Tweco PAK 200i - Manual (Page 79)

PAK 200i
Manual 0-5335 TORCH INFORMATION 7-11
In the Torch Leads the negative and positive leads are isolated from each other. If there is not adequate resistance
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 ohmmeter.
The actual assembly and consumables may vary for different torches but the basic procedure is the same for all
torches. Make the quick check on the Torch Head and Leads as follows:
WARNING
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.
�. Disconnect the torch leads from the power supply to isolate the torch from power supply circuits.
3. Using an ohmmeter (set to 10K or higher), check for continuity between the positive and negative torch fit-
tings.
• If there is continuity between the two torch fittings proceed to Step 4.
• If no continuity (infinite resistance) is found between the two torch fittings proceed to "C. Checking
Proper Insulation Resistance Procedure".
4. Remove the Torch Head from the leads (refer to Section "7.06 Servicing Hand Torch Components" on
page 7-7).
5. With the Torch Head disconnected from the leads, measure the resistance between negative fitting or cathode
body of the Torch Head and the positive fitting or anode body of the Torch Head.
No continuity (infinite resistance) should be measured between negative and positive sections of the Torch
Head.
• If there is continuity, Torch Head must be replaced.
• If no continuity (infinite resistance) is found proceed to Step 6.
6. Check the torch leads by measuring the resistance between the positive pilot lead connector and the negative
lead fitting.
• If there is continuity, torch leads must be replaced.
• If no continuity (infinite resistance) is found proceed to paragraph ‘C’ (see NOTE).
NOTE
It is possible that the Torch Head and Torch Leads will test properly with an ohmmeter. The Torch Head and Torch
Leads should be tested further for insulation breakdown if no other fault can be found.
C. Checking Proper Insulation Resistance Procedure
The Torch Head and Torch Leads should be tested further for insulation breakdown if no other fault has been found.
This procedure requires the use of a Hi-Pot Tester.
WARNING
This procedure should be performed only by a qualified electronic technician.