Lincoln Electric INVERTEC V275-S Service Manual page 37

F-7
Observe Safety Guidelines
detailed in the beginning of this manual.
FUNCTION PROBLEMS
(SYMPTOMS)
The machine regularly overheats
and the yellow thermal light is ON
indicating a thermal overload.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.
Call 1-888-935-3877.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS
1. The welding application may be
exceeding the recommended
duty cycle of the V275-S.
2. Dirt and dust may have clogged
the cooling channels inside the
machine.
3. The air intake and exhaust lou-
vers may be blocked due to
inadequate clearance around
the machine.
4. Make certain the fan as needed
(F.A.N.) circuit is operating prop-
erly. The fan should operate
when 15 amps of welding cur-
rent is present and/or when
there is an over temperature
condition. When the machine is
turned on the fans should oper-
ate for approximately 3 sec-
onds.
CAUTION
V275-S
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. The 230 VAC fan motors are
controlled by the control board
via the fan relay (CR1). Perform
the Fan Motors and Control
Test.
2. One of the thermostats or asso-
ciated circuitry may be faulty.
One normally closed thermostat
is located on the output choke,
another is on the main switch
board heat sink and the third
thermostat is mounted on the
output rectifier heat sink. See
the wiring diagram.
Note: The Main Switch Board
Removal Procedure will be
required to gain access to
the thermostat located on
the main switch board heat
sink.
F-7