MasterWeld 300 MMA Digital Inverter Welder

Stock Code: MW.1504

7-10 Day Delivery
£2,742.00 inc VAT £2,285.00 ex VAT Per Each

Product Overview

The MasterWeld 300 is a European-manufactured, heavy-duty 300 amp three-phase inverter welder for professional MMA stick welding, including cellulosic electrodes, and Lift TIG DC applications. Designed for demanding fabrication, construction, shipyard and maintenance work, it combines robust construction with precise digital control.

Adjustable Hot Start and Arc Force help deliver reliable arc ignition and stable welding performance, while built-in VRD reduces open-circuit voltage when the machine is idle. Delivering 200 amps at 100% MMA duty cycle at 40°C, the MasterWeld 300 provides sustained industrial welding capacity, backed by a three-year warranty and full UK support.

Product Features

The MasterWeld 300 combines industrial welding power with adjustable arc control for professional fabrication, maintenance and repair. European manufactured and built for demanding working environments, it offers MMA stick welding, dedicated cellulosic electrode capability and Lift TIG DC in one robust machine.

Professional MMA and Cellulosic Welding

With a welding current range of 10–300 amps, the MasterWeld 300 handles a wide range of MMA electrodes up to 6 mm diameter, depending on electrode type and application. The dedicated MMA CELL function provides the responsive current control needed to maintain a stable arc with cellulosic electrodes, making it particularly useful for pipework and demanding site applications.

  • Adjustable Hot Start: boosts starting current to help establish the arc reliably.
  • Adjustable Arc Force: helps maintain arc stability and reduce electrode sticking as the arc length shortens.
  • Anti-Sticking: helps release the electrode if it accidentally sticks to the workpiece.
  • Cellulosic electrode mode: supports demanding pipe welding, construction and maintenance applications.

Digital Welding Control

A clear digital display makes welding settings easy to read and repeat, while microprocessor control manages welding parameters in real time. Adjustable controls allow the operator to tailor the arc response to the electrode, joint and working technique.

Built for Demanding Industrial Work

Robust construction and a built-in wind tunnel help protect the electronics from dust and salt contamination. The MasterWeld 300 is designed for challenging environments, including fabrication workshops, shipyards, construction projects and offshore maintenance.

Delivering 200 amps at 100% MMA duty cycle at 40°C, it provides sustained welding capacity for extended fabrication and repair work.

  • Industrial fabrication and general engineering
  • Structural steelwork and construction
  • Plant, machinery and equipment repairs
  • Pipework and maintenance welding
  • Shipbuilding and marine repairs
  • Offshore and oil and gas maintenance

Voltage Reduction Device — VRD

The built-in Voltage Reduction Device reduces the open-circuit voltage when the machine is not welding. The specified reduced voltage is 9 V, compared with the normal open-circuit voltage of 76 V. This supports applications where reduced idle voltage is required by site procedures.

Lift TIG DC and Pulsed TIG Capability

Lift TIG DC extends the machine's versatility for suitable materials such as mild steel and stainless steel. A 5–300 amp TIG current range provides flexibility for a variety of fabrication and maintenance tasks.

Adjustable TIG pulse frequency and background current give the operator additional control over heat input and the weld pool, helping manage distortion. Lift-start ignition helps reduce the risk of tungsten contamination compared with conventional scratch starting.

TIG welding requires a suitable valve-controlled torch, shielding gas and associated equipment. The torch should be selected to suit the welding current and duty cycle required.

Technical Specifications

Welding processes MMA / stick, MMA cellulosic and Lift TIG DC
Input supply 400 V three-phase AC, ±15%, 50–60 Hz
Specified supply fuse T20 A time-delay fuse
Maximum input power 13.3 kVA / 10.7 kW
MMA welding current range 10–300 A
TIG welding current range 5–300 A
Open-circuit voltage 76 V
Reduced voltage with VRD 9 V
Electrode capacity Up to 6 mm, depending on electrode type and application
Protection rating IP23S
Dimensions 460 × 230 × 325 mm
Weight 20.8 kg
Manufacture European manufactured
Warranty Three years with full UK support

Welding Output and Duty Cycle

Process Temperature Output and duty cycle
MMA 40°C 300 A at 40%; 230 A at 60%; 200 A at 100%
TIG DC 40°C 300 A at 50%; 250 A at 60%; 210 A at 100%
MMA 25°C 300 A at 60%; 250 A at 100%
TIG DC 25°C 300 A at 80%; 270 A at 100%

Duty cycle is measured over a 10-minute period at the stated ambient temperature. For example, 40% duty cycle allows four minutes of welding followed by six minutes of cooling at the specified output.

Accessory Options

  • Electrode holder with 4 m, 35 mm² welding lead
  • Work return clamp with 4 m, 35 mm² cable
  • 4 m Type 26 valve-controlled TIG torch for work within its rated capacity
  • Remote current control
  • Transport trolley

Contact us to confirm compatible accessories and the equipment included in your chosen package.

Three-Year Warranty and Full UK Support

The MasterWeld 300 is European manufactured and backed by a three-year warranty with full UK support. Our team can help with machine selection, suitable accessories and after-sales assistance.

Contact MasterWeld for a quotation or help specifying the right welding package for your application.

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Company Registration: 07988136 Registered Office: Olympic House, Collett, Southmead Park, Didcot, Oxfordshire, United Kingdom, OX11 7WB

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