Tweco 300 DC Arcmaster - Manual (Page 61)

ARCMASTER 300 ACDC
February 22, 2006 11-3
C) Access the VRD control by gently prying back the front panel controls to reveal the VRD on/off potentiometer (see
Figure 11-3).
!
CAUTION
DO NOT pull back the front panel with excessive force as this will unplug control PCB. Plugging the control
PCB back into the front panel controls can only be achieved by removing the side covers.
VR1
Art # A-07081
Figure 11-3: VRD ON/OFF Step C and D
D) Turning the VRD ON/OFF (see Figure 11-3)
• To turn VRD ON: rotate the trim potentiometer on the display PCB fully clockwise. When VRD is turned ON check
that it operates as per VRD Specifications on page 11-1.
• To turn VRD OFF: rotate the trim potentiometer on the display PCB fully counter clockwise.
!
WARNING
The VRD ON/OFF trim potentiometer MUST ONLY be positioned fully clockwise OR fully counter clockwise
as the VRD function will be unknown for every other position.