Tweco PCM - 102 Machine Torch - Manual (Page 33)

Manual 0-2818 5-1 SERVICE
SECTION 5:
SERVICE
5.01 Introduction
This section describes basic maintenance procedures per-
formable by operating personnel. No other adjustments
or repairs are to be attempted by other than properly
trained personnel.
WARNINGS
Disconnect primary power at the source before dis-
assembling the torch or torch leads.
Frequently review the Important Safety Precau-
tions at the front of this Manual. Be sure the op-
erator is equipped with proper gloves, clothing, eye
and ear protection. Make sure no part of the
operator’s body comes into contact with the work-
piece while the torch is activated.
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.
5.02 General Torch Maintenance
A. Cleaning Torch
Even if precautions are taken to use only clean air
with a torch, eventually the inside of the torch be-
comes coated with residue. This buildup can affect
the pilot arc initiation and the overall cut quality of
the torch.
WARNINGS
Disconnect primary power to the system before
disassembling the torch or torch leads.
DO NOT touch any internal torch parts while the
AC indicator light of the Power Supply is ON.
The inside of the torch should be cleaned with elec-
trical contact cleaner using a cotton swab or soft wet
rag. In severe cases, the torch can be removed from
the leads and cleaned more thoroughly by pouring
electrical contact cleaner into the torch and blowing
it through with compressed air.
Refer to Section 5.07, Servicing Hand Torch (PCH)
Components, or Section 5.08, Servicing Machine
Torch Components (PCM) for disassembling the
Torch and Leads Assembly.
CAUTION
Dry the torch thoroughly before reinstalling.
B. Checking Center Insulator
The center insulator separates the negative and posi-
tive sections of the torch. If the center insulator does
not provide adequate resistance, current which is in-
tended for the pilot arc may be dissipated into the
torch head, resulting in torch failure.
WARNINGS
Disconnect primary power to the system before
disassembling the torch or torch leads.
DO NOT touch any internal torch parts while the
AC indicator light of the Power Supply is ON.
1. Remove the shield cup, tip, gas distributor, and
electrode from the torch. Disconnect the torch
leads from the power supply to isolate the torch
from power supply circuits.
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 5.06, Torch and Leads Troubleshooting.
C. O-Ring Lubrication
The external o-ring on the Torch Head Assembly
(shield cup) requires lubrication on a scheduled ba-
sis. This will allow the o-ring to remain pliable and
provide a proper seal. The o-ring will dry out, be-
coming hard and cracked, if the o-ring lubricant is
not used on a regular basis. This can lead to poten-
tial leaks of the secondary gas around the end of the
shield cup.
It is recommended to apply a very light film of o-
ring lubricant (Catalog # 8-4025) to the o-ring on a
weekly basis.