Tweco PCM-120 Machine Torch - Manual (Page 34)

CUSTOMER/OPERATOR SERVICE 5-4 Manual 0-2698
8. Install the tip and tighten with the multipurpose
wrench. Do not over tighten the tip.
CAUTION
Make sure both the tip and electrode correspond
with the plasma and secondary gases being used,
the current range, and the type of operation. Refer
to Section 4.04, Torch Parts Selection.
9. Hand tighten the shield cup until it is seated on the
torch head. If resistance is felt when installing the cup,
check the threads before proceeding.
5.05 Troubleshooting Guide
A. Troubleshooting
This Sub-Section covers troubleshooting that requires
disassembly and electronic measurements. It is helpful
for solving many of the common problems that can arise
with this torch assembly.
B. How to Use This Guide
The following information is a guide to help the Cus-
tomer/Operator determine the most likely causes for
various symptoms.
This guide is set up in the following manner:
X. Symptom (Bold Type)
Any Special Instructions (Text Type)
1. Cause (Italic Type)
a. Check/Remedy (Text Type)
Locate your symptom, check the causes (easiest listed first)
then remedies. Repair as needed being sure to verify that
unit is fully operational after any repairs.
A. Torch will not pilot when torch switch is activated
1. Power Supply RUN/SET switch in SET position
a. Place RUN/SET switch to RUN position.
2. Torch switch activated during 20 second pre-flow
a. Release torch switch and wait at least 20 sec-
onds before activating switch again.
3. Coolant return lead clogged or plugged.
a. Check coolant return into unit reservoir. In-
spect torch assembly and replace if necessary.
4. Faulty torch parts.
a. Inspect torch parts and replace if necessary. Re-
fer to Section 5.04, Inspection and Replacement
Consumable Torch Parts
5. Plasma gas pressure too high.
a. Set pressure to 65 psi (4.5 bar).
6. Faulty components in torch and leads assembly
a. Inspect torch assemblies and replace if neces-
sary. Refer to Section 5.08, Torch and Leads
Troubleshooting.
7. Faulty components in power supply system components
a. Return for repair or have qualified technician
repair per Service Manual.
B. No cutting output
1. Torch not properly connected to power supply
a. Check that torch leads are properly attached
to power supply.
2. Poor Work Cable Connection.
a. Inspect work cable connection and adjust if nec-
essary.
3. Faulty components in torch and leads assembly
a. Inspect torch assemblies and replace if neces-
sary. Refer to Section 5.08, Torch and Leads
Troubleshooting.
4. Faulty components in power supply system components
a. Return for repair or have qualified technician
repair per Service Manual.
C. Low cutting output with no control
1. Incorrect setting of AMPERAGE control on power sup-
ply.
a. Check and adjust to proper setting.
2. Faulty components in torch and leads assembly
a. Inspect torch assemblies and replace if neces-
sary. Refer to Section 5.08, Torch and Leads
Troubleshooting.
3. Faulty components in power supply system components
a. Return for repair or have qualified technician
repair per Service Manual.