Overview of the most popular machines for manual welding:
How to choose a welding inverter?
In this article, we review the models of inverter-type welding machines for the most common type of welding – manual arc welding (or MMA – “Metal Manual Arc”) with piece-coated electrodes.
So, you have made a decision: buy a welding inverter.
How to find an inverter so as not to pay extra money? Which welding machine brand is more reliable?
In this part of the article, you can find answers to the following questions:
Classes of inverters – household, professional and industrial.
How to choose a household inverter?
Will the inverter work in your power grid?
Popular brands and brands – which are better and why, examples. Why is it profitable to buy an inverter in the company “SEVECO-ST”?
In other parts of the article, we will answer the following questions:
- How to use the inverter correctly?
- Popular inverters in 2021.
Choose a professional inverter.
- Selection and features of the power supply network.
- Functional features of inverters.
- Examples of choosing a professional inverter.
A large selection of inverter welding machines( inverter rectifiers), commonly referred to as “welding inverters“, makes the task of choosing an inverter welding machine very difficult for both novice amateur welders and experienced suppliers and specialists with experience.
On our website, in the section Welding Inverters, there are at least 80 different models, and this is far from the limit.
Before choosing a welding inverter, determine the class of the machine.
Field of application of the inverter (Class of the device)
Conditionally welding inverters can be divided into household (amateur), professional (for commercial use), and industrial.
Inverters of household class (hobby class) – welding in domestic conditions (in the country, in the garage).
The quality requirements are standard.
The operating mode is short-term. Such an inverter welding machine is used for a small amount of work or one-time work.
The welding current of the inverter is usually from 120 to 200A.
Professional class inverters – repair of communications, pipes, installation work in housing and communal services, manufacture and assembly of frame structures, etc.
Quality and reliability requirements are high. The operating mode is continuous. The operating conditions are more severe. The welding current of the inverter is usually from 200 to 300A.
Used for commercial purposes.
Industrial-class inverters welding of critical metal structures in the installation of pipelines, in the construction of industrial and infrastructure facilities.
Mode of operation-continuous (shift work
The scope of work is large, and the quality requirements are high.
The welding current of the inverter is usually from 300 to 500A.
Each class corresponds to certain tasks, the quality, volume and duration of welding work, and the operating conditions of the inverter welding machine.
Directly from the class of the device depends on its price and reliability.
The methods for selecting an inverter will be different depending on its class.
Choose a “household” welding inverter
You can use a simple algorithm: power selection (welding current), network parameters selection, and price (manufacturer, brand).
THE CHOICE OF CAPACITY (RATED WELDING CURRENT) INVERTERS
For welding with a 3mm electrode, the optimal welding current is 90-110A. However, it is worth choosing an inverter with a rated current of at least 160A to have a current margin in the range of 30-50%. Why is this necessary?
The rated welding current is the current at which the inverter welding machine will operate without overload, will not overheat, taking into account the duration of the load ,PN %, i.e. in the repeated-short-term mode.
As a rule, this is the maximum current for this device.
The rated welding current can specify in the operating instructions of the welding inverter.
It should be considered:
- operating at the maximum welding current may cause the inverter to overheat and fail.
- when the mains voltage is reduced to 170-180 V, the power of the inverter usually drops and the welding current will be lower than the rated one.
- when using long welding cables (more than 5m), the power of the inverter drops and the welding current will be lower than the rated current.
when using network cables with a length of more than 15 m, especially small cross-sections, the voltage at the input of the inverter will be lower and the welding current will also be lower than the rated one;
a number of manufacturers overestimate the passport data of the current and PN%, as a result of which the inverter does not provide the necessary current, works with overload, overheats and fails.
As a rule, an inverter with a rated current of 160A or 200A is sufficient for welding in everyday life.
Will the inverter work in your power grid?
Determine what your power supply network is:
Stable stationary 220V network: (with a slight deviation of the mains voltage from the nominal value within ± 15%).
These are urban or industrial power grids.
Most models of inverter welding machines remain operational with voltage deviations in the range of 220 V ±15-20%, and with a larger drop, they can turn off or operate unstable.
Unstable 220V network: (An autonomous electric generator or a stationary 220V network, with a significant deviation and power surges in the range of-30% ±20%: in rural areas, gardening, garages, etc., when using network extensions of more than 50 m).
If the utility voltage is chronically low, choose the model of the inverter in the manual which explicitly provided for a range of supply voltages, at lower voltages, the ability to work from the generator.
For more information about choosing an inverter for an unstable network, see the section: “Welding inverters for bad networks”.
Cheap welding inverter
Very often, the buyer sets himself the task: “Buy a welding inverter cheap.” The desire is quite understandable, especially when an inverter welding machine is used little or no, or is purchased for a single task.
It is easy to find such a welding machine types, the main thing is not to make a mistake with the choice.
However, when choosing a cheap inverter, you must take into account the available tricks:
Mismatch of passport characteristics (the manufacturer deceives the consumer).
Our service center periodically tests inverters of different brands and can face with the fact that the actual welding current can lower than indicate in the passport.
It is difficult to check this, because the current value on the digital display does not always correspond to the actual one.
Ask the seller about the possibility of demonstrating an inverter welding machine at maximum current and with a maximum diameter electrode.
The 160A inverter should work confidently with a 4mm electrode. The 200A inverter should “cook” with a 5mm electrode.
The name of the inverter and the rated current do not match.
Usually in the name of the device there is a number meaning the rated welding current, for example, Afterburner-200, NEON VD-161. A number of “tricky” manufacturers indicate in the name a number greater than the rated current, for example-Telwin Tecnica 211/S (current 170A), etc.
That is, the device has much less power than its counterparts, but it is cheaper.
Carefully read the operating instructions, especially the data of the PV (%) and the rated welding current.
Such inverters are often sold in regular hardware stores.
At the same time, “sales consultants” advertise typically household appliances as “professional” equipment.
Inverters of unknown brands: Possible risks – low-quality components, low reliability, no real warranty.
The low price of the inverter may hide the actual lack of warranty.
Formally, there is a guarantee, but the repair service has an installation-a refusal of the guarantee under any pretext.
It may turn out that after the warranty expires, no one will take the inverter welding machine for repair. Read reviews on the Internet.
Single-board inverters: They are cheaper. All the main elements – power, control, power-are assembled on one board, the price of which is 80% of the cost of the inverter.
Failure of the inverter due to overheating, power surges, moisture ingress may require replacement of the board and lead to a denial of warranty service.
The cost of repairing single-board inverters can reach the cost of a new device, so some sellers and service centers generally refuse to repair them.
The inverter welding machine becomes “disposable”.
Single-board inverters can be easily identified by the vertically positioned power cable connectors (inserts).
These devices look like this:
Remember, the price of the inverter can strongly influence to the class of the device, the quality of the components, the build quality and the circuit according to which it is made. The price may be low, but the inverter welding machine will not solve the problem.
A welding inverter whose price is significantly lower than the price of its “brothers” can be “disposable” and non-repairable.
Be wary of cheap inverters!
To buy a cheap household welding inverter-follow the PROMOTIONS and SALES!
Choosing a brand of household inverter
In the household class, a large number of welding inverters from China, both well-known and unknown, but cheap.
We advise you to give preference to well-known, proven brands.
They are popular, there are a lot of reviews about them, there are very high-quality models.
“Branded” devices under the brands “SVAROG”, “BARS”, “CEDAR”, are manufactured at large modern factories in China, usually have European quality certificates, and are supplied to Europe and America.
They can supply to Russia for many years and have proven themselves well.
SVAROG Real ARC-200 inverter.
The layout and build quality are at a high level.
They are quite reliable, thanks to the use of components from leading world concerns and high-quality installation.
They are suitable for most standard tasks, there are models for domestic use, and they can supply in a complete set.
Suppliers of these brands have a network of service centers and value their reputation.
These brands are also very popular and can provide with good service.
Additional functions of modern household inverters.
A number of modern welding inverters are equipped with additional functions that facilitate welding.
These functions are more important for novice welders.
ARC FORCE function-stabilizes the arc during welding, prevents the electrode from sticking;
the “HOT START” function – a short-term increase in the current at the moment of arc ignition, ensures perfect arc ignition;
The “ANTI-STICK” function ensures that the welding current can turn off when the electrode is short-circuited (stuck), and prevents the electrode from overheating (claiming) and turning on when the electrode is “torn off”.
Service and Warranty
Find out from the seller the coordinates of the service center and find out whether this model can accept in the warranty, how often the devices can repaire, what are the weak points, what is the deadline for repairs, whether there are spare parts for the selected model.
For some models of inverters, suppliers do not have spare parts.
It is best if the sales company has its own service center.
It is simply unprofitable for her to sell low-quality unreliable devices.
For good reliable inverters, warranty periods of 1-2 years are set today.
Examples of choosing a welding inverter
Welding in domestic conditions (in the garage or in the country, for your own needs).
Details – area, 3mm thick tube with a wall thickness of 3 mm.
Welding mode – short-term (PV=30%).
The network is 220V, the mains voltage is normal, the power cable is not more than 15m.
Welding current – 80-120A.
The electrodes are 2.5 – 3.0 mm.
I’m Sahadat Hossain. I am working as Assistant Professor at Joynagor Technical and BM College. Besides, I have one welding workshop business from 2013. And in 2018 I started blogging about welding accessories. I want to share my experience with using welding accessories. In this blog, all content is written by me.