Tweco ArcMaster 401S - Manual (Page 27)

ARCMASTER 401S POWER SOURCE
Manual 0-5345 3-7 INSTALLATION, OPERATION AND SETUP
1 VRD (Voltage Reduction Device) Indicator Lights
A VRD (voltage reduction device) is a hazard reducing device designed to reduce electric shock hazards present
on the output of welding power source when operating in SMAW (STICK) mode. Note that the presence of
VRD should not be used as a substitute for the use of appropriate safety practices as indicated in section one
of this manual.
Please Note: VRD is factory set to OFF on the 401S. The red LED will be on when unit is powered up. To enable,
turn VRD switch on Control PCB5 (refer to Figure 3-3) to the "ON" position. If VRD is active, green LED will
be on (standby below 12V). When arc is established, red LED will blink (above 12V).
VRD Switch
Control PCB5 Art # A-12454
Output Voltage
Adjustment
Potentiometer
Figure 3-3
2 Parameter Selection Button
This button is used to select between HOT START, WELDING CURRENT, and ARC FORCE while in SMAW (STICK)
mode and HOT START and WELDING CURRENT in TIG mode. Refer to 3.12 Special Function for more info.
3 Digital Meter Volt & Ammeter
Welding amperage, Voltage and parameter values are displayed in this window. Internal warnings such as over
temperature, low or high input voltage applied are signaled to the operator by error message on the screen.
When welding, it displays average welding current. After weld has been completed, it displays average welding
current for 10 seconds.
4 Encoder Control
It allows the operator to adjust the weld parameters within the entire range of the power source, also used to
set each parameter value. This control sets the selected weld parameter, rotating it clockwise increases the
parameter value and counterclockwise to decrease. A selected weld parameter can be adjusted at any time
even while welding. Refer to 3.12 Special Function for more info.
5 Process Selection Button
The process selection control is used to select the desired welding mode. Five modes available for 401S. These
modes are selected by pressing the selection button. For modes where there are two variations available press
and hold the button until it blinks to select the second function.