Thermal Arc 185 AC, Service Manual

Page: 68 / 122

10-18
May 22, 2006
ARCMASTER 185 ACDC 200 ACDC
Figure 10-18: Removal and installation from the HF
UNIT1 (To disable the operation of the HF unit.)
4) Press the Welding mode selection button to select
HF TIG welding mode.
5) While depressing the Torch switch, verify the OCV
using a DC voltmeter. (The capability of the
voltmeter should be more than 100VDC.) The
check point with a tester is the voltage between
output te and -. In TIG mode, the OCV
ceases 3 seconds after you depress the torch
switch.
6) The normal no-load voltage is approximately 58-
62V.
7) Return the variable resistor (VR1) to the
original position.
• Fully clockwise: VRD ON
• Fully counter-clockwise: VRD OFF
8) Return connection with HF UNIT1 to the original
position.