Tweco 1000 Merlin(Sept1999) - Manual (Page 41)

Manual 0-2731 37 SERVICE
5.03 Common Operating Faults
Listed below are common cutting problems followed by
probable causes of each. If the problems are caused by a
torch problem, refer to the appropriate Torch Manual.
1. Insufficient Penetration
a. Cutting speed too fast
b. Torch tilted too much
c. Incorrect Gas Settings
d. Metal too thick
e. Worn torch parts
f. Cutting current too low
g. Non-Genuine Thermal Dynamics Parts
2. Main Arc Extinguishes
a. Cutting speed too slow
b. Torch standoff too high from workpiece
c. Cutting current too high
d. Work cable disconnected
e. Worn torch parts
f. Non-Genuine Thermal Dynamics Parts
3. Excessive Dross Formation
a. Cutting speed too slow
b. Torch standoff too high from workpiece
c. Worn torch parts
d. Improper cutting current
e. Improper gas selection or settings
f. Non-Genuine Thermal Dynamics Parts
4. Short Torch Parts Life
a. Oil or moisture in gas source
b. Exceeding system capability (material too thick)
c. Excessive pilot arc time
d. Starting or finishing off the workpiece
e. Gas flow too low (incorrect pressure or flow setting)
f. Improperly assembled torch
g. Output current too high for parts being used
h. Torch tip contacting workpiece
i. Improper gas selection for parts being used
j. Damaged or loose torch head components
k. Restricted coolant flow
l. Non-Genuine Thermal Dynamics Parts
5. Poor Pilot Starting
a. Non-Genuine Thermal Dynamics Parts
b. High coolant conductivity
5.04 Common Operating Problems
WARNINGS
Disconnect primary power at the source before dis-
assembling the power supply, torch, or torch leads.
Frequently review the Important Safety Precau-
tions (page 1). Be sure the operator is equipped with
proper gloves, clothing, eye and ear protection.
Make sure no part of the operator’s body comes into
contact with the workpiece while the torch is acti-
vated.
CAUTION
Sparks from the cutting process can cause damage
to coated, painted, and other surfaces such as glass,
plastic and metal.
NOTE
Handle torch leads with care and protect them from
damage.
A. Piloting
Piloting is harder on parts life than actual cutting because
the pilot arc is directed from the electrode to the tip rather
than to a workpiece. Whenever possible, avoid excessive
pilot arc time to improve parts life.
B. Torch Standoff
Improper standoff (the distance between the torch tip and
workpiece) can adversely affect tip life as well as shield
cup life. Standoff may also significantly affect the bevel
angle. Reducing standoff will generally result in a more
square cut.
C. Edge Starting
For edge starts, hold the torch perpendicular to the work-
piece with the front of the tip at the edge of the work-
piece at the point where the cut is to start. When starting
at the edge of the plate, do not pause at the edge and
force the arc to "reach" for the edge of the metal. Estab-
lish the cutting arc as quickly as possible.