Repair Service - Praxair MICROTIG 161 Mode D'emploi

7. MAINTENANCE
This arc welding equipment should be routinely maintained according to the manufacturers' recommendations. All access and
service doors and covers should be closed and properly fastened when the arc welding equipment is in operation. The arc
welding equipment should not be modified in any way, except for those changes and adjustments covered in the manufacturer's
instructions. In particular, the spark gaps of arc striking and stabilizing devices should be adjusted and maintained according to
the manufacturer's recommendations.
Before carrying out any internal checking or repair work, check that the power source has been disconnected from the electrical
installation by locking and guard devices. Ensure and avoid accidental connection of the plug to a socket. Voltages are high and
dangerous inside the machine.
Despite of their robustness, power sources require some regular maintenance. Each 6 months or more often in dusty
surroundings:
- The machine must be blown through with dry, oil free compressed air.
- Check for continuity all electrical connections.
- Check the connection of cables and flat top.
Check the good state, insulation and connection of all the equipment and electrical accessories: plugs and flexible supply cables,
conduits, connectors, extension cables, sockets on the power source, ground clamp and electrode holder. These connections
and mobile accessories are marked according to standards, if consistent with the safety rules. They can either be controlled by
you or by accredited firms.
-Repair or replace all defective accessories
-Check periodically that the electrical connections are tightened and do not heat.
Maintenance works of electrical equipment must be entrusted by qualified people (Section VI, Art. 46).
7.1 – REPAIR SERVICE
POSSIBLE CAUSES
DISPLAY OFF = NO SUPPLY
ON/OFF main switch is OFF
Power supply cable is cut
No main supply
Defective ON/OFF main switch
THERMAL INDICATOR ON = INPUT VOLTAGE OVER RATED LIMIT
Input voltage > 265V
Power source connected to 2 phases
Duty cycle over rated (if ambient > 25°C)
Insufficient cooling air
Very dusty machine
Fan doesn't start
IMPROPER WELDING
Wrong electrode polarity
Dirtiness in the weld parts
CHECK
Switch it ON
Check cable and connections
Check circuit breaker and fuses
Replace the switch
Check supply voltage
Connect the machine to proper voltage (230V)
Let the machine cool, it will automatically start again
Clean the air inlets
Open the generator and blow it through
Replace the fan
Use the right polarity according to the indications of
electrode's manufacturer
Clean and eventually degrease the weld parts
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