Tweco Pak 200 - Manual (Page 89)

Manual 0-5057 7-9 TORCH MAINTENANCE
TORCH MAINTENANCE PAK 200
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
qualifi ed electronic technician.
1. To test the Torch Head center insulator for insula-
tion breakdown use the following procedure:
a. Remove the Torch Head Assembly from the
Torch Leads if not already done.
b. Remove the consumables from the Torch Head
Assembly if not already done.
c. Connect a Hi-Pot Tester capable of producing
2500 VAC between the positive pilot lead and
the negative lead fi ttings.
d. Increase the output of the Hi-Pot Tester to a
maximum of 2500 VAC.
• If the voltage drops to 0 VAC or leakage current
is detected, then the Torch Head center insula-
tor is breaking down and the Torch Head must
be replaced.
• If the Torch Head center insulator passes the
test, then proceed to Step 2.
2. To test the Torch Leads for insulation breakdown
use the following procedure:
a. Connect the Hi-Pot Tester between the positive
pilot lead and the negative lead fi ttings. The fi t-
ting on the other end of the Torch Leads must
be separated (isolated) from each other.
b. Increase the output of the Hi-Pot Tester to a
maximum of 2500 VAC.
• If the voltage drops to 0 VAC or leakage cur-
rent is detected, then the insulation between
the Torch Leads is breaking down and the
Torch Leads must be replaced.
• If the Torch Leads passes the test, then
proceed to Step 3.
3. Visually check that the torch switch wires, pilot
lead connection, and negative lead connections
are properly connected and in good condition (no
shorts or arcing).
• If problems are evident, repair or replace as
required.
• If there are no visual problems, then proceed
to Step 4.
4. Check the pilot lead, negative lead and switch
control wires for opens from one end of the torch
leads to the other.
• If open, replace leads or open component of
the Torch Leads Assembly.
• If not open, then proceed to Step 5.
5. Check the pilot and switch control wires for shorts
to other components in the Torch Leads.
• If shorted, then replace Torch Leads.
• If not shorted, then proceed to Step 6.
6. Carefully reassemble the components and recheck
the completed assembly per paragraph ‘B’, Step 3
to confi rm that the components have been properly
assembled.
This completes the checks for the proper operation of the
Torch Head and Torch Leads.