Lincoln Electric INVERTEC V275-S Service Manual page 68

F-38
FAN CONTROL AND MOTOR TEST (continued)
TEST PROCEDURE
1. Using a 5/16" nut driver, remove the case wrap-
around cover.
2. Run a jumper at the control board from 382 on
plug J2 to R222 on plug J4. See Figure F.18.
NOTE: The fan motor should run. This step ener-
gizes the CR1 fan relay.
applies 230VAC to the two fans. Make
sure both fans are running.
3. Perform the Input Filter Discharge Procedure
detailed earlier in this section.
4. Locate the thermostat on the output diode
module heatsink. See Figure F.16.
NOTE: This step will imitate an overheated condi-
tion and should prompt the fan motors to
run when the input power is applied. If the
fan motors operate normally, the fan
motors and the fan relay are functioning
correctly. If the fan motors do not operate,
continue to the next step. If the fan motors
operate during an over heated condition
but do not operate when a minimum of 15
amps is drawn from the output terminals,
the control board may be faulty.
TROUBLESHOOTING AND REPAIR
CR1 contact
FIGURE F.16 - Thermostat Location
Thermostat
5. Locate plug J2 leads 383+ and 382- on the
control board. See Figures F.17 & F.18.
6. With the thermostat lead still removed check
for approximately 10-12VDC from lead 383+ to
lead 382-. If this voltage is correct, remove the
input power. If this voltage is not present, the
control board may be faulty. Remove the input
power. See Figure F.18.
7. Remove plug J2 from the control board and
check the resistance of the fan relay coil.
Normal resistance is approximately 82 ohms. If
the coil resistance is very low, the coil may be
shorted. If the resistance is very high or infinite,
the coil of associated leads may be faulty. See
the Wiring Diagram. See Figure F.17.
8. If the coil resistance is normal, the fan relay
contacts may be faulty or the fan motors may
be faulty. Make sure that 230VAC is being
applied to the fan motors.
Diagram.
9. Replace the thermostat lead previously
removed.
10. Replace Plug J2.
11. Replace the case wraparound cover.
380V
208-230V
V275-S
F-38
See the Wiring