Need Some Help? 0161 223 1843
Need Some Help? 0161 223 1843
October 15, 2021 4 min read
A BUYERS GUIDE
Stick Welders or MMA (Manual Metal ARC) welders now usually come in inverter guises and as well as different voltages then also can incorporate some form of TIG capacity.
Stick Welders use MMA Rods or Arc welding Rods placed into a crocodile type holder. The MMA rods have a flux on them that protects the molten pool from atmosphere as you are welding. This flux will then form a crust on top of the weld that can be easily peeled off when cool.
The great thing about MMA Welders is that they are highly portable, sop they are great for site work outside. All you need is to plug the welder in to the supply and away you go.
Here we will go through the different options and technical jargon to enable you to make an informed choice.
VOLTAGES
Options for voltages are important to note. A 110v MMA Inverter will not give the same power output as a 230v. The maximum size rod usually that you can usually put down with normal 110v is 3.2mm - 4.0mm. The duty cycle of 100v machines is also reduced. You need t ask yourself the question; have i got access to 16 amp or 32 amp 110 volt power? This will determine what size welding electrode you can run.
110v is normally what professional welders will use on sites as 230v isn't allowed. Some sites will let you use 400v though. the 230V welders are generally used by hobbyists or general fabrication where site work is not needed.
Some welders are Multi-Voltage enabling them to be connected to different voltage power sources. The electronics senses the voltage that's been connected and controls this internally.
WHAT IS DUTY CYCLE?
Duty cycle is basically how long a machine will run for until it overheats. Ive written a separate blog post on this and you can see it here.
Choosing the correct duty cycle for your work is very important, and usually this will be reflected in the price and Quality of the welder, always try to get the best duty cycle you can afford.
WHAT IS ANTI STICK?
Inverters due to the speed of the electronics able you to monitor the arc whilst welding. If the welder can sense the electrode rod is sticking, it will then automatically and momentarily, reduce the welding current tottery to prevent this. An Anti Stick Function is a must have on any stick welder.
Its especially useful when welding imperfect surfaces or difficult welding rods.
WHAT IS HOT START?
The hardest part for any beginner to master when ARC welding is the start. ARC welding uses high voltages typically over 60 volts and this couple with rods sizes between 1.6mm to 4.0mm means that the rod can easily "stick" to the work piece. A"scratch motion is needed to reduce this when starting hence why some welders refer to "scratch starts".
WHAT IS ARC FORCE?
Arc Force is an arc control a little bit like Hot Start except that its used during the welding process in stabilising the arc. It prevents it from cutting out whilst welding and preventing the electrode from sticking to the job by supplying a boost of current if it senses that this is about to happen.
WHAT PFC?
Power Factor Correction is a feature that many high end MMA welders have as it supports the use of extra long mains supply leads. Using long main supply leads with an MMA welder can mean the supply voltage can drop when you arc up. PFC can monitor this volts drop and help reduce any damage to the electronics.
CAN I USE ON A GENERATOR?
All welders, even transformer units can work on generators its just that they have to be big enough to run the welder. Look at the rear of the welder on the name plate and check out its Kw Supply requirements.
The problem with welding and generators, is the shock on the generator as you first arc up.
This creates quick draw for current from the generator just as you strike the arc. If the generator isn't quite large enough to supply this surge then the engine can stall or slow down as the load is applied. Even a larger generator will still get this as the loads applied. This draw for current creates a volts drop as the loads applied and this is what can prove fatal for some inverters.
Most Inverter welders are manufactured to accept and still work with a drop of 10% in supply voltage, this is standard throughout industry. Any more that this or if you keep maxing out on this drop fro prolonged periods could create problems and even cause the inverter to blow. Its therefore very important you understand this when matching your new welder to a generator.
HOW TO WORK OUT GENERATOR SIZE
The most critical figure is the generator’s power output.This is measured in watts (W). Most welders are Kw Kilowatts
CONVERT KVA TO kW
KVA x Power Factor = kW. (Generators have a power factor of 0.8)
CONVERT KW T0 kVA
kW ÷ Power Factor = kVA
So, if the welder you want to power has a total wattage of 10kW, the minimum size generator that you would need would be a 12.5kVA.
ROBUST CASE
Stick welders are generally used in site situations and therefore the casings need to be tough to survive all the bangs and dings its going to get. The cheaper the casing the more likely it is to get damaged and maybe smash electronics. Many manufacturers look at this and design toughness into there design.
The Fronius TransPocket for instance has special hard wearing plastics that sit proud of the control panel offering protection.
The aluminium Cover sides are ribbed inside to provide side impact protection.
If your MMA has small buttons and knobs then this is likely going to be a problem at some stage.
If you need any help or would like to ask more questions please contact us.
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