SECTION 5
PCM-875A Plasmarc Cutting System
Maintenance
5-7
5.3.2 Dirt or Contamination
Dirt or other contamination in the torch and loose
consumable parts can cause premature failure of
the PT-20AM Torch through internal arcing. To
avoid this, users are instructed to do the following:
1. Ensure that clean, dry, or oil-free air is being
used.
2. Avoid excessive use of the silicone o-ring
grease used to lubricate the torch o-ring. A thin
film is sufficient.
3. Wipe the torch body insulator clean with a
cloth before installing each fresh set of
consumables. The ability of the insulator to resist
arc tracking over its surface is reduced when dirt
or other contamination is allowed to collect there.
5.3.3 Loose Consumables
Tests have shown that with proper use of the torch
within rated operating conditions (especially arc
current and gas flow rate), the torch consumable
parts do not become loose if they are firmly
installed in the first place.
1. Tighten heat shield fully at each consumable
change or inspection. “Fully” means at least 5
mm of rotation after electrode seat contacts
electrode holder.
NOTE: trying to rotate the portion of the nozzle
extending outside heat shield can check
consumable tightness.
2. Check consumable tightness at beginning of
each work shift, even if everything was working
normally at the end of the previous shift.
3. Ensure that the torch electrode seat and
electrode holder are clean and free of dust or dirt
Debris may prevent mating surfaces from having
solid contact.
