Lincoln Electric SVM175-A Welder User Manual


 
TROUBLESHOOTING & REPAIR
F-24 F-24
RANGER 305D
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CHOPPER MODULE CAPACITOR DISCHARGE PROCEDURE (continued)
FIGURE F.2 CHOPPER MODULE CAPACITOR TERMINAL DISCHARGE
INSULATED
GLOVES
INSULATED
PLIERS
B1B1
B2B2
B3B3
B4B4
B5B5
B6B6
TEST PROCEDURE
1. Turn the engine off.
2. Perform the Case Cover Removal proce-
dure.
NOTE: It is necessary to remove the fuel cap in
order to take the case cover off the machine.
Be sure the fuel cap is ON when discharging
the chopper module capacitors.
3. Locate the chopper module and capacitor
assembly on the inner machine baffle. See
Figure F.2 and the Wiring Diagram.
NEVER USE A SHORTING STRAP TO DIS-
CHARGE CAPACITORS. If the Lincoln rec-
ommended resistor, or an equivalent resistor is
used, the capacitors can be discharged by
holding the resistor with insulated pliers and
using the resistor terminals to bridge Chopper
Module terminals B1 to B2, and B4 to B5. DO
NOT TOUCH THE TERMINALS OR METAL
PARTS OF THE PLIERS WITH YOUR BARE
HANDS. Hold the resistor in place for about 10
seconds.
If another type of resistor is used, jumper
leads may need to be attached to the resis-
tor. The leads can then be used to connect
terminals B1 to B2, and B4 to B5.
4. Using the volt/ohmmeter, check the voltage
across B1 and B2, then B4 and B5. It
should be zero volts in both cases.