Miller Big Blue 400 X Pro

Superior Arc Performance

  • Four pre-set DIG settings (Stick).
  • Hot Start™ (Stick).
  • Lift-Arc™ TIG with Auto-Stop™ and Crater-out.
  • MIG/FCAW arc performance.

Auto Remote Sense™

Detects if a remote control is plugged into the 14-pin receptacle and eliminates confusion of a remote/panel switch.

Caterpillar Heavy Duty Low-Speed Industrial Engine

Designed to operate for 10,000 hours before the first basic overhaul.

Quiet Operation

Improves work site communication.

The Vault: Ultimate Control Board Reliability

Ultimate control board reliability. Solid-state control technology, housed in a sealed vault. The vault’s sealed connections are made through watertight plugs that make these components impenetrable to dust and moisture.

Simple-to-Set Controls

No elaborate procedure, just select process and weld!

Meter Maintenance Displays

  • Fuel gauge.
  • Hour meter function.
  • Oil change interval.
  • High coolant temperature and low oil pressure shut downs.
  • Low fuel shutdown - engine shuts down before system runs out of fuel, making restarts easy.

Auxiliary Power*

  • 2 X 15 Amp Sockets.
  • 1 X 32 Amp Sockets.
  • RCD.

*Generator auxiliary power is 60Hz, and intended for operating equipment associated with welding, such as angle grinders, drills  and floodlights. Some Australian 50Hz equipment incorporating induction motors, such as pumps, fans, air compressors, refrigeration or air-conditioners, may not operate correctly and could be damaged. Refer to appliance supplier or manufacturer to confirm suitability.

Technical Data

Welding Mode:  CC/DC, CV/DC

Amp/Volt Range: 20 - 400 A, 14- 400 V

Rated Output: 300 A at 32V, 100% Duty cycle, 350 A at 27V 100% Duty cycle, 400 A at 24 V 100 Duty Cycle

Generator Power: Peak 12 000 Watts, Continuous: 10 000 Watts, 42 A, 240 VAC, 60 Hz

Dimensions (mm): H 813  W: 667  D: 1422

Weight (without Fuel): 458 kg

Applications and Processes


Structural Steelwork



Mechanical Contractors







Flux Cored


Air Plasma Cutting and Gouging with Optional Spectrum Models

Air Carbon Arc