UNISON (QINGDAO) INDUSTRIAL CO., LTD

INVERTER MMA WELDING MACHINE
UNMMA-250DE

These heavy-duty, fan-cooled machines feature a 2-PCB design and IGBT inverter control for both MMA and TIG (scratch start) welding.
The machine automatically delivers optimal start and stop parameters based on the operator's set welding current.
An integrated booster circuit provides extra voltage to ensure superior cellulosic arc starts and overall welding performance.
The equipment supports diverse electrode types—including general purpose, stainless steel, cellulosic, and low-hydrogen—across a wide current range.
Built-in Hot Start improves arc striking with challenging electrodes, while Arc Force allows users to fine-tune arc dynamics.
The Anti-Stick feature automatically reduces the current if the electrode sticks, making it much easier to detach from the workpiece.
An integrated VRD (Voltage Reduction Device) enhances user safety by lowering the open-circuit voltage when the machine is not actively welding.

Designs:

UNMMA-250DT

UNMMA-250DT

UNMMA-250DN

UNMMA-250DN

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Technical Data

Parameter	UNMMA-160DE	UNMMA-200DE	UNMMA-250DE	UNMMA-300DE
Mains Voltage (V)	220	220	220	220
Frequency (HZ)	50/60	50/60	50/60	50/60
No-load Voltage (V)	65	65	65	65
Rated Input Capacity (KVA)	6.0	8.3	9.5	10.8
Insulation Class	F	F	F	F
Output Current (A)	20-160	20-200	20-250	20-300
Rated Duty Cycle (%)	60	60	60	60
Dimensions (CM)	401427	401427	401427	401427
Weight (KG)	4.5	5.0	6.0	7.5

Parameter	UNMMA-160DT	UNMMA-200DT	UNMMA-250DT	UNMMA-300DT
Mains Voltage (V)	220	220	220	220
Frequency (HZ)	50/60	50/60	50/60	50/60
No-load Voltage (V)	65	65	65	65
Rated Input Capacity (KVA)	6.0	8.3	9.5	10.8
Insulation Class	F	F	F	F
Output Current (A)	20-160	20-200	20-250	20-300
Rated Duty Cycle (%)	60	60	60	60
Dimensions (CM)	3913.526.5	3913.526.5	3913.526.5	3913.526.5
Weight (KG)	4.5	5.0	6.0	7.5

Parameter	UNMMA-160DN	UNMMA-200DN	UNMMA-250DN	UNMMA-300DN
Mains Voltage (V)	220	220	220	220
Frequency (HZ)	50/60	50/60	50/60	50/60
No-load Voltage (V)	65	65	65	65
Rated Input Capacity (KVA)	6.0	8.3	9.5	10.8
Insulation Class	F	F	F	F
Output Current (A)	20-160	20-200	20-250	20-300
Rated Duty Cycle (%)	60	60	60	60
Dimensions (CM)	401427	401427	401427	401427
Weight (KG)	4.5	5.0	6.0	7.5

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Hot Start

Optimizes arc ignition performance for hard‑to‑strike welding electrodes.

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Arc Force

Adjustable to select optimal dynamic characteristics of welding arc.

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Anti Stick

Automatically lowers current for quick release when electrode sticks to workpiece.

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Temperature Protection

Intelligent thermal protection prevents machine damage caused by overheating.

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Fan Cooling

Efficient cooling system accelerates heat dissipation and extends service life.

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Overvoltage Protection

Safeguards internal components against unstable input voltage surges.

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High Efficiency

High conversion rate, less power loss and improves welding working performance.

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Intelligent Energy‑Saving

Low idle power consumption, improves energy efficiency during long working hours.

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VRD

Voltage reduction device for enhanced operator safety against electric shock.

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Lift TIG

Lift‑start TIG function, scratch‑free arc ignition for tungsten electrode.

Packaging Method

A

individual packing，6pcs/ctn

B

individual packing，6pcs/ctn