What voltage deviation in the network is considered the maximum permissible

Mismatch of the parameters of the electric network to the required parameters of the quality of electricity established GOST 32144-2013 "Electric Energy. Electromagnetic compatibility of technical equipment. Standards for the quality of electric energy in general-purpose power supply systems ”negatively affects the operation of electrical equipment. In everyday life, this most often affects the life of the bulbs (they burn out faster), as well as the operation of household appliances, in particular, refrigerators, televisions, and microwave ovens. In this article we will consider the permissible and maximum deviation of the voltage in the network according to GOST, as well as the causes of such a problem.

Norms in accordance with GOST

The maximum deviation (both positive and negative) should not exceed the mark of 10% of the nominal. Total we receive such values:

  • for a 230v network - from 207 to 253 Volts;
  • for a 400v network - from 360 to 440 Volts.

Schedule

As for the permissible voltage deviation from consumers, the GOST states that this value at the points of common connection is established directly by the network organization, which in turn must satisfy the standards specified in these standards.

In addition, I would like to note that during normal network operation, the permissible voltage deviation at the terminals of electric motors is in the range from -5 to + 10%, and other devices are not more than 5%. At the same time, after the emergency mode, it is allowed to lower the load by no more than 5%.

By the way, I would like to additionally note that, according to the norms, the deviation on the power supply source in 0.4 kV electric networks should not exceed the mark of 5%, in fact, as with the consumers themselves. Total, 5% at the source + 5% from consumers, we have 10% of the maximum allowable.

It is important to know about the causes of voltage deviation. So the main reason is the seasonal or daily change in the electrical load of the consumers themselves. For example, in the winter time, all the heaters turn on sharply, as a result of which the power supply parameters drop noticeably. About, what to do if low voltage, we told in the corresponding article!

Negative effect of parameter deviation

In order for you to understand the whole danger of voltage deviation in the network, we provide for reading the following facts:

  1. When the value drops below normal, the service life of the electrical equipment used is significantly reduced and at the same time, the likelihood of an accident. In addition, the duration of the production process itself increases in technological installations, which entails an increase in the cost of production.
  2. In a household network, as we have already said, voltage deviations shorten the life of light bulbs. With a voltage increase of 10%, the life of conventional bulbs is reduced by 4 times.In turn, energy-saving lamps begin to flicker when the voltage is reduced by 10%, which also negatively affects the duration of their work. About the rest causes of flickering fluorescent lamps You can find out from our article.
  3. As for electric drives, due to a decrease in voltage, the current consumed by the motor increases. This in turn reduces engine life. If the voltage is even at insignificant, it would seem 1% higher than normal, the reactive power that the electric motor consumes can increase to 7%.

Light bulb burnout

To summarize, I would like to note that there are several modern ways to solve the problem: reduction of voltage losses in the electric network, which we wrote about in the corresponding article, as well as the regulation of the load on the outgoing lines and substation buses.

So we examined the norms of deviations of the voltage in the network according to GOST. Now you know how low or high this parameter can reach in three-phase and single-phase AC networks!

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5 comments

  • Yuri

    Good afternoon.
    GOST 32144-2013 clause 4.2.2. it is clearly stated that:
    In electric networks of low voltage standard rated voltage
    Unom is 220 V (between phase and neutral conductors for single-phase and four-wire
    three-phase systems) and 380 V (between phase conductors for three- and four-wire three
    phase systems).

    Why do you indicate - 230 V and 400 V? Where did the value of the normally acceptable voltage deviation come from - 5% in the guest this is not mentioned. Here in guest 13109-87 it was indicated.

    To answer
    • OblEnergo

      voltage 400/230 V ± 10% officially harmonized with EU standards. Thus, the normal voltage in the network of our houses and apartments should be in the range from 198 to 253 volts.

      To answer
      • Yuri

        I understand everything, but you refer to this GOST 32144-2013 and state that this guest says:
        “So, the maximum deviation should not exceed the mark of 10% of the nominal. Total we receive such values:
        for a 230v network - from 207 to 253 Volts;
        for a 400v network - from 360 to 440 Volts. ”

        In the Guest, paragraph 4.2.2 is written:

        In low voltage electrical networks, the standard rated Unom power supply voltage is 220 V (between phase and neutral conductors for single-phase and four-wire three-phase systems) and 380 V (between phase conductors for three-and four-wire three-phase systems).

        In medium and high voltage electrical networks, instead of the value of the rated supply voltage, a matched supply voltage Uc is adopted.
        The following standards are established for the above-listed CE indicators: positive and negative voltage deviations at the point of transmission of electric energy must not exceed 10% of the nominal or agreed voltage value during 100% of the time interval of one week.
        Note - The established norms for slow changes in the supply voltage are
        to 1008 measurement time intervals of 10 minutes each.
        Permissible values ​​of positive and negative voltage deviations at points of common
        interconnections should be established by the network organization, taking into account the need for implementation
        norms of this standard at the points of transmission of electrical energy.
        In the consumer's electrical network, conditions must be provided under which the deviations of the supply voltage at the terminals of the electrical receivers do not exceed the permissible values ​​established for them when fulfilling the requirements of this standard for CE at the point of transmission of electrical energy.
        When assessing the compliance of electrical energy with CE standards related to slow voltage changes established in this standard, measurements should be made
        according to GOST 30804.4.30, subsection 5.12, class A, while marked data are not taken into account.
        As for me, you mislead readers, but the fact that GOST 29322-2014 is given a different interpretation, you did not mention anything.

        P.S. They love to write regulatory documents that contradict each other ...

        To answer
        • Admin

          Read carefully what you quote "GOST 32144-2013 ... in Russia should not exceed the mark of 10% of the nominal. (DOT)"

          Does this guest indicate a deviation? Indicated that you yourself quoted this place.

          The text refers to the voltage rating in general? Does not go.
          Here the denomination is indicated as something known, and not the argument that 380 or 400 is correct.

          If we talk about the guests, GOST 29322-2014 - it is called "Standard voltages", while GOST 32144-2013 is called "Electric energy. Electromagnetic compatibility of technical equipment. Standards for the quality of electric energy in general-purpose power supply systems "- is something said here about the norms of voltage?

          What do I mislead readers? What makes you think that I am the author of this article? Why did you bring such a quote here? What do you want to achieve with your comment? And why didn’t they comment on what the commentator named “OblEnergo” answered?

          To answer

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