IMA 574B
CV320-I
Page 11
Possible Cause
Defective wire feed motor or wire drive
control PC board.
Defective wire drive control PC board.
Over-temperature protection circuit
actuated due to overload or short. Over-
temperature light should be illuminated.
Faulty gun trigger switch or damaged
control cable connected to gun trigger.
Defective control PC board.
Defective contactor.
Improper settings for wire feed speed and
volts.
Faulty rotary switch either coarse control
(on/off) or fine control.
Faulty pilot transformer.
Faulty main transformer.
Faulty rectifier.
Faulty choke.
What To Do
Measure the voltage between Red motor lead
(54) and the Green motor lead (53) when the
wire inch push button is depressed. If this
voltage is over 10V DC, replace the wire feed
motor. If no voltage is registered, replace the
wire drive PCB. (Refer PCB replacement
procedure at end of Trouble Shooting Guide).
Replace PCB. (Refer PCB replacement
procedure at end of Trouble Shooting Guide).
Allow machine to cool down and reduce on
time and/or wire feed speed.
Repair.
Refer Procedure for Replacing PC Boards at
end of Trouble Shooting Guide, if no fault is
detected in trigger-thermostat circuit.
Replace defective contactor.
Set controls correctly.
Replace rotary switch.
Replace.
Replace.
Replace.
Replace.
Problem
No wire feed, although arc
voltage is present.
No control of wire feed.
No wire feed and no arc voltage.
Pilot light indicates input power to
machine.
Poor welding characteristics
and/or cannot obtain full rated
output as per nameplate.
Also see the LN21 wire feeder instruction manual
Note: This procedure is for ‘machines as built’ many modifications
could have taken place over the life of a particular machine, so
details of this procedure may need to be ‘adjusted’ to suit these
modifications.
For prompt service contact your local Lincoln Field Service Shop.
The insulation resistance values listed below are from Australian
Standard AS1966.1.
1)
Disconnect input cable from power outlet.
2)
Disconnect all output cables (control & weld).
3)
Remove the roof panel.
4)
Jumper the three (3) AC terminals and the (+) & (-) terminals
of the thre phase bridge rectifier (A total of five (5) places).
5)
Jumper the four (4) meter terminals together.
6)
Switch the fine control rotary switch to position one (1) &
switch the coarse control rotary switch to position
one (1).
7)
Primary test: Connect one lead of the mega tester to the
frame of the machine and the other lead to each of the three
(3) input conductors and to the main transformer primary
leads L1A, L2A & L3A. Apply the test(s).
8)
Welding circuit test: Connect one lead of the mega tester to
the frame of the machine and the other lead to the positive
output stud. Apply the test. (Min resistance 1M
Ω
).
9)
Welding circuit to primary test: Connect one lead of the
mega tester to the positive output stud and the other lead to
each of the three (3) input conductors and to the main
transformer primary leads L1A, L2A & L3A. Apply the test.
(Min resistance 10M
Ω
).
10) Transformer thermostat test: Connect one lead of the mega
tester to the frame of the machine and the other lead to the
positive output stud. Apply the test.(Min resistance 1M
Ω
).
11) Remove all jumper leads.
12) Refit the roof panel.
ELECTRIC SHOCK
can kill
GROUND TEST PROCEDURE FOR CV320-I
WARNING
If any problems are encountered, refer to your nearest Lincoln Field Service Shop.
TROUBLESHOOTING GUIDE (cont)
This procedure is only suitable for applications using DC
mega testers up to 500V.