Limitation of magnetic fields

Following the growing awareness in Israel of the possible effects of magnetic fields on human health, which was also reflected in the Radiation Law 2006 enacted at the initiative of the Ministry of Environmental Protection, measures are being taken to limit the public’s exposure to magnetic fields. The main methods of limiting the level of magnetic fields in modern electrical systems we are increasingly encountering a phenomenon called odd wave harmonics. It is customary to refer more to the third wave, these harmonics are disturbances, sine wave distortion.

The phenomenon is often caused by non-linear consumers, suppliers, computer systems, etc., side effects of these disturbances are causes of a three-phase network complete imbalance and, as a result, an increase in the magnetic flux around the electrical panels.

In electrical planning for multi-consumer electrical panels, there is a special emphasis on reducing the magnetic flux. The Electrical and Electronics Engineering Department, which is shared with the Radiation Protection Engineering Department and is responsible for implementing the physical infrastructure and technical tools for planning the limitation of magnetic fields from various voltage sources:

• Harmonies
• Stray currents detection
• of the power grid
• Power factor test
• Grounding test
• Phase balance

Overload and other electrical tests Electrical quality testing encompasses current and voltage harmonics, power outages, techno-economic considerations, risk assessments for magnetic fields that abound from electrical installations.

Definition of harmonic distortions and percentage of distortions, imbalance, power losses and energy losses in an electrical network, the development of the materials used for shielding in low voltage, high voltage and higher voltage power systems, grounding in low voltage facilities, these are the main steps in the design of low radiation electrical panels.

As part of its policy, the Dolev Group sees great importance in community involvement, and it contributes significantly in the fields of education for advanced technology, believing that technology available to all will contribute to a commitment to a healthy environment.

R&D laboratory at Dolev Clean Environment Ltd. of the Dolev Group

Performs electromagnetic compatibility tests in a Farday cage (Shielded Roors), consulting, and solutions for power quality problems, electromagnetic radiation, wireless communication, electrical appliances and electronics with advanced measuring equipment.

Glossary of Terms

Electromagnetic energy – energy that moves in waves, such as ultraviolet radiation. that can be seen.
Wavelength – the distance measured in the direction of the wave’s progress, from some point to that point in the next instance.
Electromagnetic – magnetic properties created by an electric current.
Ampere – unit of measure of electric current; The amount of current passing through an electric circuit with an electromotive force (voltage) of one volt and a resistance of one ohm. Abbreviated notation is amp or amp.
Radiant energy – all forms of energy coming from the source in the form of waves.
Electron – an intra-atomic particle with a negative electrical charge. Electrons are part of the atom and move around the nucleus.
Uninterruptible Power Supply (UPS) A backup power source that kicks in when a power outage occurs or voltage drops to an unacceptable level. During a power outage, uninterruptible power systems include protection from voltage surges and sometimes even voltage regulation. Small uninterruptible power systems provide energy from a battery.
Electromagnetic waves – radiation containing moving waves of electric and magnetic eddies. Examples of electromagnetic waves are X-rays, light waves and radio waves.
G IRON G IRON
The spectrum of electromagnetic radiation – the name given by scientists to many types of radiation, when we talk about them as a whole. The types of radiation include a long list of frequencies, from radio waves to gamma waves, which are characteristic of light.
Harmonics – the speed regulators that include diodes and power transistors generate high harmonics, noises on the plant’s feed lines, these feed lines carry not only the 50 Hz sine wave but also additional sinuses in multiples of the 50 Hz frequency such as multiple 5 and multiple 7, these harmonics cause damage for electronic systems in the environment and recently also for human health.
Hertz – Hz A unit of measurement of frequency equal to one cycle per second. The electricity grid in Israel is 50 Hz, which means 50 cycles per second. There are also units of kilohertz, (KHz) megahertz, (MHz) gigahertz (GHz) or terahertz (THz).
Induction – the process of creating an electric or magnetic effect under the influence of close proximity to a magnet, an electric current or an electrically charged body.
Volt (V) – International Standard (SI) unit of measure for electric potential or electromotive force. A potential of one volt appears across a resistance of one ohm when a current of one ampere passes through the same resistance.
Watt (W) – the unit of electrical power. One watt is a current of 1 ampere flowing at a voltage of 1.
Alternating current AC – an electric current that changes its direction at fixed time intervals or in cycles; In Israel – 100 changes of direction per second or 50 cycles (frequency – 50 Hz). AC.
Direct current – an electric current that flows in a circuit in only one direction, such as that coming from a battery. DC.
Electricity – a form of energy that is characterized by the presence and movement of electrically charged particles, which are created as a result of friction, inspiration or chemical changes.
Radiation meter – is a measuring device that measures the flux of electromagnetic radiation at different wavelengths.
Certified radiation meter – an engineer certified by the Ministry of Environmental Protection to perform magnetic flux measurements from electrical or communication sources.
Voltage – the potential difference between two conductors, or between a conductor and the ground. It is a measure of electrical energy per electron, which the electrons can receive or give in passing between two conductors.
MU-METAL
SILICON STEEL
Load – the power and energy demands of users from a system of electric power in a certain area, or the amount of power supplied at a certain point.
Kilowatt – a unit of power used primarily for electrical power and energy consumption. One kilowatt equals 1,000 watts.
Radiation – all forms of rapid transfer of energy in the form of particles of electromagnetic waves.
Transmission lines – a system of conductors, insulators, support structures and appropriate equipment, used to transmit large amounts of high-voltage energy, usually over long distances, between generation points and main substations, for distribution to consumers.
Tesla transformer (Tesla) – a device designed to generate high frequency and high voltage electric current.
Transformer – a device that converts the low-voltage electricity produced by the generator to a higher voltage, for transmission to load centers, such as a city, a factory, an office building.

We recommended planning the electrical panels and testing magnetic flux before performing shielding for electrical panels

In three-phase systems, the current flows in the phase conductors, while in conductor 0 the current flows due to a lack of symmetry between the phases, in a network contaminated with harmonics, (see the solution at Dolev Mevhite Clean), the third harmonic and its multiples drain to the zero line. The zero conductor must be used in accordance with the recommendation of CBEMA (Computer Manufacturers Association in the USA b) At the zero line cut at least 1.7 the cross section of the phases even if the phase conductors are not fully loaded. The electrical panels will be designed and built in such a way as to limit the magnetic field from it to a minimum.

The accumulation bars on the board

Phase accumulation strips and the zero accumulation strip will be concentrated together in the upper part of the board, where the distance between them is minimum according to the electrical law. The feed to the board will be in the center and the distribution of the current to the consumers will be symmetrical in terms of the load, on both sides of the feed point.

the magnetic field

The magnetic field from the electrical panel can be limited by several options: phase balance test, harmonics test, stray currents. Arka testing the masking that will limit these magnetic fields.