25
SC1900
Troubleshooting
Problem
Possible
Cause
Fix
Unit
stops
welding,
OverTemp
LED
is
on.
Over
heating.
1.
If
the
fan
is
running,
allow
unit
to
cool.
2.
Slow
down
welding
rate
(fewer
studs
per
minute).
3.
Any
fault
in
the
OverTemp
Thermostat
Circuit
will
shut
the
system
down.
Weld
output
erratic
or
weak.
Adjustments
or
set
‐
tings.
1.
Check
welding
hand
tool
set
up,
lift,
plunge,
and
acces
‐
sory
adjustments.
2.
Check
ALL
weld
current
carry
leads
and
connections,
in
‐
cluding
grounds.
3.
Test
the
power
loop
by
making
welds
on
a
test
piece
us
‐
ing
only
the
starter
cable
set.
4.
Test
3
phase
power
to
control
contactor.
5.
Check
taps
(if
applicable)
on
main
transformer.
Weld
gun
lifts,
but
does
not
plunge.
Gun
maintenance.
If
this
happens,
it
is
most
likely
binding
inside
of
the
gun.
Per
‐
form
routine
gun
maintenance
or
replace
gun
if
needed.
All
tests
should
be
performed
by
a
qualified
person.
Always
turn
off
power
to
the
welder
before
working
on
or
testing
components
within
the
welder.
Contact
your
TRU
‐
WELD
Equipment
Representative
for
replacement
parts
and
for
servicing
your
welding
equipment.
