimize the loop area and therefore the inductance of the
weld circuit.
• Always weld in a direction away from the work (ground)
connection.
See Table A.1 for copper cable sizes recommended for different
currents and duty cycles. Lengths stipulated are the distance
from the welder to work and back to the welder again. Cable
sizes are increased for greater lengths primarily for the purpose
of minimizing cable drop.
TABLE A.1

OUTPUT CABLE GUIDELINES

CABLE SIZES FOR COMBINED LENGTHS OF ELECTRODE AND WORK CABLES
(RUBBER COVERED COPPER - RATED 75°C)**
0 to 50 Ft. 50 to 100 Ft.
2 2
2 2
4 or 5 3
3 3
3
3
2 2
1 1
1
1
1 1
2/0 2/0
1/0
1/0
2/0 2/0
3/0 3/0
2/0
2/0
100 to 150 Ft.
2
2
2
2
2
1
1
1
1
2/0
2/0
2/0
3/0
3/0
CABLE INDUCTANCE AND ITS EFFECTS ON
WELDING
Excessive cable inductance will cause the welding performance
to degrade. There are several factors that contribute to the
overall inductance of the cabling system including cable size,
and loop area. The loop area is defined by the separation
distance between the electrode and work cables, and the overall
welding loop length. The welding loop length is defined as the
total of length of the electrode cable (A) + work cable (B) + work
path (C) (see Figure A.3 below). To minimize inductance always
use the appropriate size cables, and whenever possible, run the
electrode and work cables in close proximity to one another to
minimize the loop area. Since the most significant factor in cable
inductance is the welding loop length, avoid excessive lengths
and do not coil excess cable. For long work piece lengths, a
sliding ground should be considered to keep the total welding
loop length as short as possible.
POWER
WAVE
B
A-4
INSTALLATION
150 to 200 Ft. 200 to 250 Ft.
1 1/0
1 1/0
1 1/0
1 1/0
1 1/0
1 1/0
1 1/0
1 1/0
1/0 2/0
2/0 3/0
2/0 3/0
3/0 4/0
3/0 4/0
3/0
4/0
FIGURE A.3
A
C
WORK