In the early 1970s, the electro-geometrical method was used to shield power lines from lightning. Fortran IV; CDC CYBER 176. In small substations, masts or rods erected at the corners or columns shield the buses and apparatus falling within their protective cones (Figure 5). The ground wire’s protective zone is the volume between the base plane cbc and the diagonal planes ac, extending from the ground wire to the object’s plane. Fuel savings, emissions reductions, noise abatement, and safety aspects are the main focus here. When the circuits share the same ground wire, the circuit currents that flow through the finite impedance of the common base line may cause ground potential variations on the other circuits. Not all the strikes with peak currents less than I1 will defy the shielding and strike the structures. Figure 25 – Shielding connected to the signal reference potential it protects. This condition is the method’s drawback because field observations on buildings show that most strikes finish on sharp points or projecting corners. The steel structures, circuit breakers, and power transformers lay on concrete foundations buried below grade. The biggest problem caused by EMI is the occasional situations that slowly degrade the equipment and its components. Individual standard conductors that meet the general type specifications concerning temperature, gauge and applicable codes are acceptable, provided they are distant from high voltage cables to minimize the coupling noise. EM shielding (electromagnetic shielding) is the practice of surrounding electronics and cables with conductive or magnetic materials to guard against incoming or outgoing emissions of electromagnetic frequencies (EMF). In distributed systems like industrial process control, with distant physical areas and power supplied by different power sous, it is recommended grounding on each location and to apply EMI control techniques on each signal routing, as shown on figure 2. However, the loops are mostly connected to the ground to prevent shock risks. How to reduce electrostatic interferences: Figure 16 shows the capacitance on the coupling between two conductors separated by a D distance. In fact, shielding and grounding problems are frequently responsible for measurement errors, but many test system developers aren’t quite sure why. After the stepped leader establishes a ground connection, a power return strike moves up the ionized channel prepared by the leader. Arrange the conductors in a way to minimize the inducted current between the sets and and balance them. The Scottish government guidance continues to be that everyone who can work from home, should do so. Common high frequency conductors have the disadvantage of having high impedance and current loops should be avoided. Figure 12 shows that, according to the rolling sphere method, lightning can strike the building with the mesh resting directly on the roof. The “disturber cable” and the “victim cable” are followed by a magnetic field. See figure 33. There are several ways to apply a ground to a shielding network; when dealing with copper shielding foils, the ground wire can be soldered directly to it. Make sure the continuity of the shielded cable is longer than 90% of the cable total length. This is normally achieved by minimal separation the segregated routing of cables. Above kHz: the inductive reactance predominates and this will make the current circulate by the way of less inductance. A distribution of currents occurs here, in function of the frequencies, since the current tends to follow the course of lower impedance. The ground wires, masts, and rods must be connected to the substation’s grounding electrode and the overhead lines’ counterpoise system if any. This would be the ideal condition, one that, however, is not necessarily true in practice. Each local area has a COVID protection level and each level has its own specific guidance on shielding. Figure 9 shows adequate grounding whose individual currents are conducted to a single grounding point. This indicates that those who are shielding (and who cannot work from home) may be able to attend the workplace in all tiers, subject to the workplace being made safe for them - discussed below. MILLIONS more Brits will be plunged into Tier 3 from Saturday, Matt Hancock revealed today. Figure 33 presents wiring, shield and grounding details on multiple areas. This is recommended by all inverter manufacturers. Therefore, only use trained and qualified professionals on installation, operation and maintenance jobs. For unshielded lines, the recommendation is running a ground wire for a distance of at least 1 km to reduce the magnitude of the lightning surges entering through the lines. The cable height in relation to the reference plan (relatively to the soil). A floating shielding does not proctect against interferences. The door hinges will be adjustable in both the vertical and horizontal direction to insure high accuracy alignment of the RCM mechanism. A non-technical dictionary defines the word as a point in contact with the ground, a common return in an electric circuit and a arbitrary point of zero voltage potential. Any shielding through which noise flows must not include the signal path. The geotextile backing is invisible to CP currents because of its open weave. The use of non-magnetic metals around conductors does not shield against magnetic fields. The most common purpose is to prevent electromagnetic interference (EMI) from affecting sensitive electronics. Noise effects can be minimized with adequate techniques of projects, installation, cable distribution, grounding and shielding. In the point‐by‐point mode, the system is first set up at a given frequency without the specimen holder in the line. Significant damages may be caused to active equipment when the ground potential difference between both ends goes beyond 1 V (rms). For those on the Scottish shielding list, the new Scottish tier system includes new guidance. A grounding loop occurs when there is more than a grounding path, which generates undesirable currents between these points. Single-point grounding. Innactive connectors may develop resistance or become RF detectors. The frequency: the inductive reactance is directly proportional to the frequency (XL = 2πfL), The distance between the disturbing and victim cables and the cable lengths running in parallel, The height of the cables in relation to the  plan of reference in relation to the soil, Limit the length of cables running in parallel, Ground one of the shield ends between the two cables, Reduce the dv/dt on the disturber cable by increasing the signal peak, whenever possible (resistors connected in series, PTC resistors on the disturber cable, ferrite rings in the disturbers and/or the victim cable), Limit the cable “h” height to the gound plan, Whenever possible install the cable close to the metal surface. The grounds on the non-safe and safe sides are separated. FIGURE 1: The Zap-X system and its shielding. Shielding must be connected to the ground or the structure compliant to ABNT NBR IEC 60079-14 standard. Figure 24 – Protection of transients with the use of metal ducts. The user is responsible to determine which rules to follow in his applications and guarantee that each device is installed in compliance with them. Make the termination of the inverter power source, motor and terminal block control connections. This year, we’re adding an article on simulating electromagnetic shielding for aeronautical applications. The main effects of inadequate grounding are electric shocks to users through contact, low or intermittent response from the protection systems, such as fuses, circuit breakers etc.). According to the stepping mechanism’s prestrike theory, before the stepped leader reaches the ground, a discharge similar to the leader rises from the ground to meet it. The standards establish the minimum insulation of 500V resistance between the ground terminal, while the system ground must be lower than 1Ω. 1 Multipoint grounding is permissible if connections are made to an equipotential ground plane dimensioned to help avoid cable shield damage in the event of power system short-circuit currents.. 8. Act safely on measurements, avoiding contact between terminals and wiring, as high voltage may cause electric shock. Or, still, the transistor polarization currents may be altered and cause their saturation or cut, or burn its components by the joule effect, depending on the intensity. For microprocessers and digital communication equipment, some industries incorporate or make surges of transient protectors.available. Its use is efficient in differential mode, balanced circuits and has low efficiency in low frequencies on unbalanced circuits. Always ground the motor housing. The resultant shielding might not protect the objects for strike currents I2 < I1 with a shorter striking distance, but will likely guard the items for strike currents I3 > I1 with a more considerable striking distance. Here, only the roof requires shielding. At that point the country then enters into a Tier system but what does this mean for staff that are in the Clinically Extremely Vulnerable category? In practice, it is very common to watch intermittent work and gross errors in measurements due to the bad installations. If we recall that the sphere radius – the striking distance – depends on the projected return strike peak current, and that there is less protection for lower currents, the shielding of structures sensitive to lightning strikes should use small currents and small sphere radius as design criteria. Research indicates that the connection of lightning strikes to the structures depends on the prospective return strike peak current and the structure’s geometry. Remember that the cable between the inverter and the motor presents impedance to the inverter output pulse (called surge impedance). The protective angle and protective zone concept is rather old-fashioned, and methods have evolved to make protection more accurate. The topology and the distribution of the wiring, types of cables, proctection techniques are factors that must be considered to minimize the EMI effects. Watch the cable insulation. To minimize the induction effect use the twisted pair cable that reduces the (S) area and the Vb inducted voltage in function of the B field, thereby balancing the effects (average of the effects according to distances): The twisted pair cable is formed by two pairs of wire. The lowest level is 0 and the highest level is 4. 2. In classified areas, if the equalization potential between the safe and the hazardous areas is not possible, the shield must be connected directly to ground (Equipotential Bonding System) only at the hazardous area side. Do not be neglectful, imprudent, irresponsibly inexpert or incompetent on technical problems. Preferably, the shield must be grounded on two points, a the beginning and the end of the bus, provided there is no difference potential between these points and allows the existence and paths to loop currents. In this case the current will not circulate through the loop and will not cancel the magnetic fields. For masts or rods, the protective angle generates a conical surface protecting items below it. Differential Mode Common Mode Source Victim, Figure 13 – Differential mode and common mode – Capacitive coupling. Substation Shielding Methods for Lightning Strikes, lightning strikes to transmission lines or substations, ReliOn Fuel Cells Complete NEBS Level 3 Compliance Testing, Micropelt Introduces Thermoharvester-Driven Wireless Sensor Node, Increased Power Density and Performance with 3D Embedded Substrate Technologies, Developing Next Generation Energy Management: An Interview with Huw Davies of Trameto, Improving Efficiency with an Active Switch on an AC Bridge, Transformers (power, current, and potential), Auxiliary equipment (such as carrier-current capacitors). Configuration is best suitable for low-frequency spectrum and satisfies perfectly high frequency and inversely to! On both ends to minimize the inducted current between the ground value should be minimized with techniques... Three main reasons to earth a system its components: grounding through structure. 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