Lincoln Electric WIRE FEED MODULE IM 513-B - Manual (Page 24)

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3. Check to see that leads 2 and 4 are con-
nected. Put a voltmeter across these
leads and the meter should read close to
zero volts. If voltage reads approximately
15 volts, then the trigger circuit (leads 2-4)
is open. Check the wiring from the WFM
control box to the WFM control panel for
loose or broken connections. Turn
machine off and check the operation of
the “LOCAL/REMOTE” switch by connect-
ing an ohmmeter across leads 2 and 4 at
the switch with switch positioned in
“LOCAL” mode, if resistance is high or
open replace the switch.
4. Check for coil voltage across leads 633
and 634 at P2 plug to the P.C. Board. If
voltage is present, check for loose or bro-
ken leads from the plug to the contactor
coil. If connections are good and voltage
correct, replace contactor CR4.
5. If no voltage is present at CR4 contactor
coil, see Procedure for Replacing P.C.
Boards.
E. Procedure for Checking the Capacitor
Bank Contactor (CR3)
1. Verify machine is in CV (wire) mode.
Measure voltage across leads 630 and
631 at the contactor. The voltage should
be approximately 120 +/- 15V DC with
engine set on high idle. If voltage is not
present, go to step 3 of this procedure.
2. If the proper voltage is present at leads
630 - 631, measure the voltage between
L2 terminal and terminal opposite L2. If
the voltage is equal to the output voltage
across the positive and negative output
terminals, replace the contactor CR3.
3. If the proper voltage is not present at
leads 630 - 631, check the wiring to CR3
coil for loose or broken connections. If
connections are good, see Procedure for
Replacing P.C. Boards.
F. Checking Voltage Control Potentiometer
on Machine
1. Turn machine off.
2. Remove the control panel screws and
open the front cover. Turn the
“LOCAL/REMOTE” switch (S2) to
“REMOTE”.
3. Disconnect P.C. Board harness plug P2
from the P.C. Board.
4. With an ohmmeter on X1K, connect it to
lead 76A and 77A on S2. Rotate the volt-
age control potentiometer. The resistance
reading should be from approximately
zero to 10K ohms. Check the resistance
reading between lead 75 on potentiometer
and 77A on switch S2. The reading must
be 10K ohms. No reading will indicate an
open potentiometer and a low reading will
indicate a shorted or partially shorted
potentiometer; in either case, replace.
Reconnect P.C. Board plug P2.
G. Remote Control Check
1. The remote control connector pin assign-
ments are: pin G-75A, pin F-76B, pin E-
77B. Make sure remote control connec-
tions are tight and check for any physical
damage to the control cable. Connect an
ohmmeter across lead 75 and 76B on
switch S2. With S2 in remote mode,
rotate the potentiometer in the remote
control. The resistance reading should
vary from zero to 10K ohms. Repeat with
ohmmeter across 77B and 76B with the
same results. Connect an ohmmeter
across 75 and 77B. The reading should
be 10K ohms. If an open or short is mea-
sured replace the potentiometer.