Weldkar WK MMA 4065 DC Gebrauchsanweisung Seite 18

4. SERVICE
ALL MAINTENANCE AND REPAIR WORK MAY ONLY BE CARRIED
OUT BY QUALIFIED PERSONS.
4.1 MAINTAINING THE LASER INVERTER
Check that the switch (12) is set to "On" and that the power cable
is disconnected from the mains when carrying out maintenance
in the unit.
Regularly clean the inside of the unit and remove the
accumulated metal dust with compressed air.
4.3 TROUBLESHOOTING AND SERVICE PROVISION
The power lamp lights up, the
fan is running normally, but
there is no welding current.
Hot welding clamp.
Large sparks occur during
welding.
4.2 ACTIONS TO BE CARRIED OUT AFTER A REPAIR
After a repair, check that the cabling has been installed
correctly and that there is sufficient insulation between the
primary and secondary sides of the machine. Make sure
that the wires do not come into contact with moving parts
or parts that get heated during operation. Reassemble all
clamping rings in the original way to prevent a connection
between the primary and secondary if a wire breaks or
comes off. Also reassemble the screws with the pliers in the
original way.
Check that the power switch is on.
Verify that the power cord is properly connected to the power supply.
The power supply is damaged and must be replaced.
Check the connections, such as those of the welding cables, for poor
connections.
Check all connections in the machine for good contact.
Check that one connection of the welding circuit is faulty.
Check that the alarm lamp is on.
(1) A safety device has been activated due to overheating, in which case the
voltage can be maintained so that the fan can cool down the unit to an
acceptable temperature. If the alarm lamp then goes out, welding can be
resumed.
(2) Check if the thermal safety device is damaged and replace it if necessary.
The welding clamp is too small for the current used, replace it with a larger one.
The polarity of the welding terminals is wrong, turn them over.