Multimatic 255 MIG Multi Process Power Source
Easy to Use. Versatility. Portability
Built for professionals in the MRO and manufacturing/fabrication segments who want a smaller, versatile welder with intuitive setup to increase efficiencies and productivity. This 250-amp inverter multiprocess welder is easy to use, will deliver versatility for faster uptime and performance, while allowing for portability.
Features and Benefits
Easy-to-understand interface with 7-inch color LCD display ensures proper machine setup and parameter selection, reducing setup time and increasing weld time.
- Quick-access process and weld mode backlit buttons across the top illuminate when active.
- Soft-key buttons below the display change function depending on which screen is displayed. Makes setup or change quick, easy and intuitive.
- Large text for easier readability.
- Intuitive connection setup images.
- Full troubleshooting descriptions versus help errors and look up codes.
Auto-Set™ offers predefined weld settings to increase ease of use and ensure that the job is done right for operators of all skill levels.
- Available for MIG, pulsed MIG, stick and DC TIG processes with the ability to fine-tune your settings.
- Set weld parameters by selecting:
- MIG (shown) — wire and gas type, wire diameter and material thickness Stick — electrode type, electrode diameter and material thickness DC Lift-Arc™ TIG — remote on/off, tungsten diameter and material thickness
MDX™-250 MIG gun with
MDX™ MIG gun consumables features a dual-locked, front-loading liner that optimizes wire feedability.
- Coarse threads on MDX contact tips speed up tip replacement.
- Front load liner locks at front and back of gun to align with contact tip and power pin for a flawless wire feed path.
- Durable, ergonomic handle with overmolding improves grip and comfort.
- Ball-and-socket handle with rear swivel for increased gun maneuverability while reducing welder fatigue.
Program mode allows easy save and recall of favorite weld settings.
- Save up to four programs for each process.
- Deliver more productivity by eliminating need to manually set parameters.
- Deliver consistent quality by welders of all skill levels with prequalified settings.
- Minimize supervisor intervention.
Versatility
Multiprocess capabilities include MIG, flux cored, DC stick (6010) and DC Lift-Arc™ TIG welding. The Multimatic 255 also has pulsing capability that allows it to do pulsed MIG and TIG welding.
- Compatible with push-pull MIG guns. Increases productivity by allowing the use of 12-inch wire spools versus a spool gun’s 4-inch spools. Reduces downtime from changing wire spools.
- Auto-Gun Detect™ automatically adjusts voltage, wire speed and timers for faster switching between MIG, push-pull and spool guns.
For portability and reliability Auto-Line™ allows for any single-phase input voltage hookup (208–575 V) with no manual linking, providing convenience in any job setting. Ideal solution for dirty or unreliable power.
Generator compatible
The Multimatic 255 will be able to operate and provide full output when powered by generators with 12,000-watt (12 kW) output or higher. Limited output will occur when used with smaller generators.
Pulsed MIG
welding delivers higher quality welds for ALL welders.
- Lower heat input for less distortion on thin materials and better puddle control on out-of-position welds.
- Less spatter minimizes post weld grinding and rework, allowing more welding time.
- Perform welding applications that couldn’t be done in the past.
- Ideal for MIG welding aluminum and stainless steel.
Ratings A, B, C, and D are relative values. An “A” rating indicates a best fit between your performance needs and process. A “blank” rating indicates that the process is not recommended for that application.
Portability
Weighing only 84 pounds, the weight of the Multimatic 255 has been reduced by more than 50 percent compared to the Millermatic® 252.
Optional EZ-Latch™ running gear
EZ-Latch running gears are available in single cylinder and dual cylinder models (included with package or can be ordered separately). Operators no longer need to lift machine AND running gear into the truck. Latches secure machine to running gear. Simply loosen the latch retaining knob and rotate latches to disengage machine from running gear for easy portability. Cylinder racks feature bottle forward technology for increased stability when moving along an incline and running gears have built-in storage for accessories. Dual cylinder model includes an elevated gun and cable rack to keep cables off the floor and tangle free.
Specifications
| Welding Mode / Process | Welding Amperage Range | Rated Output | Amps Input at Rated Output (50/60 Hz) 208V / 240V / 460V / 575V / KVA / KW | Wire Feed Speed | Max. Open-Circuit Voltage | Dimensions | Net Weight |
|---|---|---|---|---|---|---|---|
| CV: MIG / flux-cored | 20–350 A | 230 A at 25.5 V, 60% duty cycle | 34.7 / 29.7 / 17.1 / 14.3 / 8.2 / 8.2 | 50–800 ipm (1.3–20 m/min.) | 81 VDC | Machine only: H: 19.25 in. (489 mm) W: 13.75 in. (349 mm) D: 24.25 in. (616 mm) With running gear: H: 32 in. (813 mm) W: 13.75 in. (349 mm) D: 45 in. (1,143 mm) | Machine only: 84 lb. (38 kg) With running gear: 148 lb. (67 kg) |
| CC: Stick* | 30–275 A | 200 A at 28 V, 60% duty cycle | 33.5 / 29 / 16.4 / 13.6 / 7.8 / 7.8 | — | |||
| CC: DC TIG | 5–275 A | 275 A at 21 V, 60% duty cycle | 34.1 / 29.9 / 17 / 14.1 / 8.1 / 8.1 | — |
Performance Data
Control Panel
- TIG Process Button
- Stick Process Button
- MIG Process Button
- USB Port
- Color LCD Display
- Left Adjustment Knob(adjusts voltage, arc length, pulse frequency or parameter values depending on mode)
- Auto-Set™ Button
- Pulse Button
- Power On/Off Switch
- Right Adjustment Knob (adjusts wire feed speed, amperage or parameter values depending on mode)
- Soft Keys (multiple functions depending on screen displayed)
Multimatic® 255 Packages
Machine only comes complete with:
- Power source with 10 ft. (3 m) industrial power cord
- 15 ft. (4.6 m) 250-amp MDX™-250 MIG gun with MDX™ heavy duty consumables for .035/.045 in. (0.9/1.2 mm) wire
- 10 ft. (3 m) cable with electrode holder and 50 mm Dinse-style connector
- 10 ft. (3 m) work cable with clamp and 50 mm Dinse-style connector
- Flow gauge regulator and gas hose for argon or AR/CO2 mix
- .035/.045 in. (0.9/1.2 mm) reversible drive rolls
- Extra contact tips
- Material thickness gauge
Machine with running gear package comes complete with
- Power source with 10 ft. (3 m) industrial power cord
- 15 ft. (4.6 m) 250-amp MDX™-250 MIG gun with MDX™ heavy duty consumables for .035/.045 in. (0.9/1.2 mm) wire
- 10 ft. (3 m) cable with electrode holder and 50 mm Dinse-style connector
- 10 ft. (3 m) work cable with clamp and 50 mm Dinse-style connector
- Flow gauge regulator and gas hose for argon or AR/CO2 mix
- 035/.045 in. (0.9/1.2 mm) reversible drive rolls
- Extra contact tips
- Material thickness gauge
- EZ-Latch™ single cylinder running gear
- Chain to secure gas cylinder
Machine with dual cylinder/TIG kit package comes complete with
- Power source with 10 ft. (3 m) industrial power cord
- 15 ft. (4.6 m) 250-amp MDX™-250 MIG gun with MDX™ heavy duty consumables for .035/.045 in. (0.9/1.2 mm) wire
- 10 ft. (3 m) cable with electrode holder and 50 mm Dinse-style connector
- 10 ft. (3 m) work cable with clamp and 50 mm Dinse-style connector
- Flow gauge regulator and gas hose for argon or AR/CO2 mix
- .035/.045 in. (0.9/1.2 mm) reversible drive rolls
- Extra contact tips
- Material thickness gauge
- EZ-Latch™ dual cylinder running gear with elevated gun and cable rack
- Two chains to secure gas cylinders
- Multimatic 235/255 TIG kit
Genuine Miller® Accessories
EZ-Latch™ Single Cylinder Running Gear 301449 Running gear with a single cylinder rack and storage compartment. Latches secure machine to cart. Simply rotate latches to disengage machine from cart for easy portability. 
EZ-Latch™ Dual Cylinder Running Gear 951769
Similar to above, but with dual cylinder rack which allows operator to easily store two gas cylinders. Includes elevated gun and cable rack (shown at right) to keep cables off the floor and tangle free.
EZ-Latch™ Dual Cylinder Rack with Elevated Gun and Cable Rack 301481 Converts an EZ-Latch single cylinder running gear into a dual cylinder rack to easily store two gas cylinders. Gun and cable rack keeps cables off the floor and tangle free. (Included with EZ-Latch dual cylinder running gear.)
Protective Cover 301521
Features side pocket.
Argon/Mixed Gas Regulator and Gas Hose 195050
MIG Guns
- MDX™-250 MIG Gun with
- MDX™ Heavy Duty Consumables 1770043 15 ft. (4.6 m)
- Industrial 250-amp MIG gun with consumables for .035/.045 in. (0.9/1.2 mm) wire.
- MDX™-250 MIG Gun with
- MDX™ Standard Duty Consumables 1770035 10 ft. (3 m)
- 1770037 15 ft. (4.6 m)
- Industrial 250-amp MIG gun with consumables for .030/.035 in. (0.8/0.9 mm) wire.
Spoolmatic® Spool Guns
- 195156
- 15 ft. (4.6 m)
- 130831
- 30 ft. (9.1 m)
Ideal for aluminum welding jobs. Air-cooled, one-pound spool gun with 15-foot (4.6 m) or 30-foot (9.1 m) cable assembly. Rated at 200 amps at 100 percent duty cycle. For detailed information, see Spoolmatic literature M/1.73.
Spoolmate™ 200 Spool Gun 300497 Reliable and economical spool gun perfect for hobbyists and light fabricators who weld aluminum. Handles .030–.035 inch (0.8–0.9 mm) aluminum wires and .023–.035 inch (0.6–0.9 mm) steel/stainless steel wires. Rated at 160 amps, 60 percent duty cycle with 20-foot cable assembly. For detailed information, see Spoolmate literature M/1.47. 
Optional Spoolmate™ 200 Head Tubes
- 300591 45-degree head tube
- 300592 9-inch extension head tube
- 243385 5-inch head tube
XR-Aluma-Pro™ Push-Pull Guns
- 301568 15 ft. (4.6 m)
- 301569 25 ft. (7.6 m)
- Air-cooled gooseneck-style gun for
- 030–.047 inch (0.8–1.2 mm) aluminum. Rated at 300 amps at 100 percent duty cycle.
XR-Aluma-Pro™ Lite Push-Pull Gun
- 300948 25 ft. (7.6 m)
- Air-cooled gooseneck-style gun for .030–.047 inch (0.8–1.2 mm) aluminum.
- Rated at 175 amps at 60 percent duty cycle.
- XR™-Pistol-Pro Push-Pull Guns
- 300782
- 15 ft. (4.6 m)
- 300783
- 25 ft. (7.6 m)
Air-cooled pistol-grip gun for .030–.047 inch (0.8–1.2 mm) aluminum. Rated at 200 amps at 100 percent duty cycle.
U-Grooved Aluminum Drive Roll and Accessory Kits for XR-Aluma-Pro Push-Pull Guns
- 195311 .035 in. (0.9 mm)
- 195313 .047 in. (1.2 mm)
- Kits include Multimatic® U-grooved drive rolls, nylon wire guides and contact tips.
TIG Accessories
Multimatic® 235/255 TIG Kit 301518
Kits comes complete with everything needed to TIG weld with the Multimatic 255. Includes 25-foot (7.6 m) Weldcraft™ A-150 TIG torch, RFCS-14 HD foot control, 10-pin to 14-pin adapter cord, flow gauge regulator with 5-foot (1.5 m) gas hose, and AK3C torch accessory kit.
Wireless Remote Foot Control 301580
For remote current and contactor control. Receiver plugs directly into the 14-pin receptacle of Miller machine. 90-foot (27.4 m) operating range.
Note: Multimatic 255 is not compatible with wireless hand control.
RFCS-14 HD
Foot Control 301589
Heavy-duty foot pedal current and contactor control provides increased stability and durability from larger base and heavier cord. Includes 20-foot (6 m) cord with plug. 
RCC-14 Remote Contactor and Current Control 151086
East/west rotary-motion fingertip control attaches to TIG torch using two hook-and-loop fasteners. Includes 26.5-foot (8 m) cord with 14-pin plug.
RCCS-14 Remote Contactor and Current Control 043688
North/south rotary-motion fingertip control attaches to TIG torch using two hook-and-loop fasteners. Includes 26.5-foot (8 m) cord with 14-pin plug.
10-Pin to 14-Pin Adapter Cord 301545 Allows standard 14-pin TIG remote controls to be used with the Multimatic 255.
Consumables
| T-A023CHM | .023 in. (0.6 mm) |
| T-A030CHM | .030 in. (0.8 mm) |
| T-A035CHM | .035 in. (0.9 mm) |
| T-A039CHM | .039 in. (1.0 mm) |
| T-A045CHM | .045 in. (1.2 mm) |
Nozzles
| N-M5800CM | Copper, 5/8 in. ID, flush, standard |
| N-M5818CM | Copper, 5/8 in. ID, 1/8 in. recess |
| N-A5814CM | Copper, 5/8 in. ID, 1/8 in. stickout |
Diffuser: D-MA250MMonocoil Replacement Liners (10 ft.)
| LM1A-10 | .023/.025 in. (0.6 mm) |
| LMD2A-10 | .030/.035 in. (0.8/0.9 mm) |
| LMD3A-10 | .035/.045 in. (0.9/1.2 mm) |
Monocoil Replacement Liners (15 ft.)
| LM1A-15 | .023/.025 in. (0.6 mm) |
| LMD2A-15 | .030/.035 in. (0.8/0.9 mm) |
| LMD3A-15 | .035/.045 in. (0.9/1.2 mm) |
| T-M023 | .023 in. (0.6 mm) |
| T-M030 | .030 in. (0.8 mm) |
| T-M035 | .035 in. (0.9 mm) |
| T-M045 | .045 in. (1.2 mm) |
| T-M047 | 3/64 in. (1.2 mm) |
Nozzles
| N-M1200C | Copper, 1/2 in. ID, flush, standard |
| N-M1218C | Copper, 1/2 in. ID, 1/8 in. recess |
| N-M5800C | Copper, 5/8 in. ID, flush |
| N-M5818C | Copper, 5/8 in. ID, 1/8 in. recess |
| N-M58XTC | Copper, 5/8 in. ID, 1/8 in. stickout |
Diffuser: D-M250
Note: Miller® FasTip™, M-Series and Bernard® Centerfire™ diffusers and consumables are NOT compatible with MDX Series guns.
| 206186 | Heavy-duty, .030 in. (0.8 mm) |
| 206187 | Heavy-duty, .035 in. (0.9 mm) |
| 206188 | Heavy-duty, .040 in. (1.0 mm) |
| 206189 | Heavy-duty, 3/64 in. (1.2 mm) |
| 206191 | Heavy-duty, 1/16 in. (1.6 mm) |
| 209026 | Tapered, .030 in. (0.8 mm) |
| 209027 | Tapered, .035 in. (0.9 mm) |
| 209029 | Tapered, 3/64 in. (1.2 mm) |
| 209030 | Tapered, 1/16 in. (1.6 mm) |
Screw-On Nozzles
| 199610 | Brass, 1/2 in. orifice, tapered |
| 199613 | Brass, 5/8 in. orifice, tapered |
| 199614 | Brass, 5/8 in. orifice, tapered HD |
| 199611 | Brass, 3/4 in. orifice, straight |
| 199612 | Brass, 3/4 in. orifice, straight HD |
| 209035 | Copper, 3/8 in. orifice, tapered |
| 199615 | Copper, 1/2 in. orifice, tapered |
| 209036 | Copper, 1/2 in. orifice, tapered HD |
| 198855 | Copper, 5/8 in. orifice, tapered |
| 199618 | Copper, 5/8 in. orifice, tapered HD |
| 207313 | Copper, 5/8 in. orifice, tapered 15/16 OD |
| 199616 | Copper, 3/4 in. orifice, straight |
| 199617 | Copper, 3/4 in. orifice, straight HD |
Bernard® Centerfire™ “T” Series Contact Tips
| T-035AL | .035 in. (0.9 mm) |
| T-047AL | .047 in. (1.2 mm) |
| T-062AL | 1/16 in. (1.6 mm) |
| NS-5818B | Brass, 5/8 in. ID, 1/8 in. tip recess |
| NS-1218B | Brass, 1/2 in. ID, 1/8 in. tip recess |
| NS-1200B | Brass, 1/2 in. ID, flush tip |
| NST-3818B | Brass, 3/8 in. ID, 1/8 in. tip recess |
| NS-1218C | Copper, 1/2 in. ID, 1/8 in. tip recess |
| 199387 | .030 in. (0.8 mm) |
| 199388 | .035 in. (0.9 mm) |
Nozzle: 050622
For Optional Head TubesNote: The same consumables are used on 45-degree, 5-inch, and 9-inch extension head tubes.
Contact Tips (5 per package)
| 199730 | .024 in. (0.6 mm) (requires V-knurled drive roll 136135) |
| 186419 | .030 in. (0.8 mm) |
| 186406 | .035 in. (0.9 mm) |
Nozzle: 186405
| 204579 | .030 and .035 in. (0.8 and 0.9 mm) combination (reversible) |
| 087131 | .024 in. (0.6 mm) |
| 079594 | .030 in. (0.8 mm) |
| 079595 | .035 in. (0.9 mm) |
| 079596 | .045 in. (1.2 mm) |
| 079606 | .035 in. (0.9 mm) |
| 079607 | .045 in. (1.2 mm) |
| 079608 | .052 in. (1.3 mm) |
| 044749 | .035 in. (0.9 mm) |
| 079599 | .047 in. (1.2 mm) |
Ordering Information
| Equipment and Options | Stock No. | Description |
|---|---|---|
| Multimatic® 255 | 907728 | Auto-Line™ 208–575 V, 50/60 Hz |
| Multimatic® 255 with Running Gear | 951767 | Includes Multimatic® 255 (907728) and single cylinder running gear (301449) |
| Multimatic® 255 with Dual Cylinder/TIG Kit | 951768 | Includes Multimatic® 255 (907728) and dual cylinder running gear (951769) and TIG kit (301518) |
| Accessories | ||
| EZ-Latch™ Single Cylinder Running Gear | 301449 | Running gear with single cylinder rack |
| EZ-Latch™ Dual Cylinder Running Gear | 951769 | Running gear with dual cylinder rack and elevated gun and cable rack |
| EZ-Latch™ Dual Cylinder Rack with Elevated Gun and Cable Rack | 301481 | Upgrade single cylinder rack to dual (included with EZ-Latch dual cylinder running gear) |
| Protective Cover | 301521 | Features side pocket |
| Argon/Mixed Gas Regulator and Gas Hose | 195050 | Gas regulation kit |
| MIG Guns | ||
| MDX™-250 MIG Gun with MDX™ Heavy Duty Consumables | 1770043 | 15 ft. (4.6 m), 250 A, .035/.045 in. (0.9/1.2 mm) wire |
| MDX™-250 MIG Gun with MDX™ Standard Duty Consumables | 1770035 1770037 | 10 ft. (3 m), 250 A, .030/.035 in. (0.8/0.9 mm) wire 15 ft. (4.6 m), 250 A, .030/.035 in. (0.8/0.9 mm) wire |
| Spoolmatic® Spool Guns | 195156 130831 | 15 ft. (4.6 m), 200 A, .030–.047 in. (0.8–1.2 mm) for aluminum 30 ft. (9 m), 200 A, .030–.047 in. (0.8–1.2 mm) for aluminum |
| Spoolmate™ 200 Spool Gun | 300497 | 20 ft. (6 m), 160 A, .030–.035 in. aluminum, .023–.035 in. steel/stainless |
| TIG Accessories | ||
| Multimatic 235/255 TIG Kit | 301518 | Complete kit with Weldcraft A-150 TIG torch, foot control, and adapters |
| Wireless Remote Foot Control | 301580 | Foot control with wireless 90 ft. (27.4 m) operating range |
| RFCS-14 HD | 301589 | Heavy-duty foot control |
| RCC-14 | 151086 | Fingertip control (East/West) |
| RCCS-14 | 043688 | Fingertip control (North/South) |
| 10-Pin to 14-Pin Adapter Cord | 301545 | Enables standard 14-pin TIG remote controls for Multimatic 255 |
Contact us
- Miller Electric Mfg. LLC An ITW Welding Company 1635 West Spencer Street P.O. Box 1079 Appleton, WI 54912-1079 USA
- Equipment Sales US and Canada Phone: 866-931-9730
- International Phone: 920-735-4554
- MillerWelds.com
Documents / Resources
 | 255 MIG Multi Process Power Source |
References
- millerwelds.comwww.millerwelds.com
- User Manualmanual.tools