Electrical panel design training

Electrical panel design
Electrical panel design training is one of the main demands of newcomers and professionals in the field of industrial automation. A very practical topic that requires years of persistence and effort in electrical panel design training.

We make this way shorter for you.

In this article, you will get to know the principles of designing small and large electrical panels.

In general, if we take a brief look at the process of electricity supply systems, electricity is produced from one point and consumed at one point.

LV switchboards are, in a way, the final supplier and distributor of low pressure electricity between consumers, which we will describe.

Definition and role of electrical panels in the industry:

As we mentioned in the article on types of power transmission lines, at the end of the power generation and transmission process, step-down transformers such as 20KV-400V play the role of powering weak pressure panels. The switchboard is a kind of intermediary between the source and the consumer, which generally has several important tasks.

General duties of electrical panels:
1- Distribution of electricity and feeding consumers

2- Protection of consumers and safety of users

3- Optimization and control of consumers and equipment

Description :

1- Power supply and distribution:

In an industrial or residential complex, there is usually one or more electrical inputs (city electricity, generator) that can feed a large number of consumers. It is obvious that we have to spread and distribute the incoming electricity to all consumers. In fact, a switchboard can have one input and many outputs.

The INCOMING power input is considered the main feeder and the input of the switchboard.

The input can be determined according to consumption with any voltage (380, 220, 24, etc.) or with any current (of course, according to nominal standards)


It is an interface between the input and the consumer, which is responsible for the distribution and division of the electric current. Such as copper busbars and terminals that are used only to distribute the load between different appliances.

It refers to the amount of current consumption and output of a system. In general, in this section, the act of distributing or spreading the load between consumers is done.

2- protection

The most important role of the electrical panel is protection. A switchboard must be effective in the following cases:
Protection of human life, protection against the risk of fire, protection of consumers against electrical disturbances, including low and high voltage, overload, short circuit, and any other factors, whether electrical or mechanical. harm the consumer.

In the circuits, in order that the output current of the system does not apply more than the input, and also, each output line does not consume more current than the allowed limit, fuses and protective switches are used inside the electrical panels, which are basically relative to the value The passing current is more than the permissible limit in the circuit, they react and are cut off.

In other words, fuses limit the current consumption and protect the circuit against overload.

The issue of protection is one of the most challenging issues in the electricity industry, and most engineers do their best to design the most appropriate type of protection for consumers.

One of the most important issues that designers and implementers of switchboard systems should be aware of is the way of protection and the way of protection devices.

Therefore, we must first know what equipment each consumer needs and what are the properties of each of these protective equipment so that we can make the right decision regarding the correct design of the electrical panel.

that we say the correct result; This is because in some cases, we provide all the protective equipment a consumer needs, but we will still see it get damaged and burned. This problem can be due to wrong selection and incorrect calculation of protective equipment.

((Never under any circumstances should a consumer be burned or injured.))

You may have the question that because many factors are out of our control, can the consumer be completely protected against various injuries and disorders, or not?

In response to this question, there are two important points:

First, there are a series of mechanical factors that can cause equipment damage.

These factors are created for various reasons and have nothing to do with the electrical sector, but they can be protected with the help of arrangements made in electrical circuits. Such as the failure of a device’s gearbox, which causes the engine to bear extra load and burn. This problem can be prevented if fuses and protective switches are selected and calculated correctly and can prevent the engine from burning. In other words, the destructive effects of mechanical factors appear in the electrical system, so this part can be controlled to some extent.

The second issue is whether the cost required to provide protective equipment is affordable or not.

For example, we use a miniature fuse to protect a light bulb. A miniature alone cannot be the answer to all destructive factors such as voltage fluctuations, in addition to the fact that the fuse is selected somewhat higher than the rated current of a lamp.

To further protect the lamp and prevent harmful voltage fluctuations, we can use the Stabilizer device. This device stabilizes the voltage and corrects noise, which has other advantages.

It is also debatable that considering the high cost of such equipment, is it worth it anywhere? Do buy and exchange

Is it better to buy 2 lamps per year or to buy a stabilizer for millions?

Or in another example; As you know, motor speed control drives can be used to start the motor because they have many advantages, such as protecting the motor against two phases, protecting against overload, controlling the motor speed, starting the motor without primary current, control and command capability. adaptability etc. But the question is, why the motor speed control drives, considering the advantages they have. Not used in any system?

Answer: Because its use in any circuit is not economically viable and as you can see, contactors are still used in most circuits to start the motor.

Of course, what we mean by the above examples is not that there is no profit from using such equipment, because many arrangements and expenses that are made in the matter of protection, safety and foresight, in a long period of time, return the investment to are accompanied

In short, what we mean by these examples is that we are practically, in most cases, dealing with cost, and to a large extent we have to design for it.

The conclusion we get is that in every project, protective equipment should be chosen according to its efficiency, sensitivity and cost, which is an art in itself.

The most important issue is to have the best quality and protection for the cost. Because we have witnessed many times that some devices, although they cost a lot, but do not have the necessary protection and quality, therefore, electrical devices and equipment can be protected to a great extent.

3- Control:

From the point of view of the industry, the discussion of control can be very traditional and old, or smart and modern. Like turning on a lamp with the help of a normal switch or turning it on by controllers such as PLC, in any case, the switchboard is somehow the center. control and protection of our devices and equipment.

The discussion of control in the electrical panel is one of the broadest topics that can be discussed and it is never possible to summarize the discussion of control in one glance, because the control of a system generally depends on several things.

– The need for the system and its protection – Economic costs – Forecasting the needs and development in the future – The needs and wishes of employers

Connection of electrical components
Another prerequisite that we must be aware of in the design of electrical panels is the basics of electrical systems and especially the relationship between electrical components and parameters such as power, current and voltage, because understanding basic and basic issues allows us to It helps in learning. Of course, in this article, we do not intend to fully and accurately express the basic topics and basics of electricity, but we will take a brief look at this topic to remind you.

In general, voltage is a ready-to-consume energy, which is called potential difference and is characterized by the abbreviation (V) or (U) and the unit of measurement of volt (V). Three-phase voltage 380 is the most used in industries. This article means that the potential difference between two phases is 380 volts relative to each other and 220 volts relative to zero.

Voltage alone does nothing, unless it is connected to a consumer and in the meantime, current is established.

Another component is the current, which is known by the letter (I) and the ampere unit (A), and refers to the amount of current consumed by each consumer. From this article, it can be concluded that a consumer has a lot of power.

Because the power component has a direct relationship with voltage and current. The relationship of P=I.V

It is one of the most important calculation formulas that generally shows the power of a consumer.

Now, by mentioning an example, we will examine the meaning of this discussion.

Suppose a person wants to lift a weight, the person has a potential or ready-to-consume force (V), which we consider as voltage, and the weight as a consumer. Note that nothing will be done until the person has touched the weight, ie the voltage alone will not do anything.

After touching the weight, the person’s hand plays the role of the wire or communication cables. By connecting and applying force to release the voltage, the person can lift the weight. Here, the pressure or and bear, the law of flow (1), and the weight of the load, also has the law of power (P). Therefore, the heavier the weight, the stronger and larger the person’s hand and muscles should be. wires and cables also increase)

This article can explain to some extent the relationship between voltage, power and current components with communication cables, cross section and even voltage drop.

Our most important discussion about the design of low voltage switchboards is about the current component, because the voltage quantity is almost constant and the power component is also obtained from the multiplication of these two parameters.

Therefore, in weak pressure systems, the flow component is discussed a lot, from the discussed topics, it can be concluded that there should always be a balance between the input flow and the output flow, for example, from a meter (input ) with the ability to pass a current of 100 amps, you should not expect a consumer to feed 200 amps, because it will cause fuses, wires, input cables to burn or damage the main networks.

In every industry, especially in the electrical industry, one of the most important and influential topics in design is knowing the equipment used in that industry and the characteristics of each of them. Because if we do not have enough knowledge about each of the electrical appliances and we are not aware of what each of these appliances are made for and what are the properties of each one, we cannot be successful in designing and implementing electrical panels.

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