Miller Big Blue 450 Duo (Dual Operator)


Multi-function Fuel Gauge
Displays fuel level and engine hours, and can be customized to set oil change interval reminders. In the case of high coolant temperature, low oil pressure, or low fuel level, the engine will shut down to prevent damage, or make restarting easier.
Heavy-Duty Low-Speed Mitsubishi S4L2 Industrial Diesel Engine
Used in industrial applications around the world, the S4L2 is designed to run 10,000 hours before major overhaul. Backed by worldwide support and service.
Adaptive Hot Start™ For Stick Arc Starts
Automatically increases the output of a weld should the start require it.  Prevents the electrode from sticking and creating an inclusion.
Superior Stick Arc Performance
Even on the difficult-to-run electrodes like E6010
Remote Amperage Control
Provided through 14-pin receptacle on front of the machine.  This permits use of standard and wireless remote amperage control devices.
Quiet Operation
At just 72.2 decibels at 23 feet (7 m), it's quieter than most single-operator models, improving jobsite communication and safety.
High Efficiency
Three-Phase, rotating-field generator requires less fuel and horsepower to operate.
Vandalism Lockout Kit
Lockable hinged steel panel protects front control panels and ignition switch.


Air Carbon Arc Cutting and Gouging (CAC-A)
Stick (SMAW)


TitleBig Blue 450 Duo CST (Mitsubishi)
Industries InterestsConstruction
Maintenance and Repair - Field Operations
Pipe Fabrication / Construction
Work / Service Trucks
Carbon Diameter3/16 in (4.8 mm)
Cold Weather Starting AidsGlow Plugs
Current TypeDC
Engine BrandMitsubishi
Engine ComplianceT4F
Engine Idle Speed1800 RPM
PortabilityLift Eye (Standard)
Trailer (Optional)
Engine Weld Speed1800 RPM
Fuel Tank Size11.5 Gallon
Net Height32 in
Fuel TypeDiesel
Net Length56 in
Horsepower24.7 hp
Max Open Circuit Voltage77 VDC
Net Weight1064 lbs
Weldable MetalsStainless Steel
Mild Steel
Net Width26.25 in
Rated OutputSeparate (Dual Outputs) 175 A at 27 V, 100% duty cycle
Single Phase Generator Continuous Power10000 W
WarrantyEngine Warranties 
Miller's True Blue Warranty
Sound Rating72.2 dB
Three Phase Generator Continuous Power12000 W
Amperage Range5 - 450