SAFETY PRECAUTIONS
ELECTRIC SHOCK can kill.
• Only qualified personnel should per-
form this maintenance.
• Turn the input power OFF at the dis-
connect switch or fuse box before
working on this equipment.
•
Do not touch electrically hot parts.
To avoid receiving a high frequency shock, keep the
TIG torch and cables in good condition.
ROUTINE AND PERIODIC
MAINTENANCE
Very little routine maintenance is necessary to keep
your Square Wave TIG 275 running in top condition.
No specific schedule can be set for performing the fol-
lowing items; factors such as hours of usage and
machine environment should be considered when
establishing a maintenance schedule.
1.
Periodically blow out dust and dirt which may accu-
mulate within the welder using an air stream.
2.
Inspect welder output and control cables for fray-
ing, cuts, and bare spots.
3.
Inspect the spark gap at regular intervals to main-
tain the recommended spacing. See the Service
Procedures Section for complete information on
spark gap settings.
4.
The fan motor has sealed ball bearings which
require no maintenance.
OVERLOAD PROTECTION
This welder has thermostatic protection from excessive
duty cycles, overloads, loss of cooling, and high ambi-
ent temperatures. When the welder is subjected to an
overload or loss of cooling, a thermostat will open.
This condition will be indicated by the illumination of
the yellow Thermostatic Protection Light on the case
front . The fan will continue to run to cool the power
source. No welding is possible until the machine is
allowed to cool and the Thermostatic Protection Light
goes out.
FAN AS NEEDED (F.A.N.)
The Square Wave TIG 275 has the F.A.N. circuit fea-
ture, which means the cooling fan will operate only
while welding, then for about 6 minutes after welding
has stopped. The cooling fan will operate conintuous-
ly if the yellow Thermstatic Protection Light in “ON.”
SERVICE PROCEDURES
Use extreme caution when working with the secondary
circuit of the high frequency transformer. Turn the input
power off using the disconnect switch or fuse box
before working inside the machine. This is particularly
important when working on the secondary circuit of the
high voltage transformer (T3) because the output volt-
age is dangerously high.
DO NOT APPLY POWER TO THE SQUARE WAVE
TIG 275 WITH THE SIDES AND ROOF REMOVED.
The case front and case back assemblies tend to lean
in towards the center assembly; there is a danger of a
short circuit when this occurs. If you must troubleshoot
the machine with power applied, do so with the roof in
place, and check for shorts before applying power.
Operation of the Square Wave TIG 275 should be trou-
ble-free for the life of the machine. Should a malfunc-
tion occur, however, the following procedures will be
useful to trained service personnel with experience in
repairing arc welding equipment.
MAINTENANCE
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SQUARE WAVE TIG 275
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WARNING
WARNING
WARNING
