Tweco 300 Maximizer - Manual (Page 36)

SERVICE 5-6 Manual 0-2554
Plasma (+) Lead
Coolant Return Lead
(LH Threads)
Secondary
Lead
Coolant
Supply (-) Lead
A-00664
Figure 5-6 Torch Head Removal
B. Reassembling Machine Torch Assembly
1. Connect the plasma (+), secondary, coolant sup-
ply (-), and coolant return connectors.
2. Slide the torch adapter down over the leads and
screw the adaptor securely onto the back of the
torch head assembly.
3. Slide the positioning tube down over the leads
and thread it into the torch adaptor on the torch
head assembly.
4 . Install the front end torch parts.
5.07 Torch & Leads Troubleshooting
A. General Information
Failures in the Torch and Leads can be isolated to the Torch
Head or Torch Lead components. To properly isolate the
failed part requires the use of an ohmmeter and a Hi-Pot
Tester.
WARNING
The use of a Hi-Pot Tester should be performed only
by a qualified electronic technician.
In the Torch Head the center insulator separates the nega-
tive and positive charged sections of the torch. If the cen-
ter insulator does not provide adequate resistance, cur-
rent which is intended for the pilot arc may be dissipated
into the torch head, resulting in torch failure.
In the Torch Leads the negative and positive leads are
isolated from each other. If there is not adequate resis-
tance between the leads then torch failure may occur.
B. Quick Check Procedure
This quick check will identify major isolation failures in
the Torch Head or Torch Lead components using an ohm-
meter.
The actual assembly and consumables may vary for dif-
ferent torches but the basic procedure is the same for all
torches. Make the quick check on the Torch Head and
Leads per the following procedure:
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 consumables from the torch.
2. Disconnect the torch leads from the power sup-
ply to isolate the torch from power supply circuits.