Product Manual
07/02/11 M40CT_GB
PROBLEM ASSOCIATED SYMPTOMS POSSIBLE CAUSE VERIFICATIONS WHAT TO DO
P11 Lack of wel-
ding current
control
Full welding power (without
current control) regardless
of the knob position. When
the auto-idle is installed,
the machine remains at low
r.p.m.
Hall sensor failed In order to check the proper operation of the Hall sensor it is necessary to use specic
test and troubleshooting tools. Anyway, a visual inspection coul be enough to localise
possible damages, with particular reference to possible wear of the cable end coming
out of the Hall sensor potting. Please check also the connector contacts crimping at the
opposite end of the cable.
In case of evidence of damages consider the suggested action
Replace the Hall sensor
P12 Lack of wel-
ding current
control (ap-
plicable only
to CS 350)
Full welding power (without
current control) regardless
of the knob position
Chopper and/or driver
board failed
Disconnect the chopper cable from the connector J3 of the WAC. Check that the open
circuit voltage is < 1V. If not put a light resistive load at the welding output (few kohms
are enough) and check again the previous condition. If it is not satised the chopper is
faulty.
If a welding load bank and a clamp DC amp meter are available, another test can be
done to localise the failed section/s. To this purpose set the load bank for a current of
a few tens of amps and measure the current at the output of each chopper section (the
group of cables which connect the chopper to one end of the welding current leveling
reactor). The sections through which the current ows are failed or improperly driven
by the driver board. If the test conrms this type of failure consider the suggested cor-
rective action.
Replace the chopper and the
driver board
P13 Lack of wel-
ding current
control (ap-
plicable only
to CS 230)
Full welding power (without
current control) regardless
of the knob position
Chopper faulty Disconnect the chopper cable from the connector J3 of the WAC. Check that the open
circuit voltage is < 1V. If not put a light resistive load at the welding output (few kohms
are enough) and check again the previous condition. If it is not satised the chopper is
faulty.
In this case consider the suggested corrective action.
Replace the chopper
P14 Knob irregu-
lar or mis-
sing current
adjustment
When turning the knob the
current setting (and the vol-
tage setting, if applicable)
do not change or change
irregularly
The potentiometer which
regulates the welding
current (and the welding
voltage, when applica-
ble) is faulty
Check if the regulation through remote control works properly. If conrmed, consider the
suggested corrective action.
Replace the potentiometer
CS
M
40.3
REV.0-02/11
Trouble shooting