Weldmatic 200i + Weldmatic 250i
Model No CP137, CP138
25
Circuit breaker trips during welding
1 Check the rating of the mains supply
circuit breaker. The Weldmatic should be
supplied from a suitable circuit breaker
(refer to section 5).
Unsatisfactory Welding Performance
and Results
Erratic arc characteristics caused by poor
wirefeed
Erratic wirefeed is the MOST LIKELY cause of
failure in all Gas Metal Arc Welding. It should
therefore be the first point checked when
problems occur.
1 Refer to the points in ‘Wirefeed’ in Section 5
2 Check if the consumable wire is slipping
in the drive rolls. Replace the feed roll if
it is the incorrect size or is worn
3 Check that gun cable liner is not too
short and is fitted correctly. Refer to
page 28 for fitting instructions.
Constant poor arc characteristics
Check that the:
1 Correct polarity has been selected for
work and weld cables (refer page 10)
2 Shielding gas is correct for the
consumable wire in use (refer page 14)
3 Welding circuit is making good electrical
connection. Ensure that the work clamp
is securely tightened onto the work piece
so that good electrical contact is achieved
4 All connections in the external welding
circuit are clean and tight. Problems may
show as hot spots
5 Work piece surface is not contaminated.
Water, oil, grease, galvanising, paint,
or oxide layers can severely disturb the
welding arc and result in a poor weld.
Porosity in weld caused by lack of
shielding gas
1 Check that the correct gas flow rate has
been set (refer page 14)
2 Check for leaks in the gas hose. Replace
if leaking
3 Check for leaks in gun/cable assembly,
eg. fractured gas hose, broken or missing
‘O’ rings. Replace as required
4 Check the gun nozzle is free from spatter
and is firmly attached to the welding gun
to ensure that no air is being drawn into
the shielded area.
