Maintenance; Troubleshooting - Praxair MICROTIG AC/DC 202 PULSE Guide De L'utilisateur

9. 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 stabilising
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 their robustness, ours power sources require some regular maintenance. Each 6 months (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).
9.1 – TROUBLESHOOTING
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
Duty cycle over rated
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
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
MICROTIG AC/DC 202 PULSE
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