ADVANCED POWER SOURCES LIMITED

How to Choose a Welding Machine?

2 STEPS to choose the right welding machine for your application are:

1) Choosing the right welding process

2) Understanding Input and Output Power requirements and machine size for your needs.

1. Choosing the Welding Process...

There are various types of welding processes, each having its own advantages and disadvantages. The most common welding process are Shielded Metal Arc Welding (MMAW / Stick Electrode Welding), Gas Tungsten Arc Welding (TIG / GTAW), Gas Metal Arc Welding (MIG / MAG / GMAW).

Points to note while selecting a machine:

  • MIG Welding and Flux Core Arc Welding (FCAW) can be performed on same machine.
  • TIG Welding (GTAW) machines can usually perform Arc Welding (MMAW / SMAW).
  • Multi Process welding machines can perform multiple types of welding process.
  • Multi Operator Welding machines can perform one process only but with 2 or more operators simultaneously
 

Following is the ready reference chart while selecting a process between SMAW (Arc/Stick Welding), GTAW (Tig Welding) and GMAW (Mig Welding) welding process types:

Details of each Welding Process

SMAW (Arc / Stick / MMA Welding)

Arc / Stick electrode welding is a manual welding process where in a welder uses a consumable shielded electrode for welding.
Metals: Steel, Stainless Steel, Nickel Alloys and Copper/Brass.
Welding Speed: Slow
Welder Skill: Moderate
Applications: Welding in windy and outdoor conditions. More tolerant to rusty metal compared to other process.
Standard Equipment: Welding Machine, Electrode Holder with Cable, Earthing Clamp with Cable.

GTAW (Tig / Argon Welding)

TIG welding is a manual welding process where in a welder uses a TIG torch with non consumable Tungsten electrode and manually feeds consumable rod in the weld pool.
Metals with AC: Aluminum and Magnesium Alloys
Metals with DC: Steel, Stainless Steel, Titanium, Nickel Alloys and Copper/Brass.
Welding Speed: Low
Welder Skill: High
Applications: By far the most clean and precise welding process available today. Use in application required very good appearance and aesthetic value.
Standard Equipment: Welding Machine, Tig Torch, Earthing Clamp with Cable, Shielding Gas Cyclinder, Gas regulator, Gas flowmeter, Gas Pipe. Liquid cooling system required for high current / thickness application using Liquid cooled Tig Torch.

GMAW (Mig / Mag Welding) / FCAW (Flux Core Arc Welding)

MIG/MAG welding is a semi automatic welding process where in a welder uses a MIG torch/gun which feeds the consumable wire electrode and delivery power from the power source to the weld metal.
Metals - MIG/MAG: Steel, Stainless Steel, Aluminum, Nickel Alloys and Copper/Brass.
Metals - FCAW: Steel, Stainless Steel.
Welding Speed: High
Welder Skill: Low
Applications: Its an easy process to learn with very high speed of welding compared to arc and tig welding. Make clean welds with no slag while welding with gas. FCAW creates slag but is better suited for windy areas.
Standard Equipment: Welding Machine, MIG Torch, Earthing Clamp with Cable, Shielding Gas Cyclinder, Gas Preheater, Gas regulator, Gas flowmeter, Gas Pipe. Liquid cooling system required for high current / thickness application using Liquid cooled Mig Torch.

SAW (Submerged Arc Welding)

Submerged Arc welding is a semi automatic or completely automatic welding process where in a consumable electrode is fed into the weld pool under a blanket of flux (so the name submerged arc). The flux acts as a shielding material and fuses over the weld metal which can be removed after cooling down.
Metals: Steel, Stainless Steel.
Welding Speed: High
Welder Skill: Moderate
Applications: Its a completely automatic / semi automatic process involving equipment for feeding wire and moving the weld torch. Due to its high deposition rates its a choice for thick metals. The welds are of higher mechanical strength and Xray quality. Welding is more comfortable in operating these machines as the weld arc is not visible.
Standard Equipment: Welding Machine, SAW Welding Tractor/Carriage (For feeding consumable wire and moving the welding head), Welding Cables, Control Panel, Earthing Clamp.
Welding Automation products like Column and Boom, Welding Positioners, Rotators are also used to perform welding.

Details of each Cutting Process

Plasma Cutting

Plasma cutting is a process of cutting electrically conductive material by using accelerated jet of hot plasma.
Metals: Steel, Stainless Steel, Aluminium, Copper/Brass, Eletrically conductive material.
Welding Speed: High
Operator Skill: Low
Applications: Its an easy process for cutting different electrically conductive metals. Its a choice compared to oxy fuel cutting as it create a very less heat affected zone, preventing warpage of metal.
Standard Equipment: Cutting Power Source, Plasma Cutting Torch, Earthing Clamp with Cable, Air Compressor, Gas Pipe. Liquid cooling system required for Liquid cooled high current torches.

CAG (Carbon Arc Gouging)

Gouging is a process of melting the metal using an electric arc using the energy from a power source, and then removing the material using a blast of gushing air.
Metals: Steel, Stainless Steel, Aluminium, Cast Iron.
Cutting Speed: Thickness dependant.
Operator Skill: Moderate
Applications: It is used in applications where large volume of metal needs to be removed. Also used in cast iron repair.
Standard Equipment: Gouging Power Source, Gouging Torch, Earthing Clamp with Cable, Air Compressor, Gas Pipe.

2. Understanding Power Rating and Size.

Input Power:

TWO important points related to input power to be check while selecting a welding machine.

1) Check the Input Power Rating of the machine. This is specified as Input KVA and also as Max Power Installed in HP. Input KVA is mentioned for two output currents as per rating of the machine. If the output used in practical application is lesser, then the input power consumed by the machine also will be lower. If you are planning to use the machine on a generator power, make sure you have the generator rating at least 1.5 times the Max power installed for safe and continuous operation.

2) Check the type of Phase and Supply Voltage Rating of the machine. Some machines are rated for Single Phase and some from Three Phase. Single Phase is generally used in Residential or low industrial areas. Three Phase supply is generally available in industrial areas only. Also check what is input voltage supply rating. For example, some machine are rate for 415VAC input. The range of input supply is also mentioned in the specification sheet. For example, out model Magnus 400CCCV is rate for 350VAC to 500VAC input voltage. If your line supply rating falls in this rage you are good to go.

Duty Cycle:

Duty Cycle of a machine denotes how long can be a machine used continuously at what output current and voltage. This is as a standard denoted using a 10 minute cycle as a constant. For example if we say a machine is 60% duty cycle at 250Amp 28Volt means that it can run for 6 minutes at 250 Amp 28 Volt before it need 4 minutes to cooled down to be used again. When checking out product specifications, it is important to note both Current and Voltage for a rated duty cycle.

Light Industrial or DIY kind of machines are rated for 20% to 50% Duty Cycle.

Medium Industrial machines are rated for 40% to 60% Duty Cycle.

Heavy Industrial machines are rated for 60% to 100% Duty Cycle.

Size and Probability:

Check if your machine is as per the size / dimensions you expect it for carrying the same. Check if it has handles or eyebolts for lifting. One more point to check while buying a machine is if it has wheels for moving around in your workshop or does it have rubber footing and can be moved only by lifting. These details are mentioned in Mechanical Specifications section for each machine.

You can also check our Accessories like Welding trolley for improving portability and comfort while using the machine.