Tweco 350 4R Wirefeeder - Manual (Page 50)

7-6 Manual 0-5182
weldskill 250, 350 service
Service
7 Weld cracking A
B
C
D
E
Weld beads too small
Weld penetration narrow and
deep
Excessive weld stresses
Excessive voltage
Cooling rate too fast
A
B
C
D
E
Decrease torch travel speed
Reduce current and voltage and
increase the MIG Torch travel
speed or select a lower penetration
shielding gas.
Increase weld metal strength or
revise design
Decrease voltage by reducing the
Voltage Control switches.
Slow the cooling rate by preheating
part to be welded or cool slowly.
8 Cold weld puddle A
B
C
D
Faulty rectifier unit
Loss of a phase in the Mains
supply voltage.
Loose welding cable connection.
Low Mains supply voltage
A
B
C
D
Have an Accredited CIGWELD
Service Provider test then replace
the faulty component.
Check mains power
Check all welding cable connections.
Contact supply authority
7.08 Power Source / Wirefeeder Problems
FAULT CAUSE REMEDY
1 Mains supply voltage
is ON. Indicator light
is not lit and welding
arc can not be
established.
A
B
Primary fuse is blown.
Broken connection in primary
circuit.
A
B
Replace primary fuse.
Have an Accredited CIGWELD
Service Provider check primary
circuit.
2 Mains indicator
light is not lit but
welding arc can be
established.
Burnt out Indicator light. Have an Accredited CIGWELD
Service Provider replace Indicator
light.
3 Mains supply
voltage is ON and
power Indicator
is lit however unit
will not commence
welding when the
torch trigger switch is
depressed.
A
B
Faulty torch trigger
Circuit breaker tripped
A
B
Repair or replace torch trigger
switch/leads
Reset Circuit Breaker(s)
4 Mains supply voltage
is ON, no wire feed
but gas flows from
the MIG Torch when
the torch trigger
switch is depressed.
A
B
Electrode wire stuck in conduit
liner or contact tip (burn-back
jam).
Faulty control PCB
A
B
Check for clogged / kinked MIG
Torch conduit liner or worn
contract tip. Replace faulty
components.
Have an Accredited CIGWELD
Service Provider investigate the
fault.