The main and only function welding cable– uninterruptedly and without loss, deliver electricity to the welding site, where it is converted into heat, which will lead to the melting of the metal and subsequent welding.
The cable consists of two conductors, at one end of which an electrode holder or ground clamp is mounted, at the other ends there are terminals or plugs, as on household welding inverters.
The welding cable must pass the operating welding current with minimal losses. From available materials maximum conductivity for copper. So that the wire itself does not heat up, that is, there is no noticeable voltage drop on it, it must be thick enough (large cross-section).
Welded structures have complex shape, and welding has to be done in different positions. The electrode must freely reach any place in the structure being welded. Therefore, the welding wire must have maximum flexibility and not interfere with the work.
Since there are often metal conductive structures around the parts being welded, the wire must have reliable insulation. In addition, the insulation must allow cooking in difficult natural and industrial conditions.
It must withstand exposure to heat, cold, spilled oil or other lubricant. The conductor and insulation must be resistant to shock, jerking and chemically aggressive environments.
Since during operation the welding wire has to be wound and wrapped many times, it must withstand this. These requirements are met by large cross-section stranded copper wire in a soft, oil-resistant rubber sheath.
Characteristics
Today, they do not produce a universal welding cable that could work in all climatic and production conditions. But they produce a fairly large line of wires that meet the main conditions of a welding cable: minimal resistance and flexibility.
U domestic producers The KG brand means that the flexible cable is made of copper. It is intended for connecting power elements of non-stationary equipment and can be used as a welding cable. In addition, there is a special welding cable KS. By technical specifications they are almost identical.
If the wire is marked KG 1x16, this means flexible power single core cable cross section 16 mm2. Permissible operating current 189 A.
The first number indicates the number of wires, the next two or three numbers indicate the cross-section of the wire. The letters HL indicate that the cable can be used at low operating temperatures down to -60 ⁰C. The additional coating prevents cracking in the cold.
The letter T indicates the ability of the wire to work in conditions high humidity and temperatures up to + 85 ⁰C. In addition, the letter T says that the wire has antiseptic properties and is not afraid of fungus and mold, which is typical for a tropical climate.
The abbreviation KOG indicates that the strands of the welding conductor are especially flexible and allow it to be used in any of the most inconvenient and hard to reach places without causing harm to performance.
This cable provides maximum comfort for the welder. In the welding cable KS, the letter P means polymer coating, HF – voltage high frequency. Choosing such a cable for the inverter will be an ideal solution.
When carrying out welding work in areas of increased fire danger, it is necessary to use an appropriate welding cable.
The KGN marking means non-flammability. The entire KG cable, regardless of climatic version completely sealed, can be used underwater. The only thing that needs to be done is to ensure tightness at the junction of the conductor with the device and the electrode holder.
Types of conductors used
The main types of cables used in welding devices are:
- single-core conductors with a copper current-carrying core made of many thin wires are mainly used for inverters;
- two-core conductors representing the anode and cathode, which provide the use of high-frequency current for and alternating current for cutting metal;
- Three-core conductors are used in automatic welding machines used in the installation of pipelines and other products where an even and high-quality seam is required.
For welding machine The kit includes cables designed for the operating currents of the device. If they are not available, then you need to select the appropriate welding wires.
Paying attention to the maximum operating current of the device. It is indicated in the operating instructions for the device. If the documentation indicates an operating current in the range of 160-189 A, then the welding wire, according to GOST requirements, must have a cross-section of 16 mm 2.
At currents of 240-250 A, a conductor with a cross section of 25 mm 2 is required. When using semi-professional devices with 350-362 A, a conductor with a cross-section of 50 mm 2 is required.
In professional welding machines with maximum operating currents of 437 A or 522 A, it is necessary to connect conductors with a cross section of 70 mm 2 and 95 mm 2, respectively.
Is it permissible to lengthen
It is more convenient to work with a long wire, but it increases the resistance of the conductor and, accordingly, an additional voltage drop occurs across it.
To provide the required current, the device must be switched to maximum load mode, which causes rapid wear of the device. It is possible to lengthen the cable, including the return wire, but replace it with a thicker one with a larger cross-section.
Then the losses on the conductor will not change, but the mass of the cable will increase. Since the resistivity is constant for a particular metal, doubling the length of the conductor will require doubling the cross-sectional area.
In this case, it is necessary to correctly connect the plugs and terminals to the cable. They must be connected by crimping or soldering followed by insulation.
There is no clear unambiguous prohibition on lengthening from manufacturers. Special requirements for ensuring current are placed on electrode holders. However, many experts do not recommend extending the cable, stating that the device may fail, and the manufacturer will void the warranty.
Typically, the length of the welding cable for an inverter welding machine is short - less than two meters. It can be not very convenient to work with such a cable, especially at heights. Most manufacturers do not recommend extending the cable.
What is this connected with? The fact is that during the break welding arc the current sharply drops to zero, and the output voltage, on the contrary, increases abruptly due to self-induction emf. This sudden increase in voltage can break through the output diodes.
Originally in inverter devices used to combat this phenomenon output choke. The task of the choke is to accumulate energy and then immediately release it to form a welding arc, at the moment when the key transistors are closed and no current flows through the primary winding. But in Lately most manufacturers (even the most famous brands), in order to save money and reduce production costs, they exclude the output choke from the design of their devices. Its role is played by welding cables due to their inductance.
At first glance, it seems that nothing prevents in such a situation from increasing the cable length to any the right size. However, not all so simple. The cable has both active and reactive resistance, so there is a drop in the output voltage (and, accordingly, the current flowing through the cable) from the inverter output to the weld pool.
An inverter is a rather complex device; it includes such systems as:
- fast arc ignition,
- protection against sticking of the electrode to the part being welded,
- device for current stabilization at a given value.
This is how these systems work on the principle feedback, that is, the magnitude of the output voltage and current is of key importance. Moreover, it is on the output terminals of the device, and not on the electrode holder. Therefore, a change in the length of the cable and the associated change in its reactance and inductance can disrupt the operation of the entire system, up to the failure of the welding machine.
To manufacture the KG cable, suitable for completing welding devices, current-carrying cores are used, woven together into a wire. They are very thin diameter from 0.18 mm to 0.2 mm, made of copper coated with a thin layer of tin to protect against exposure to air and moisture.
The wire made from such cores is marked. For example, cable KG 1*16 is intended for connection to devices that consume a current of no more than 160A. All welding cables have a durable insulating layer.
High-quality operation of the welding machine within long term operation largely depends on the correct cable selection.
Welding cable characteristics
The wire can be connected to a power supply with constant and alternating voltage. The marking indicates the environment in which the product can be used. cable wire can be stretched not only along the ground in the air, but in fresh and sea water. This is a unique feature of the welding cable. Cable characteristics:
- Strength. Difficult to mechanical influence.
- Resistant to temperature changes.
- Resistant to sunlight.
- Immunity to mold and fungi.
- Has elasticity. Low probability of bending.
Variety
Welding cables are used for industrial applications and domestic needs. It is best to use welding wires for the inverter of the KG brand. This cable is well suited for use in power circuits where there is direct and alternating current.
The marking of the KG-HL cable indicates the possibility of using it in cold conditions. Elastic rubber is used to cover the wire, which does not lose its properties even at very low temperatures.
KG-T – marking indicating increased stability coatings to destruction from exposure to all kinds of mold.
Some welding jobs require constant advancement of the machine and wires. For this purpose, cable brand KOG1 is produced. Flexible cores are used. With such a cable you can work in any hard-to-reach places, easily moving all the equipment without fear of damaging the wire. Current through the cable will flow uninterruptedly.
Design features
Current flows freely through the cable from the network to the point of consumption. This is due to his design features. The cross-section of the conductive copper wires has the shape of a circle. The cable cross-section for a welding machine varies and is measured in square millimeters, but it is always equivalent to 16.
The use of special rubber that does not stick allows you to do without a separating layer. Such rubber is called electrical insulating.
The welding cable can be used for four years without replacement. Using the cable longer than the specified period is risky for people and welding equipment.
If the cable has only one core, then it is possible to extend its service life. The conductors are covered with a silicone rubber sheath. So, if this shell and top insulation are changed, then the product can be used again. It's a lot of work, but the expensive copper strands last longer in this case.
Criterias of choice
You can select a welding wire according to different criteria. Firstly, you need a wire for the welding machine with a cross-section for the holder to match. This means the electrode holder. Secondly, the choice depends on the conditions under which the welding work will be performed. Thirdly, the cable must comply with the technical specifications of the inverter.
For single-phase connection A two or three-core wire is sufficient; for three phases a cable with four or five cores is required. From the passport data you can find out maximum power inverter to determine the cross-section of the welding cable that will be optimal. It is important to select a wire cross-section equivalent to the maximum possible welding current to avoid damage to the unit.
Should I extend the cable or not?
The question is not easy. Manufacturers do not indicate in the instructions the possibility of extending the cable. There is also no ban on these actions. Most experts are of the opinion that extending the wire can lead to damage to the welding unit.
An extended wire allows you to increase the area of the workplace, but a long cable contributes to a loss of voltage and a decrease in current. This is bad for the operation of the inverter, because the smooth operation of all device systems depends on certain current parameters. Current readings are important at the cable terminals on the inverter, not where the cable connects to the network. The arc has good characteristics only when the set current is present. In other cases, it is difficult to control the arc. If you increase the current on the inverter to increase the cable voltage, the device may fail.
There are times when you cannot do without extending the cable. It is recommended to resort to choosing the optimal wire cross-section.
Which section to choose
When choosing a wire by cross-sectional area, do not forget about another indicator. This is the resistance level of the wire. It cannot be changed. The specific volume resistance of the conductor for the material is unchanged.
The cable cross-section and its length are directly related. How many times does the length increase? copper wire, its cross-sectional area must be increased by the same amount.
Doing everything listed conditions, you can safely use an extended welding cable without fear negative consequences. The welding current for the arc will correspond to the required parameters, the unit will operate without excessive load.
Connection rules
The lugs for connecting the cable must be either soldered or pressed. Isolation of connections is mandatory. Only in this case will the operation of the device be uninterrupted.
The wire is connected to the power connectors and electrode holders in reverse polarity. Changing the parameters of the welding current entails a change in the polarity of the connections.
Using welding inverter Cases are not uncommon when the standard power cable does not allow the use of the unit in the area where the parts to be welded are located. It is not always possible to move the structures being welded closer to the welding station.
In such situations, extension cables are used; in everyday life they are called carriers, by analogy with household devices. The difference between them lies not only in the power of the wires used. Carrying a welding inverter, used to connect powerful consumers, differs significantly from household products, and the requirements for it are special.
Carrying a welding inverter in a technical sense is a section electrical circuit between the current source and the consumer. We consider a household electrical outlet to be the current source. The consumer is a welding inverter or other high-power electrical equipment. For a section of an incomplete chain, the usual Ohm's law applies, according to which it is easy to calculate all the necessary parameters.
The carrying length has the maximum effect on the wire cross-section when equal powers consumers.
Wire material. Preference should be given to a material with lower resistivity. Copper meets this condition.
The cable insulation does not affect the resistance, but under operating conditions it experiences mechanical stress and is susceptible to abrasion and fracture. You should choose a wire with a thicker insulation layer. It may be more expensive, but it will last longer, and it is more convenient to work with such a cable; it is less prone to breaking.
The cross-section of the carrying cable wire is selected in accordance with the welding currents used. Knowing the carrying length, voltage and load current, it is easy to calculate the required wire cross-section. Suffice it to recall the school physics curriculum, the electricity section.
When calculating, you should not forget about the voltage drop in the section of the circuit that represents the transfer. It may happen that a voltage drop will create an overload in your home network.
All calculations should be carried out with a 10% power reserve. This will prevent the carrying wire from heating up.
When using long carriers, you should not leave an extra section of wire wound into a coil. One thing to keep in mind is inductance. A reactance will arise in the improvised coil, which will affect total resistance devices.
Included with the welding inverter, you should keep carriers of different lengths. The difference in length should be 10 m or more.
You don't have to bother with short carriers. It is enough to select the required wire cross-section for the current to avoid overheating.
Often a length of 20-30 meters or more is required. , in theory, is a conductor with an active load component. Resistance to him, who remembers from school curriculum, is determined from the simple formula Rpr. = ρ × L / S, and electrical processes obey Ohm’s law. As a formula, you can use its version for an incomplete chain I=U/Rpr. because when using a network connection EMF source does not affect the result.
- ρ – resistivity of the conductor, depends on the material of the wire. From available materials smallest value has copper.
- L – conductor length. In this case, this is our extension cord.
- S – cross-sectional area of the wire. It is indicated on the label.
- U – network voltage 220V. But such a voltage is ideal; it is practically necessary to measure real value. Depends on right choice extension cord
- I – current at maximum load to the inverter.
The formula shows a direct dependence of resistance on the length of the conductor and inverse relationship from the cross-sectional area. And as the resistance increases, the voltage drop across the circuit section increases. That's all the wisdom. The extension cord for the welding inverter should not have a significant effect on the network voltage. The voltage drop across it should be minimal. In any case, the cross-sectional area of the cable should not be less than the cross-section of the wiring in the house. Do not try to use household carriers. Wire size for household appliances choose to the minimum, you can save a lot on expensive copper. From experience we can say that a wire cross-section of 2.5mm2 will ensure safety when welding current up to 170A, provided that the network wiring can withstand it. It is rare that anyone at home is able to work with such current.
I would like to warn lovers of convenience. Do not wrap the extension cord around a reel. Do not forget about the occurrence of induction in ring conductors. If the resulting inductive reactance does not affect the operation of the inverter, then an increase in temperature in the coil, due to additional inductance, can melt the insulation on the wire. If you decide to wind, then do not wind tightly, it will reduce natural ventilation, and therefore worsen the cooling mode.
You should not be afraid of heating the extension cord wires. Normal temperature for wires it is considered 70°C, at this temperature the hand burns, so if the hand can withstand it, the extension cord will not overheat. But if the inverter turns off, then the supplied voltage is too low and the cause should be looked for. It does not necessarily relate to portability; rather, the problem is the low voltage of the supply network.
Explanation of welding cable and extension cords.
Dear customers, in this article we will tell you what length of extension cord you can use to connect welding machine, what kind of extension cord it should be and we’ll give practical advice about this theme.
Wire section resistance:
R – Resistance.
L – Length in meters.
S – Wire cross-section in mm².
P – Resistivity copper (equal to 0.017 ohms multiplied by mm² and divided by meters)
The formula looks like this:
Example:
You take a 30 meter extension cord. Cable cross-section 1.5 mm². The welding cable connected to your machine is 7 meters and has a cross-section of 25 mm².
It turns out R = 0.0017 x (30x2/1.5) – 0.68 Ohm.
U = 0.68 Ohm multiplied by 45 (45 is the maximum current consumption, the Svarog ARC 250 R112 device is taken as an example) and we get 30.6 V.
Thus, we see that if you use a 30-meter extension cord with a cross-section of 1.5 mm², then not 220 V from the outlet reaches your device, but 189.4 V. (220-30.6).
If you take an extension cord with a thicker cross-section, for example 25 mm², then the loss will be less and will be 18.4 V. This means that 201.6 V will reach the device from your outlet (220-18.4).
There is no need to demand the impossible from the device; if you connect a very long extension cord, you must understand that there will be losses in the power of the device. If you plug the kettle into a socket in Moscow, and the kettle itself is in St. Petersburg, then it will never boil.
Let's look at another example. Almost all manufacturers use three-meter welding cables as standard. People often connect very long welding cables to machines.
Formula:
R = 0.017 x (7x2/25) = 0.00952 ohms.
We take a welding cable 7 meters long and multiply it by 2 (the current goes back and forth, so you need to multiply 7 meters by 2) then divide it by the cross-section, let the cross-section be 25 mm². We get 0.00952 Ohm.
And now the second formula.
Let's take 210 A² and multiply by 0.00952 Ohm. We get 420 W. Thus, your device will lose 420 W in power. The thicker the cross-section of the welding cable, the lower the losses. For example, if you take a 35 mm² welding cable, you will lose 300 W of power.
Important!
If you use an extension cord, always unwind it completely. If the extension cord is assembled into a reel, then the cooling conditions worsen, which can lead to fire of the wires or their melting, since the current consumption of the welding machine is higher permissible current extension cord, usually.
Results:
The larger the extension cord, the greater the losses.
To avoid serious losses, use an extension cord with a thick cable section.
To avoid additional losses when extending the welding cable, use a cable with as thick a cross-section as possible.
Another frequently asked question from our customers. How much will the loss be in Amperes if you use a long welding cable? This is very difficult to calculate, since the properties are defined in terms of the current-voltage characteristic. To do this, you need to connect the welding machine to a ballast rheostat and measure Amperes at a given cable length. But in words we can say that when using a good welding cable with the correct cross-section, the losses in Amperes will be invisible. For example, a cable up to 10 meters with a cable cross-section of 25 mm² - you will not feel any losses.
There are two types of typical I-V characteristics of sources: bayonet and flat I-V characteristics. It is different on different devices and different manufacturers. We will try to conduct experiments with different devices and inform you about the results.
Power extension cord for welding machine and inverter on a 30 meter reel.
Extension cord on a reel of 30 meters for a welding machine and inverter. The extension cord's wire cross-section is 3x2.5, allowing the extension cord to be used on a Umelets series reel with almost any welding machine or inverter. A powerful extension cord can withstand loads of up to 5,000 Watts at a current of 16 Amps. Welding household appliances(both transformers and inverters) have approximate power 3.0-5.0KW. The power extension cord on the reel is used at temperatures of +1-+40 degrees Celsius. To work at low temperatures, you should buy an extension cord on a metal reel with a KG wire.
Additional Information
| Weight | 2.5 |
|---|---|
| Size | 30 x 40 x 35 |
Product passport
Power extension cord type UХз 16-004 on a reel
Technical data
The extension cord is designed to connect household electrical appliances power up to 3500 W
electrical network voltage 220 V 50 Hz. The extension cord is operated and stored at a temperature environment from 1 to 40°C and relative humidity up to 80%.
The product is certified.
Certificate No. TS RU C-U.ME64.В.00275
Safety requirements and fire safety. Do not use the extension cord in fire hazardous, chemically active or
humid environments, as well as subject to mechanical and thermal influences leading to destruction of the product.
Certificate of acceptance and sale
Extension cord brand UHZ 16-004 on a reel
Date of issue_____________________
Date of sale_____________________
Warranty
The manufacturer guarantees normal work extension cord within 1 year from the date of sale
subject to compliance with the rules of operation and storage.
The service life of the extension cord is 6 years.
Welding equipment is widely used at home, for which special devices are created that meet the requirements for comfortable home use. The professional field of application also has its own models, and almost always specialists may encounter such a problem as a lack of wire length for work. This situation can be encountered both at home and at work. If with a compact inverter for home you can still go to another place and move it, then with professional equipment This cannot always be done. An extension cord for a welding inverter helps solve this problem. Welding machines have sufficient high power, so switching elements are needed to connect and operate them. These elements will be able to withstand the specified operating parameters. Ordinary ones are not always suitable household networks and extension cords from them.
Classification
There are two main varieties, which differ in both appearance, and according to the characteristics of the destination. In any case, they serve to conduct current. The first extension cord for a welding machine is an ordinary network connection device that helps increase the distance from a stationary power source. The second type of extension cord allows you to increase the size of the wire for the welding machine, which is responsible for conducting the output voltage current, which is obtained after processing by the transformer. This is especially true if the apparatus itself is located permanently at the post, and it is necessary to carry out welding further than is provided for by the dimensions of the post.
Specifications
Each extension cord for a welding inverter can have its own unique characteristics, which depend on the scope of application and are manifested in the form of core diameters, length itself, pin features, and so on.
Calculation example for selecting an extension cord
When calculating which extension cord is needed for a welding inverter, you should understand that, first of all, it is a conductor of an active load, which becomes higher with increasing power.
The resistance of the extension cord can be determined using the following formula R=ρ×L/S. All electrical processes taking place in the system are subject to the basic laws of electrical engineering, in particular Ohm’s law I=U/R. Here the law is taken for a section of the circuit, since even after connecting the electromotive force, it does not affect the result. The symbols in the above formulas mean the following:
- I – maximum current at maximum high load inverter;
- U is the voltage that is obtained from the network, and the real one is taken, not the nominal one, which can differ markedly from the standard 220 V;
- S – cross-sectional area of the cable, which can be found on the marking if there is a ready-made option;
- L – extension length;
- ρ is the specific resistance, which depends on the metal of the cores from which the extension cord is made.
According to the above formula, you can easily see the relationship between the length of the conductor, which is the extension cord here, and the resistance. There is also an inverse relationship between resistance and cross-sectional area. The higher the resistance of the extension cord, the more the voltage across the welding machine will drop.
To correctly calculate what kind of extension cord you need using the above formula, you should decide what amperage you mainly use. Many as well foreign analogues, operate normally at 170 A, although they have a large margin maximum current. Based on this, we can accept the standard position for such parameters for the wire cross-section of 2.5 mm square, which should be obtained according to optimal calculations for such parameters.
Features of choice
The welding leads for the inverter and extension cord should not have a noticeable effect on the supplied voltage from the mains, but should be of adequate thickness to withstand the loads. Thus, everything should be reduced to ensuring that, with a minimum voltage drop, the core has maximum resistance to high power. If you have to determine everything by eye and no precision instruments to measure, it is worth selecting an extension cord of such a cross-section that would be no less than the thickness of the core in the room.
It’s safest to use purchased extension cords that have high-quality insulation.”
With ready-made cables, it is easier to choose what wire cross-section is needed for a welding machine, since they are immediately made according to optimal standards for certain types of equipment.
Proper use of an extension cord
Sometimes, the very advantages for which this device is created can become disadvantages. First of all, you need to pay attention to the fact that the extension cord must be used in a straightened state. Whatever cable you use for the welding inverter extension, it should be positioned so that it does not get twisted. For this reason, it is necessary to choose the length optimally, since otherwise, if everything is wound on a coil or other device, induction may occur that forms in the ring conductors. The resulting inductive reactance may not have any effect on the operation of the inverter, but there remains a risk of the temperature rising to such a level that the insulation on the wires begins to melt. It is not recommended to do full winding, as it reduces the level natural ventilation, and an increase in temperature leads to an increase in resistance.
The average temperature that extension cords can withstand is 70 degrees Celsius. Thus, one can easily determine permissible temperature, because if your hand can withstand the hot wire, then this is quite normal. If there are large overloads caused by the resistance of the extension cord, the inverter may turn off.