Possible Welding Defects - Telwin HF Serie Manuel D'instructions Et D'entretien

11.0 POSSIBLE WELDING DEFECTS

DEFECT
POROSITY
CRACKS
LIMITED
PENETRATION
HIGH SPRAYS
PROFILE DEFECTS
ARC INSTABILITY
ELECTRODE MELTS
OBLIQUELY
12.0 TROUBLE SHOOTING
INCONVENIENCE
No power ON
Unit and power light
are ON, fan doesn't
work
No output voltage
WRONG OUTPUT
CURRENT
CAUSES
Acid electrode on steel with high
sulphur content.
Electrode oscillates too much.
Workpieces are too far apart.
Workpiece being welded is cold.
Material to be welded is dirty (e.g.
oil, paints, rust, oxides).
Not enough current.
Low current.
High welding rate.
Reversed polarity.
Electrode inclined in position
opposite to its movement.
Electrode is too inclined.
Welding parameters are incorrect.
Pass rate is not related to opera-
ting parameters requirements.
Not enough current.
Electrode core is not centered.
Magnetic blow phenomenon.
CAUSE
Bad primary connection.
Power light is defective / Inverter
PCB is defective.
Something is obstructing the fan.
Fan is defective /Problems on fan
power supply.
Overheated unit, yellow LED on
Over-, Undervoltage protection
intervention, green LED off.
Overcurrent protection interven-
tion, yellow LED on.
Internal relay has failed.
Inverter PCB is defective.
Defective control potentiometer /
Control PCB.
Low primary power supply
voltage.
SUGGESTIONS
Use basic electrodes.
Move edges to be welded closer
together.
Move slowly at the beginning.
Lower welding current.
Cleaning workpieces before
welding is an essetial method of
achieving neat weld beads.
Make sure operating parameters
are regulated and improve prepa-
ration of workpieces.
Make appropriate corrections.
Follow basic and general welding
principles.
Check condition of electrode and
earth wire connection.
Replace electrode.
Connect two earth wires to opposi-
te sides of the workpiece.
REMEDY
Check primary connection.
Contact after sales service centre.
Remove obstruction from the fan.
Contact after sales service centre.
Wait for thermal cutout to be reset.
Check power line. Reset the unit
by turning it off and on after 20
seconds.
Reset the unit by turning it off and
on after some minutes. If the unit
doesn't revert working contact
after sales service centre.
Contact after sales service centre.
Contact after sales service centre.
Contact after sales service centre.
Check power line.
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