ESAB Digimig Dual Instruction Manual page 20

SECTION 4
If the speed servo cannot be adjusted at all, the
problem may be in the J-Governor, and/or I/O, and/or
MPU p.c. boards which need to be replaced as
required.
4. If a Voltage abort had occurred (VOLTS window
flashing), check and/or adjust the voltage (servo) as
follows:
This is a two man operation. Set a welding condition
which closely corresponds to your welding applica-
tion and the proper speed (ipm) for a given wire size
and then — close the torch switch and strike a
welding arc. While welding, actuate the Purge (Re-
set) switch position, and read the number displayed
in the VOLTS window, it may appear unsteady but
readable and should be 95.
If the number is not in the 90-100 range, use the Inc/
Dec toggle (below the VOLTS window) to adjust the
number to 95 — while "holding" the toggle positions
mentioned above and while welding.
5. If the voltage servo cannot be adjusted, check for
proper operation of the power source as follows:
a. Set the Digimig voltage display to zero (this setting
will override the servo).
20
TROUBLESHOOTING
b. Place the Panel/Remote switch on the power
source in PANEL position.
c. Make a weld by controlling the arc voltage directly
from the power source potentiometer.
d. If a weld can be made with good control over power
source voltage; a problem exists either in the inter-
connecting voltage control cable, or in the Digimig
control.
e. Check the control wires in the interconnecting
voltage control cable for continuity between the
appropriate terminals in the power source and
digimig using the schematic diagrams.
f. If continuity is correct, replace the I/O board and/
or the MPU board.
H. Control Shut-Down Due to Ground Fault Detec-
tion — both IPM and VOLTS displays will flash.
The purpose of this circuit is to make sure that welding
current is not present in the wire feeder frame/base,
control box, or the equipment safety ground. If this
should occur, the ground fault detector will temporarily
energize and immediately terminate the weld. This
abort is indicated by both visual displays flashing simul-
taneously. — Before attempting to make a new weld,
make sure that the Work Ground cable and its connec-
tions are properly and securely made to the workpiece.