Power Source

SMAW / MMA  Digital Welding Inverters

Sigma Weld series welding machines are so sophisticated IGBT based inverters with total digital control having wide current range.

Sigma Weld is designed to meet varied requirement of the welding industry covering Manual Arc Welding, TIG Welding, High Frequency TIG Welding. Advanced micro controller technology enables Sigma weld to have UpSlope DownSlope and pulsing even without the use of high Frequency.

Features :

1. Constant Current Output Provided

The output of sigma Weld welding inverters are constant even if there is a power fluctuation in the mains of upto +/- 15%. The power of source works equally well with Generator Sets with balanced load. The output current does not drop even at 100 meters of Copper cable length.

2. Energy Saving, VRD Inbuilt

When the oprerator is not welding for more than 2 minutes, the power source automatically switches to low ocv outpput below 24V for safety of operator. This also lead to saving of no load losses.

3. Excellent Welding Performance in MMA for all alloys

The optimized design along with added features like Adaptive Hot Start, Arc Force Control, helps achieve seamless beads with all streels and alloy steels. welding with all types of electrodes such as 6013, 7018, SS308, or 6010 is also possible with ease.

Machines, Electrodes & Current Selector Guide

Sigma Weld Electrode Rutile Basic Cellulosic
Model Φ Amps Amps Amps
SW 170 MMA 1.6 30-35 50-75 20-45
SW 170 MMA 2.5 50-100 70-120 40-80
SW 170 MMA 3.15 80-130 110-150 70-120
SW 250 MMA 4.0 120-170 140-200 100-150
SW 400 MMA 5.0 150-250 190-260 140-230
SW 600 MMA 6.3 220-370 250-320 200-300

Protections and Safety

Sigma Weld welding inverters are designed for Safety of both operator and machines, It has inbuilt protections for Overvoltage, Undervoltage, Output Short, Thermal Overload and IGBT Peak Current locking. This ensures longer life of equipment and our inbuilt Voltage Reduction Circuit which ensures OCV as low as 24 Volts or below when not welding keeps operators safe.


Specification 170 MMA 250 MMA 400 MMA 600 MMA
Rated Input Voltage 1φ, 230V ± 15%, 50HZ 3φ, 415V ± 15%, 50HZ 3φ, 415V ± 15%, 50HZ 3φ, 415V ± 15%, 50HZ
Power (KVA) @ 100% 3.8 KVA 7 KVA 16 KVA 22 KVA
Duty Cycle @ 400C 100% @ 130A 100% @ 200A 100% @ 300A 100% @ 400A
Open Circuit Voltage 80V 80V 80V 80V
Output Range 5-170Amps 5-250Amps 5-400Amps 5-600Amps
(D x W x H) mm 190 x 400 x 280 320 x 460 x 560 320 x 460 x 560 320 x 655 x 650
Weight 10 Kgs 35 Kgs 39 Kgs 50 Kgs

Protection, Safety Features

1) Thermal Shutdown Inbuilt(Over temperature Indication)
2) Under Voltage Inbuilt(Over temperature Indication)
3) Over Voltage Inbuilt(Over temperature Indication/MOV)
4) IGBT Peak Current In Built
5) Energy Save In Built
6) Cooling Type Forced Air Cooling


1) Air Force Control Auto Adjusted
2) Arc Breaking Control In Built
3) Hot Start Current 30%
4) Hot Start Duration(approx.) 300 m sec
5) Digital Ammeter & Voltmeter In Built
6) Process Memory Recall In Built

Optional Accessories

Operating Panel

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