4.ARC CONTROL- The ARC CONTROL dial is active in the CV-WIRE, CC-STICK and DOWNHILL PIPE modes, and has different functions in these modes. This control is not active in the TIG and ARC GOUGING mode.
CC-STICK mode: In this mode, the ARC CONTROL dial sets the short circuit current (arc-force) during stick welding to adjust for a soft or crisp arc. Increasing the dial from –10 (soft) to +10 (crisp) increases the short circuit current and prevents sticking of the electrode to the plate while welding. This can also increase spatter. It is recommended that the ARC CONTROL be set to the minimum number without electrode sticking. Start with a setting at 0.
DOWNHILL PIPE mode: In this mode, the ARC CONTROL dial sets the short circuit current (arc-force) during stick welding to adjust for a soft or a more forceful digging arc (crisp). Increasing the number from –10 (soft) to +10 (crisp) increases the short circuit current which results in a more forceful digging arc. Typically a forceful digging arc is pre- ferred for root and hot passes. A softer arc is preferred for fill and cap passes where weld puddle control and deposition ("stacking" of iron) are key to fast travel speeds. It is recom- mended that the ARC CONTROL be set initially at 0.
CV-WIRE mode: In this mode, turning the ARC CONTROL clock wise from –10 (soft) to +10 (crisp) changes the arc from soft and washed-in to crisp and narrow. It acts as an inductance/pinch control. The proper setting depends on the procedure and operator preference. Start with a setting of 0.
5. WELD OUTPUT TERMINALS WITH FLANGE NUT-
work cables.
6.GROUND STUD- 
Provides a connection point for connecting the machine case to earth ground.
7.14-PIN CONNECTOR- For attaching wire feeder con- trol cables. Includes contactor closure circuit, auto-sensing remote control circuit, and 42V power. The remote control circuit operates the same as the 6 Pin Amphenol.
8.3-PIN CONNECTOR- For attaching optional remote control equipment. Includes auto-sensing remote control circuit.
9.WELD TERMINALS CONTROL SWITCH- In the WELD TERMINALS ON position, the output is electrically hot all the time. In the REMOTELY CONTROLLED posi- tion, the output is controlled by a wire feeder or amptrol device, and is electrically off until a remote switch is depressed.
10. WIRE FEEDER VOLTMETER SWITCH:
Matches the polarity of the wire feeder voltmeter to the polarity of the electrode.
11. VRD (Voltage Reduction Device) INDICA- TOR LIGHTS- On the front panel of the DX450
are two indicator lights. A red light when lit indicates OCV(Open Circuit Voltage) is equal to or greater than 30V and a green light when lit indicates OCV(Open Circuit Voltage) is less than 30V.
The VRD “On/Off” switch inside the control panel must be “On” for the VRD function to be active and the lights to be enabled. When the machine is first started with VRD enabled, both lights will illuminate for 5 seconds.
These lights monitor the OCV(Open Circuit Voltage) and weld voltage at all times. In the CC-Stick mode when not welding the green light will illuminate indi- cating that the VRD has reduced the OCV to less than 30V. During welding the red light will illuminate whenever the arc voltage is equal to or greater than 30V. This means that the red and green light may alternate depending on the weld voltage. This is nor- mal operation.
If the red light remains illuminated when not welding in the CC-stick mode, the VRD is not functioning properly. Please refer to your local field service shop for service.
If the VRD is turned “On” and the lights don’t come “On”, refer to the trouble shooting section.
TABLE B.1
VRD INDICATOR LIGHTS
MODE | | VRD "ON" | VRD "OFF" |
CC-STICK | OCV | Green (OCV Reduced) | |
| While | Red or Green | |
| Welding | (Depends on Weld Voltage) * | |
CV-WIRE | OCV | Red (OCV Not Reduced) | |
| | Weld Terminals On | |
| | Red (OCV Not Reduced) | |
| | Weld Terminals Remotely Controlled | |
| | Gun Trigger Closed | |
| | Green (No OCV) | | | |
| | Weld Terminals Remotely Controlled | |
| | Gun Trigger Open | No Lights |
| While | Red or Green | | |
| Welding | (Depends on Weld Voltage) * | |
PIPE | OCV | Green (No Output) | | | | |
| While | Not Applicable (No Output) | | |
| Welding | | | | | | |
ARC GOUGING | OCV | Green (No Output) | |
| While | Not Applicable (No Output) | |
| Welding | | | | | | |
TIG | OCV | Green (Process is Low Voltage) | |
| While | Green (Process is Low Voltage) | | | |
| Welding | | | | | | |
| | | | | | | |
*It is normal for the lights to alternate between colors while welding.
