Cable Inductance, And Its Effects On Pulse Welding; Negative Electrode Polarity; Voltage Sensing - Lincoln Electric POWER WAVE455M Operator's Manual

A-4
CABLE INDUCTANCE, AND ITS EFFECTS
ON PULSE WELDING
For Pulse Welding processes, cable inductance will
cause the welding performance to degrade. For the
total welding loop length less than
tional welding cables may be used without any effects
on welding performance. For the total welding loop
length greater than
50 ft.(
Welding Cables are recommended. The welding loop
length is defined as the total of electrode cable length
(A) + work cable length (B) + work length (C) (See
Figure A.3).
FIGURE A.3
POWER
WAVE
B
For long work piece lengths, a sliding ground should
be considered to keep the total welding loop length
less than 15.24m). (See Figure A.4.)
50 ft.(
FIGURE A.4
FIGURE A.4
POWER
WAVE
K1796 COAXIAL CABLE
MEASURE FROM END
OF OUTER JACKET OF
CABLE
Output connections on some Power Waves
via 1/2-13 threaded output studs located beneath the
spring loaded output cover at the bottom of the case
front.
Most welding applications run with the electrode being
positive (+). For those applications, connect the elec-
trode cable between the wire feeder and the positive
(+) output stud on the power source (located beneath
the spring loaded output cover near the bottom of the
case front). Connect the other end of the electrode
cable to the wire drive feed plate. The electrode cable
lug must be against the feed plate. Be sure the con-
nection to the feed plate makes tight metal-to-metal
electrical contact. The electrode cable should be sized
according to the specifications given in the work cable
connections section. Connect a work lead from the
negative (-) power source output stud to the work
piece. The work piece connection must be firm and
secure, especially if pulse welding is planned.
INSTALLATION
15.24m), tradi-
50 ft.(
15.24m)), the K1796 Coaxial
A
C
WORK
A A
C WORK
C
B B
SLIDING WORK
® are made
POWER WAVE
For additional Safety information regarding the elec-
trode and work cable set-up, See the standard "SAFE-
TY INFORMATION" located in the front of the
Instruction Manuals.
CAUTION
Excessive voltage drops caused by poor work
piece connections often result in unsatisfactory
welding performance.
------------------------------------------------------------------------

NEGATIVE ELECTRODE POLARITY

When negative electrode polarity is required, such as
in some Innershield applications, switch the output
connections at the power source (electrode cable to
the negative (-) stud, and work cable to the positive (+)
stud).
When operating with electrode polarity negative the
"Electrode Sense Polarity" DIP switch must be set to
the "Negative" position on the Wire Drive Feed Head
PC Board. The default setting of the switch is positive
electrode polarity. Consult the Power Feed
manual for further details.

VOLTAGE SENSING

The best arc performance occurs when the Power
Waves have accurate data about the arc conditions.
®
Depending upon the process, inductance within the
electrode and work lead cables can influence the
apparent voltage at the studs of the welder. Voltage
sense leads improve the accuracy of the arc conditions
and can have a dramatic effect on performance.
Sense Lead Kits (K940-10, -25 or -50) are available for
this purpose.
CAUTION
If the voltage sensing is enabled but the sense
leads are missing, improperly connected, or if the
electrode polarity switch is improperly configured,
extremely high welding outputs may occur.
------------------------------------------------------------------------
The ELECTRODE sense lead (67) is built into the con-
trol cable, and is automatically enabled for all semi-
automatic processes. The WORK sense lead (21) con-
nects to the Power Wave
located underneath the output stud cover. By default
the WORK voltage is monitored at the output stud in
the POWER WAVE 455M. For more information on
®
the WORK sense lead (21), see "Work Voltage
Sensing" in the following paragraph.
All constant current processes sense the voltage at the
output studs of the POWER WAVE
455M
®
A-4
® instruction
at the four pin connector
®
-455M by default.
®