MAINTENANCE | ||
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SAFETY PRECAUTIONS
WARNING
ELECTRIC SHOCK can kill.
•Only qualified personnel should perform this maintenance.
•Turn the input power OFF at the disconnect switch or fuse box before working on this equipment.
•Do not touch electrically hot parts.
WARNING
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 Precision TIG 275 running in top condition. No specific schedule can be set for performing the follow- ing items; factors such as hours of usage and machine environment should be considered when establishing a maintenance schedule.
•Periodically blow out dust and dirt which may accu- mulate within the welder using an air stream.
•Inspect welder output and control cables for fraying, cuts, and bare spots.
•Inspect the spark gap at regular intervals to maintain the recommended spacing. See the Service Procedures (See Service Procedures in this Section) for complete information on spark gap set- tings.
•The fan motor has sealed ball bearings which require no maintenance.
Overload Protection
OVERLOAD PROTECTION
FAN-AS-NEEDED (F.A.N.)
The Precision TIG 275 has the F.A.N. circuit feature, which means the cooling fan will operate only while welding; then for about 8 minutes after welding has stopped to assure proper machine cooling. This helps reduce the amount of dust and dirt drawn into the machine with the cooling air. The cooling fan will oper- ate briefly when the machine power is initially turned on, and continuously while the yellow Thermal Shutdown Light is lit (see Thermostatic Protection).
THERMOSTATIC PROTECTION
This welder has thermostatic protection from excessive duty cycles, overloads, loss of cooling, and excessive ambient temperatures. When the welder is subjected to an overload, or inadequate cooling, the primary coil thermostat and/or secondary coil thermostat will open. This condition will be indicated by the illumination of the yellow Thermal Shutdown Light on the front panel (see Item 10 in Section B). The fan will continue to run to cool the power source. Postflow occurs when TIG welding is shut down, but no welding is possible until the machine is allowed to cool and the yellow Thermal Shutdown Light goes out.
NO ARC PROTECTION
The machine outputs (Background / OCV, gas and HF) will be shutdown, if the trigger is closed without weld- ing for 15 seconds to protect the Background resistor from overheating with F.A.N. cooling off, as well as to conserve on gas waste.
AUXILIARY POWER CIRCUIT BREAKER
The 115vac auxiliary circuits and rear receptacle (see Section A Auxiliary Power Connections) are protected from overloads by a 15 amp circuit breaker, located above the receptacle. If the breaker trips its button pops out exposing a red ring. When the circuit breaker cools the button can be reset by pressing it back in.
Note: When the breaker trips not only will the recepta- cle’s auxiliary and cooler power be interrupted, but so will the power to the shielding gas solenoid and machine cooling fan.
The Export models also include a 5 amp circuit break- er, located on the opposite side of the upper case back, for protection of the 220vac Schuko type cooler recep- tacle.
