Product Manual
07/02/11 M40CT_GB
PROBLEM ASSOCIATED SYMPTOMS POSSIBLE CAUSE VERIFICATIONS WHAT TO DO
P6 Lack of voltage
control in CV mode
(applicable to the
CC-CV machines
provided with lter
board)
The open circuit voltage in
CV mode is the same as for
the CC mode, regardless of
the control knob position
Failure in the EMC lter
board on the welding so-
ckets
Check by means of a multimeter (stopped machine) the resistence value between
positive welding socket and the corresponding faston connector on the lter board.
The condition to check is:
ohmic value between + welding socket and + board faston (the one to which the red
cables are connected) < 4 ohm
In case of condition not satised take the indicated corrective action.
Replace the EMC lter board
P7 No welding arc
(applicable to the
machines provided
with the lter board
on the welding so-
ckets)
The open circuit voltage is
zero
Failure in the EMC lter
board on the welding so-
ckets
Check by means of a multimeter (stopped machine) the resistence value between
positive welding socket and the corresponding faston connector on the lter board.
The condition to check is:
ohmic value between - welding socket and - board faston (the one to which the black
cables are connected) < 4 ohm
In case of condition not satised take the indicated corrective action.
Replace the EMC lter board
P8 Minimum welding
current in CC mode
too high (applicable
to the machines
provided with the
lter board on the
welding sockets)
The welding current in CC
mode with the knob at be-
ginning of scale is too high
and changes when turning
the arc force knob (if pre-
sent, switch in ON position)
Failure in the EMC lter
board on the welding so-
ckets
Check by means of a multimeter (stopped machine) the resistence value between
positive welding socket and the corresponding faston connector on the lter board.
The condition to check is:
ohmic value between + welding socket and + board faston (the one to which the red
cables are connected) < 4 ohm
In case of condition not satised take the indicated corrective action.
Replace the EMC lter board
P9 Minimum welding
current in CC mode
too high
The welding current in CC
mode with the knob at be-
ginning of scale is too high
and changes when turning
the arc force knob (if pre-
sent, switch in ON position)
Cable interruption betwe-
en the WAC or the wel-
ding control board (as
applicable depending on
the machine type) and
the welding sockets
With the machine stopped, extract the connector plugged to J1 of the WAC / Wel-
ding control board (as applicable depending on the machine type). Check by means
of a multimeter the continuity between pin 6 of the connector and the positive wel-
ding socket. The resistive value shall be < 4 ohm if there is a lter board behind the
sockets, otherwise shall be < 0.5 ohm.
In case of condition not satised take the indicated corrective action.
Fix the cabling or replace it.
P10 No welding arc The open circuit voltage is
zero
Cable interruption betwe-
en the WAC or the wel-
ding control board (as
applicable depending on
the machine type) and
the welding sockets
With the machine stopped, extract the connector plugged to J1 of the WAC / Wel-
ding control board (as applicable depending on the machine type). Check by means
of a multimeter the continuity between pin 5 of the connector and the negative wel-
ding socket. The resistive value shall be < 4 ohm if there is a lter board behind the
sockets, otherwise shall be < 0.5 ohm.
In case of condition not satised take the indicated corrective action
Fix the cabling or replace it.
CS
M
40.2
REV.0-02/11
Trouble shooting