Tweco Maximizer 300 Torch for BNFL - Manual (Page 32)

SERVICE 5-2 Manual 0-2990
2. Using an ohmmeter (set to 10K or higher), check
for continuity between the positive and negative
torch fittings. Infinite resistance (no continuity)
should be found. If continuity is found, refer to
Section 5.07, Torch and Leads Troubleshooting.
C. Torch O-ring Lubrication
The internal o-rings on the torch head assembly (elec-
trode, gas distributor and tip) require lubricating on
a scheduled basis. This will allow the o-rings to re-
main pliable and provide a proper seal. The o-rings
will dry out, becoming hard and cracked, if the o-
ring lubricant is not used on a regular basis. This can
lead to potential leaks internally and externally. Fail-
ure of o-rings that seal against outside “air” entering
the torch assembly can cause severe contamination.
These contaminants can destroy or shorten the parts
life of tips, electrodes, and internal torch parts.
It is recommended to apply a very light film of o-
ring lubricant, Catalog Number 8-4025, to the inter-
nal torch head assembly o-rings on a weekly basis.
NOTE
DO NOT use other lubricants or grease, they may
not be designed to operate within high tempera-
tures or may contain “unknown elements” that
may react with the atmosphere. This reaction can
leave contaminants inside the torch. Either of these
conditions can lead to inconsistent performance or
poor parts life.
5.03 Common Operating Faults
The following lists the more common cutting faults and
what is the possible cause:
1. Insufficient Penetration
a. Cutting speed too fast
b. Torch tilted too much
c. Metal too thick
d. Worn torch parts
e. Cutting current too low
f. 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. Non-Genuine Thermal Dynamics Parts
4. Short Torch Parts Life
a. Oil or moisture in air source
b. Exceeding system capability (material too thick)
c. Excessive pilot arc time
d. Starting or finishing off the workpiece
e. Plasma gas flow too low (incorrect pressure)
f. Improperly assembled torch
g. Output current too high
h. Torch tip contacting workpiece
i. Damaged or loose torch head components
j. Non-Genuine Thermal Dynamics Parts
5. Poor Pilot Starting
a. Non-Genuine Thermal Dynamics Parts
b. High coolant conductivity (refer to Power Supply
Manual)