Review AP Welding MMA-400 Cheapest 400AMP Welder

[miggie weld]

If you want a 400amp MMA stick welder don't buy this.
I had this welder sent to me to review it's a good little welder been using it for a few months ok for 3.2 rods 7014 6013 but is nowhere near 400amp

 

[Memmeddu]

If you want a 400amp MMA stick welder don't buy this.
I had this welder sent to me to review it's a good little welder been using it for a few months ok for 3.2 rods 7014 6013 but is nowhere near 400amp

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300x33 are 10kW
10kW/230V are roughly 50A
So according with your welder chart , you're lucky if it has 150A
Also with the board I watched the video and it's probably 140A because we haven't thought about the cospy and the efficiency
So maybe it's a real 140A
I have a stamos S-MMA 250 IGBT that says 250A and it has 250A
How I know ?
I used a 4mm E6010 to cut through an H beam the rod was red after few seconds

 

[Zrinko]

Hi,
I have welding machine mma-400-k .
When I'm welding, it is welding with max.current no matter if i change the current.
How can I fix that?

 

[eddie49]

Hello and welcome to the Forum !
It sounds like the inverter control circuit has failed, or a component in the output circuit has gone short-circuit, or there is a fault in the output current measuring circuit ( maybe a current shunt or possibly a Hall effect sensor ).

I'm afraid that amateur repair of an inverter welder is very difficult, if not impossible.
The problem issues include no circuit diagram, high voltages inside ( 325v DC ), high operating frequency, unmarked, unknown, unobtainable components, surface-mount construction, and high component density.
Probably the most you could do is a visual internal inspection. Power off and disconnect the input power cable. Wait a few hours for any voltages held in charged capacitors to decay, then remove the casing. Look for loose or badly-seated plugs and push-on tags, burnt components, loose or corroded connections, "dry" solder joints, and loose screws or bolts on the high-current wires and busbars.

 

[Barking Mat]

That box is half empty!

400 amps off a 220v supply is asking alot!