What are the advantages and disadvantages of a three-phase input

Previously, the three-phase input to the house was not considered in principle, because the loads in the houses were such that the single-phase input was sufficient with a large margin.

But time goes on, there are more and more electronic devices and appliances in homes, and therefore the ability to perform a three-phase input is becoming more and more important.

In this article, I will talk about the main advantages and disadvantages of a three-phase input. So let's go.

Understanding the advantages and disadvantages

Probably most of you believe that if you have three phases at once, then the ability to consume electricity will triple.

This is far from the case. The thing is that the rate of electricity consumption is set by the local sales company, and for a single-phase input, the maximum power bar is set at 10 kW, and for the "three-phase" the ceiling is only 15 kW.

As you can see, it doesn't smell like a threefold increase here. A three-phase bushing has a small advantage only in that it needs a cable of a smaller cross-section for its laying than for a single-phase input.

And this entails a completely logical decrease in the nominal value of the input protective switching device. But this cannot be called an advantage either.

But the input and distribution boards should be (in the case of a three-phase) much larger. After all, they need to fit a three-phase meter and switching devices, and they are much larger in size. And most importantly, they are more expensive than single-phase "brothers".

But still, the three-phase input has clear advantages:

And the most important thing is the ability to connect three-phase devices (boilers, mills, electric stoves, etc.). Many three-phase appliances are not only more powerful, but also more economical than single-phase electrical appliances.

Another significant advantage is that you have the ability to connect voltage-sensitive devices to the "good" phase, where the voltage is equal to 230 Volts.

Thus, you can minimize such a phenomenon as "phase imbalance" - uneven loading in phases or unbalance.

That is, those consumers that are connected to the "bad" phase are forced to or endure undervoltage, as a result of which the lamps do not burn so brightly and the electrical appliances work worse. Or complain to the sales organization and wait for everything to be decided there.

Owners of the "three-phase" can independently check the voltage on all phases (the most common multimeter) and put on the highest quality devices that are sensitive to voltage and not worry.

Well, let's make a squeeze of the pros and cons of three-phase input.

Pros and cons of three-phase

Minuses:

1. In order to switch from a single-phase input to a three-phase one, you need to obtain permission for this from the local sales organization. And to do this, first get technical specifications, fulfill them and arrange everything correctly. And as you can imagine, this all costs money and, moreover, a lot.
2. The conditional minus is also that now you will not have 230 Volts in the dashboard, but full 380 Volts, which you also need to take into account and choose better quality wires with good insulation.
3. Three-phase switching devices are more expensive than single-phase analogs.

Now let's go over the pluses.

pros

1. You have the opportunity to distribute the load on the highest quality phases yourself.
2. You can connect three-phase electrical appliances.
3. You can use wires with a smaller cross-section and, accordingly, switching devices of a lower rating.
4. You can increase (although not much) your power consumption.

So, having studied and carefully weighing all the positive and negative sides of the three-phase input, we can conclude that a three-phase input is necessary when you need to connect three-phase electrical appliances and when you clearly need more power than 10 kW.

In other cases, a three-phase input is not so necessary, and the financial costs make it (input) even less attractive.

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