Lincoln Electric LN-23P Service Manual page 45

F-17
TEST PROCEDURE
1. Connect a switched and grounded 120VAC supply
to terminals 31 & 32 of the Control Terminal Strip
and the ground stud (GND) as shown in Fig. F.5.
2. Connect two toggle or push button switches to ter-
minals 602 & 604 of the Wire Feed Tereminal strips.
WARNING
ELECTRIC SHOCK can kill.
• Only qualified personnel should perform this
installation, maintenance and troubleshooting
work.
• Turn off the input power at the fuse box before
working on other equipment connected to the
welding system at the disconnect switch or fuse
box before working on this equipment.
• Do not touch electrically hot parts.
MEASUREMENT POINTS
CONTROL WIRE FEED
TERMINAL TERMINAL
STRIP STRIP
21 521A
521B
75 75A
75B
76 76A
76B
77 77A
77B
4 to 2A
4 to 2B
TROUBLESHOOTING AND REPAIR
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K350(-1) ADAPTER TEST (cont.)
FIGURE F.7 TROUBLESHOOTING CHART
SWITCH
A & B
OPEN
OPEN (∞) SHORT (0Ω) OPEN (∞)
OPEN (∞)
OPEN (∞) SHORT (0Ω) OPEN (∞)
SHORT (0Ω)
OPEN (∞) SHORT (0Ω) OPEN (∞)
SHORT (0Ω)
SHORT (0Ω) SHORT (0Ω) SHORT (0Ω)
SHORT (0Ω) SHORT (0Ω) SHORT (0Ω)
---- OPEN (∞) SHORT (0Ω) OPEN (∞)
---- OPEN (∞)
3. Close the Power Switch (S1).
4. Check for 24VAC at terminals 605 &606 on the PC
Board.
If no voltage or incorrect voltage, check the
Control Transformer.
5. With an Ohmmeter or continuity tester, check for the
values listed in the troubleshooting chart (Fig.F.7),
under all three conditions, (Switch A&B open,
Switch A closed and Switch B closed).
6. When Switch A is closed, 1CR relay should function.
When Switch B is closed, 2CR relay should func-
tion.
a. If neither relay functions the PC Board may
be defective.
b. If one of the relays does not work, check for
24vdc at the relay coil. (See Wiring
Diagram).
If voltage is present, replace the relay.
If no voltage, check the wiring.
7. If all of the above tests are correct, check the
Control Cable for continuity on all leads. (See the
Wiring Diagram)
EXPECTED READING
SWITCH A SWITCH B
CLOSED CLOSED
B OPEN A OPEN
OPEN (∞) SHORT (0Ω) 2CR or PC Bd
OPEN (∞) SHORT (0Ω) 2CR or PC Bd.
OPEN (∞) SHORT (0Ω) 2CR or PC Bd.
OPEN (∞) SHORT (0Ω) 2CR or PC Bd.
LN-23P
INCORRECT
CORRECTIVE
READING
ACTION
INDICATES
1CR or PC Bd
Perform
1CR or PC Bd.
tests in
Step 6
1CR or PC Bd.
Check for loose
Wiring
or broken con-
Wiring
nections
Perform
1CR or PC Bd.
tests in
Step 6
F-17