Linlong Welding · Series selection guide
Linlong MIG400GFW / MIG500GFW Three-Phase Industrial MIG/MMA Welders
Linlong's MIG400GFW and MIG500GFW are 380 V three-phase MIG/MAG power sources with a stick mode, rated 60% at 400 A or 500 A and 100% at 310 A or 387 A. They weigh 105 and 110 kg, and neither the wire feeder nor the torch is described, so get a full packing list before comparing prices.
By WeldOrigin Editorial · Sources checked
What the manufacturer publishes
Values as the manufacturer publishes them for this model, with the source for each line.
- Supply
- Three-phase 380 V ±15%, 50/60 Hz [1]
- Duty cycle (40 °C, 10 min)
- MIG400GFW: 60% at 400 A, 100% at 310 A. MIG500GFW: 60% at 500 A, 100% at 387 A. One set of figures for both processes [1]
- Current ranges
- MIG400GFW: MIG 50–400 A, MMA 40–400 A. MIG500GFW: MIG 50–500 A, MMA 25–500 A [1]
- MIG voltage range
- 15–38 V (MIG400GFW); 15–45 V (MIG500GFW) [1]
- Rated input
- MIG400GFW: MIG 16 kW / 26.2 A, MMA 16.9 kW / 27.7 A. MIG500GFW: MIG 22.9 kW / 37.5 A, MMA 23.5 kW / 38.5 A [1]
- Open-circuit voltage
- 65 V and 75 V printed, with no model or process assigned to either [1]
- Consumable sizes
- Wire 0.8 / 1.0 / 1.2 / 1.6 mm; electrodes 1.6–5.0 mm [1]
- Efficiency and enclosure
- Efficiency at least 85%; power factor 0.93; IP21; insulation class F; fan cooled [1]
- Weight and carton
- Net 105 / 110 kg; gross 141 / 146 kg; one carton size, 960 × 415 × 815 mm [1]
- Listed features
- MIG/MMA, VRD in MMA, 2T/4T, polarity changeover, overcurrent, overheat and undervoltage protection, separate digital current and voltage displays, three-channel airflow [1]
Two heavy three-phase MIG sets with a stick mode
Linlong offers the GFW pair for MIG/MAG welding on a 380 V three-phase supply, with stick welding as a second mode. The MIG400GFW covers MIG 50–400 A at 15–38 V and MMA 40–400 A. The MIG500GFW covers MIG 50–500 A at 15–45 V and MMA 25–500 A.
Both take wire in 0.8, 1.0, 1.2 and 1.6 mm and stick electrodes of 1.6–5.0 mm. The feature list covers 2T/4T trigger modes, VRD in stick mode, output polarity changeover, separate digital current and voltage displays, and protection against overcurrent, overheating and undervoltage. Cooling is by fan through what Linlong calls a three-channel airflow design. Efficiency is given as at least 85% and power factor as 0.93.
These are shop-floor machines for heavy fabrication. For single-phase work at lower currents, Linlong's lighter multi-process machine is the better fit.
[1]Inverter or transformer: ask Linlong to settle it
Buying guidance
Linlong's product title calls the series an IGBT inverter. Yet Linlong files it under its line-frequency gas-shielded category, a term Chinese makers use for transformer-based MIG sets. One design cannot be both. Net weights of 105 and 110 kg are on the heavy side for an inverter of this rating, which sharpens the question.
The answer affects arc behaviour, repair work, spare parts and how the machine copes with supply dips. The efficiency and power factor figures come without a test method. Ask Linlong to state the power stage in writing, send a photo of the main board or transformer, and list the main spare parts with part numbers so a later service order is straightforward.
[1]Sizing the 380 V connection
Buying guidance
At the rated output points, the MIG400GFW draws 26.2 A in MIG at 16 kW and 27.7 A in stick at 16.9 kW. The MIG500GFW draws 37.5 A in MIG at 22.9 kW and 38.5 A in stick at 23.5 kW. Your installer sizes the isolator, fuses and cable from these input figures. The nominal welding current is the wrong number for that job.
Linlong lists 380 V only, with a ±15% tolerance. Many markets supply 400 V, 415 V or 480 V three-phase. 400 V and 415 V sit inside that band; 480 V sits outside it. Some regions also run 220 V three-phase. Give your mains voltage and frequency and ask whether a different tapping or version is needed. Generator use is not covered, so if a site set will power the machine, ask Linlong for its minimum rating.
[1]Duty cycle, wire size and the torch
Buying guidance
Both models list a 60% point at maximum current and a 100% point, all at 40 °C over ten minutes: 400 A and 310 A for the MIG400GFW, 500 A and 387 A for the MIG500GFW. The table gives one set of duty points without naming the process, so ask for MIG and stick figures separately. Heavy shift welding often runs close to the continuous figure.
With 1.6 mm wire and currents above 300 A, the work is likely spray transfer on thick plate, and the torch tends to become the limit. Many air-cooled torches are rated well below 400 A at 60%. Ask which torch ships, its current and duty rating, and whether a water-cooled torch and cooler are offered. The MIG voltage ranges of 15–38 V and 15–45 V look wide enough for spray work; a trial on your own plate will show whether they deliver.
[1]What comes with the power source?
Buying guidance
Linlong gives net weights of 105 and 110 kg, gross weights of 141 and 146 kg and a single carton size of 960 × 415 × 815 mm for both. Nothing beyond the power source is described. There is no word on whether the feeder sits inside the cabinet or in its own case, how many drive rolls it has, what spool it takes or how long the interconnecting hose package is. The W in the model code is also left unexplained.
At these currents, those items decide whether a machine is ready to weld when it arrives. Ask for a packing list naming the feeder, drive rolls for each wire size you run, torch, earth cable and clamp, electrode holder, gas hose and regulator. If you weld with CO2, ask whether a heater outlet is fitted. Ask too what each carton holds, since two different weights share one carton size.
[1]IP21, airflow and polarity changeover
Buying guidance
Linlong describes the three-channel airflow design as waterproof, dustproof and corrosion resistant. The published protection class is IP21, which covers fingers and vertically falling drips. It offers no protection against spray, rain or fine dust, so keep the machine under cover.
Polarity changeover lets a MIG set run self-shielded flux-cored wire, which normally needs electrode negative, as well as solid wire on electrode positive. Ask how the changeover is made and whether the feeder takes knurled rolls for cored wire. On the stick side, VRD and electrodes up to 5.0 mm suit site repairs; check that the holder and lead are rated for the current you plan to run.
[1]Points to fold into Linlong's written offer
Buying guidance
Have each of these answered in the offer itself before you commit.
The power stage design, with a photo and a spare-parts list carrying part numbers.
Separate MIG and stick duty figures at 40 °C, and which open-circuit voltage, 65 V or 75 V, belongs to which model and process.
The version that matches your three-phase voltage and frequency, and the breaker size it needs.
A packing list covering feeder, rolls, torch rating, cables and regulator, plus the price of a water-cooled torch and cooler if you plan long high-current runs.
[1]Keep the variants separate
Swipe the table sideways to read the quotation checks.
| Item | Published scope | Before accepting the quote |
|---|---|---|
| MIG400GFW | MIG 50–400 A at 15–38 V; MMA 40–400 A; 60% at 400 A, 100% at 310 A; input 26.2–27.7 A; net 105 kg. [1] | Power stage design, and which process each duty point covers. |
| MIG500GFW | MIG 50–500 A at 15–45 V; MMA 25–500 A; 60% at 500 A, 100% at 387 A; input 37.5–38.5 A; net 110 kg. [1] | Which open-circuit voltage applies, and the breaker size required. |
| Stick mode | Electrodes 1.6–5.0 mm, with VRD listed. [1] | Holder and lead rating, VRD default setting and stick duty cycle. |
| Wire feeder and torch | Not described; wire sizes 0.8–1.6 mm listed. [1] | Feeder type, spool size, drive rolls, torch rating and hose package length. |
| Polarity changeover | Listed as a feature, with no detail given. [1] | How the change is made, and whether the feeder suits self-shielded flux-cored wire. |
A useful brief for the supplier
Fill in each item. Ask the supplier to respond against the same specification so two offers can be compared.
- A written statement of the power stage: inverter or transformer
- Packing list with feeder, drive rolls, torch and its rating, cables and regulator
- MIG and stick duty cycles listed separately at 40 °C
- Your three-phase voltage and frequency, and the version that matches it
- Open-circuit voltage per model and per process
- Price and availability of a water-cooled torch and cooler for long high-current runs
- Main spare parts with part numbers
Buyer questions
Is the MIG400GFW / MIG500GFW an inverter machine?
Linlong's title says IGBT inverter, while its product category says line-frequency, which usually means transformer-based. Ask Linlong to state the design in writing. [1]
Can the MIG500GFW weld at 500 A continuously?
The 500 A figure carries a 60% rating. The continuous figure is 387 A at 40 °C over ten minutes, and the table does not split it by process. [1]
Is a wire feeder included?
Linlong describes none. Get a packing list for the feeder, torch, cables and regulator before you compare prices. [1]
Will it run on 415 V or 480 V three-phase?
It is rated 380 V ±15%. 415 V falls inside that band and 480 V falls outside it. Ask for the version that suits your mains. [1]
Which open-circuit voltage applies to my model?
Linlong prints 65 V and 75 V without saying which model or process each belongs to. Ask for the figure for your model in each mode. [1]
Sources
Figures come from the manufacturer's published data, checked on the date shown. Before ordering, ask for a written, model-specific answer on availability, certificates, delivery and warranty.
- Linlong MIG400GFW / MIG500GFW product page · Zhejiang Linlong Welding Equipment
Manufacturer publication · Checked 2026-11-04
Linlong's product page for the two GFW models: a feature list and a specification table covering supply, current, duty, input, consumables and weight.
How we check information · Report a correction · Explore equipment