Lincoln Electric IDEALARC CV-250 - Manual (Page 27)

E-8 TROUBLESHOOTING E-8
CV-250
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
OUTPUT VOLTAGE
The open circuit voltage of the machine should be 10
to 43 volts. If any other condition exists, refer to the
Troubleshooting Guide.
FAULT PROTECTION OPERATION
The overload protection circuit on the PC Board will
cause the CV-250 meter to display "E60". This pro-
tection circuit will reset itself automatically. The short
circuit protection circuit will cause the meter to display
"E00". The CV-250 power switch must be turned
"OFF" and then "ON" to return the machine to normal
output.
CHECKING SNUBBER CIRCUIT
In case of an SCR malfunction or failure, the snubber
assembly should be checked. Disconnect the input
power to the CV-250 at the fuse box and remove the
right side of the machine.
1.Visually inspect the snubber PC Board assembly
(located below the Control PC board on the case front
for overheated components or damaged compo-
nents).
OPTIONAL K857 REMOTE CONTROL
CHECK
Disconnect the remote output control and connect an ohm-
meter between pins C and B and rotate the rheostat in the
remote control. The resistance reading should go from zero
to 10K ohms. Repeat with ohmmeter across A and B with
the same results. Connect ohmmeter across A and C. The
reading should be 10K ohms. A lower reading will indicate a
shorted or partially shorted rheostat. A very high reading
will indicate an open rheostat. In either of the last two
cases, replace the rheostat.