TM
5-3431-200-15
rendition exists, the following expedient re-
47. Welder Will Not Operate When Power
pairs may be used in emergencies, upon the de-
Switch Is placed in the ON Position
cision of the unit commander. Equipment so
Expedient remedy
Trouble
repaired must be removed from operation as
Power switch defective ---- Remove the switch (par.
soon as possible and properly repaired before
being placed in operation again.
together and operate
the welding set with-
out the switch.
46. Wire Fails to Feed When Inching
Note. Disconnect the control cable from the welder
Switch Is Pressed
before performing the field expedient repair above.
Expedient remedy
Trouble
Warning: Performing any field expedient
Inching switch
Feed the welding wire
repair creates a condition possibly dangerous to
through the gun by hand
defective.
personnel or equipment. A welding set so re-
and operate the set
paired should be taken out of service as soon
without the inching
as possible for replacement of defective parts.
switch (par. 88).
Section VI. ARGON GAS SYSTEM
(2) Inspect the hose for cracks, kinks,
48. General
and breaks and the pipe for cracks and
The components of the welding set argon
worn or stripped threads. Replace as
gas system are a gas regulator which can be ad-
required. Inspect the solenoid valve
justed to deliver the cubic feet of gas per hour
for broken or frayed electrical leads,
as needed, and which also registers the pres-
corrosion, and signs of deterioration.
sure of the gas cylinder; a 10-foot hose connect-
Replace if necessary.
ing the regulator and the control assembly ; an
c. Testing. Test the solenoid valve as fol-
electrically operated gas solenoid valve located
lows:
inside the control assembly; two short lengths
(1) Use a multimeter set on RX1OO ohm
of metal pipe extending from the solenoid
scale. Touch the probes of the multi-
valve to the front and rear of the control as-
meter to the solenoid leads.
sembly; a 50-foot hose connecting the welding
(2) The ohm scale should read 1,950
gun to the control assembly, and the necessary
ohms 5 percent.
fittings required to connect the system.
(3) Replace the solenoid valve if it does
not meet this test requirement.
49. Hose Assembly, Solenoid Valve, and
(4) Apply air pressure to the inlet port
Gas Pipe
of the valve and check for leaks
a. Removal.
through the valve by using a soap and
(1) Refer to paragraph 10 and remove
water solution on the outlet port. The
the gas regulator.
presence of bubbles indicates an inter-
(2) Refer to figure 11 and remove the
nal leak and the valve must be re-
hose assembly, solenoid valve, and
placed.
gas pipe.
d. Installation.
b. Cleaning and Inspection.
(1) Refer to figure 11 and install the
(1) Clean the hose and gas pipe with a
hose assembly, solenoid valve, and
cloth dampened with an approved
gas pipe.
solvent.
Clean the solenoid valve
with a dry, lint-free cloth or dry Com-
(2) Refer to paragraph 10 and install the
pressed air.
gas regulator.
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