Power and grounding for audio and audiovideo systems a white paper for the real world by jim brown, k9yc. Victor scuka for his valuable discussion and help during experimental study. What is grounding and why do we ground the system and equipment. No place on earth, that i know of, is completely free of the threat of lightning. Metal frame of the building or structure where the following methods are used to make an earth connection. Grounding from electrical surges is critical for a tower site. Grounding and bonding are fundamental components of power quality and reliability, and shldb b tbf d thi lhould be robust before you do anything else. Tower telco cable tv cold water ground rod s radials grounding is for safety lightning protection blows a breaker if a power system short connections should be big copper and short. However, in the absence of such integrated, distributed and equipotentialized grounding system, a high value of ground resistance will sharply increase the. Earthing systems design steps part one electrical knowhow. Earthing systems for high voltage transmission lines are important for the security of the power system and safety of personal in and around the structures. It also provides for a flow of current that will allow detection of an unwanted connection between system conductors and ground a ground fault. Some object whose potential often 0 v with respect to earth or a power supply is the one to which analog and logic circuits, equipments, and systems can be related or benchmarked.
Touches on lightning impulse characteristics of grounding devices for towers and buildings. Improvements and changes to this manual necessitated by typographical errors, inaccuracies of. Safety from the human, dwelling, and equipment aspects. The major changes from ansitiaeia607 were greater grounding busbar detail, the addition of tower and antenna bonding and grounding recommendations, work area and personal operatortype equipment position grounding and bonding recommendations, and harmonized international terminology although terminology from the nec was retained. Comprises enough material to ground at 1 tower section joint bolt location. They carry not just tv and radio programming but countless telephone signalsordinary phone calls as well as faa air traffic control data, plus police, fire and emergency services.
Practical model for tower earthing systems in lightning simulations. Grounding connections from antennas, cables and shielded wave guides on the tower are made to a. Resources listed under grounding category belongs to technical reference main collection. Ground plates shall be ul listed using copper or copper clad steel plates. Grounding techniques for tactical equipment and systems.
Proper installation of appropriate grounding systems requires knowledge of the needs and layout of the facility. Groundinggg and bonding in communications systems david brender copper development association inc. Grounding considerations for transmission line protection. Protective grounding standard introduced in revision g with the introduction of revision g of the ansitia 222 standard for antenna supporting structures and antennas, effective january 1, 2006, the standard for protective grounding has increased the minimum number of ground rods required and has set a maximum number of ohms of total ground resistance. This value is almost always resistive, though complex counterpoise grounding systems may introduce some reactive impedance. System grounding, or the intentional connection of a phase or neutral conductor to earth, is for the purpose of controlling the voltage to earth, or ground, within predictable limits. An earth grounding system helps to keep the electrical potential on noncurrentcarrying metal surfaces at a similar level as that of the surrounding earth. Each guy point needs to be grounded, as well as the tower base itself. Where the halo ground is attached to exit ground wires, these wires will be solid, tinned, bare copper, number 2 awg or larger. Grounding and bonding grounding and bonding are fundamental. It may be what you cant see that keeps you grounded. One grounding system must be formed interconnecting all other site grounds.
Antenna system bonding and grounding requirements in the usa. It also provides for a flow of current that will allow detection of an unwanted connection between. Grounding of industrial and commercial power systems green book 4. All communications systems need antenna towers, which naturally invite lightning strikes that can cause damage to a centers sensitive equipment. During normal conditions, each tower can be properly grounded to earth with. Sabre product catalog sabre site solutions corporation. We offer a comprehensive components and site hardware catalog that supplies the wireless industry with everything from antenna mounting systems to preengineered lightweight towers. Amateur radio station grounding and lightning protection. An earth grounding system helps keep the electrical potential on noncurrent carrying metal surfaces at a similar level as that of the surrounding earth.
While written for sound and video contractors, the fundamentals also apply to hams. C transmission line standards steel and concrete pole structures overhead ground wire assembly 76. Practical systems will be something of a compromise based on home layout and available. They are also useful in the case of modifications and upgrades to existing substations, which will have extensive grounding systems already installed. The grid under the reflecting pool and around the walkways was constructed using a number of burndy brand grounding products from hubbell. The book will also better equip postgraduates, senior. The standards and guidelines in this revision of this manual shall apply to new. Transient response of grounding systems caused by lightning. Pdf lightning protection scenarios of communication. A complete grounding system for the antenna, towers, and buildings are provided.
Tom rauch w8ji has excellent pages on station grounding. Thottappillil, modelling the lightning current distribution in the shields of cables and the grounding wires. Using formulas, such as from 5, the combined resistance of a tower earthing system and soil resistivity taken from measurements can be calculated. Grounding products and systems technical section69 80 ph. The results, computed considering a typical wind turbine grounding system configuration, provide more insight on the nature of the earlytime transient response of grounding systems and allow to.
There are essentially two reasons for preferring a hybrid grounding system. Rohn bgk3g tower base section grounding kit primarily for 25g and 45g rev. Thottappillil for giving me the opportunity to work on transient response of grounding systems caused by lightning. His skillful guidance through various problems and full support during my studies has been an important backup for my work.
Grounding, lightning protection and surge protection energy. Manufacturers installation standard for lightning protection systems using early streamer emission air terminals hbp21 1. For effectivelygrounded systems this ratio is usually at least 60% 2. Grounding and lightning protection are critical to the safe and legal operation of an amateur radio station.
W5bwc electronics 9108 fm 1972 gilmer, tx 75645 8111. Pdf improved grounding can be a costeffective method to improve power quality by reducing the number of. Ideally the transmission line tower would be perfectly grounded. Its important to take every precaution to avoid accidents, and saferack makes that easy. Tower grounding bond coax shield to the tower at top and bottom keeps coax at the same potential as the tower prevents arcover between coax and tower from lightning arcover fries the coax or hard line at points where it occurs run coax and other cables inside the tower. The general principle in grounding vaisala weather station systems and masts is to install a lightning protection system, including an air terminal, down conductor, and a ground electrode, and ground the mast and the electronics enclosure with separate wires. Electric power system grounding 3phase power systems reasons for grounding and bonding substation, transmission, and distribution grounding power faults and lightning strikes fault current distribution ground potential rise gpr touch and step potentials safety 2 d ng. There are also a number of misconceptions that affect how a ground system works. Presentation outline electric power system grounding 3phase power systems reasons for grounding and bonding substation, transmission, and distribution grounding power faults and lightning strikes fault current distribution ground potential rise gpr touch and step potentials safety 2 d ng.
Sabre has been providing quality products at competitive prices for more than 30 years, and sabre site solutions strives to continue that. A conducting connection, whether intentional or accidental, between an electrical circuit or. This is a discussion of the basic principles behind grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers. A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth. From there, two heavygage copper downconductors lead to a ring ground buried around the towers base. K transmission line standards weathering steel and concrete pole structures grounding details 74.
As a comprehensive treatment of the topic, methodology and technology for power system grounding is ideal for engineers and researchers in power system, lightning protection, and grounding. A complete grounding system for the antenna, towers. Two or more rods grounding systems in ringradial or special set up ieee standard 1100 1 ohm 125vac lg usa 0. Its fun to look at, has great sound effects, and makes. Pdf grounding of overhead transmission lines for improved. Our technologically advanced grounding monitor verification systems help boost both safety and productivity. The choice of earthing to one point on each system is designed to prevent the passage of current through the earth under normal conditions, and thus to avoid the accompanying risks of electrolysis and interference with communication circuits earthing may not give protection against faults which are not essentially earth faults i.
Grounding electrode system and grounding electrode conductor part iii znec 250. Article 810 refers to article 250, grounding and bonding, so i also will discuss its associated requirements. Pdf lightning protection scenarios of communication tower. The national electrical code covers the aspects of antenna. Antenna system grounding by larry d barr, k5wlf intro.
Electrical earthing, grounding, methods of earthing, types of earthing, components of earthing and its specifications in respect to electrical earthing for electrical installations. Washington towers signals from the mountains antennas reach an area covering much of northern new england. Grounding systems shall be installed in a neat and workmanlike manner nfpa 702005, article 110. Thottappillil, grounding resistance calcu lations for the swedish railway communication tower, technical report for banverket project. Any grounding electrode added for communications systems is required to be bonded with a 6 awg or larger conductor to the building or structure grounding electrode system in accordance with 800. To connect the metallic conductive parts of an electric appliance or installations to the earth ground is called earthing or grounding. This chapter discusses the purpose of grounding systems and the various key components used with earth grounding. What is grounding and why do we ground the system and. The influence of pl asmt and particulate on the system was analyzed and the effects of static buildup on the. Asbuilt drawings are often acquired and are useful for towers with existing grounding systems. Pdf transient behavior of wind towers grounding systems. Guide to grounding systems electrical engineering portal. Southeastern towers grounding system design and installation. Telecommunications engineering and construction manual.
Electrical grounding articles here is the article you were interested in if you have any questions about electrical grounding please visit our ask the experts blog and feel free to submit a question. Principles of electrical grounding john pfeiffer, p. Grounding systems and techniques category is a curation of 38 web resources on, safe,effective grounding, notes on ground systems, grounding and reducing noise. Technically, because of the redundant grounding at the many steel towers the foundations of the steel towers serve as redundant grounding electrode systems along the length of this static groundwire. Power, grounding, bonding, and audio for ham radio safety. Guyed towers make grounding a little bit easier, since the guy wires tend to divide up the electrical energy of a lightning strike. The average ham cannot usually implement an ideal ground system. These include internal and external grounding systems for equipment in the communications buildings, grounding of the antenna towers and guys, transmission line, telephone line and ac power line grounding, and grounding of the communications facility. Pdf lightning protection scenarios of communication tower sites. Purpose of grounding the utility power distribution. A tall tower, above the 150 foot point, should have coax cable grounding kits spaced. Grounding of a 230 kv transmission line over a limestone ridge. Bond 3phase power systems neutral ground neutral bond winding 2 winding 1 winding 3 wye to the load l l l n grounding. To connect the metallic conductive parts of an electric appliance or installations to.
Unbalanced neutral currents flow through the earth connection. Antenna system bonding and grounding requirements in the. Grounding and bonding hilosophy was outlined for the electrfcal systems and electronic compartments which contain highvol tage, highpower electrical and electronic eqbiqment. Manufacturers installation standard for lightning protection. A properly grounded site can extend the life of your tower and its components, minimizing downtime and saving you money.
Grounding systems are critical when loading and unloading petrochemical or other harsh liquids. Electrolytic grounding rod systems requirements and use of ground plate electrodes are as follows. Methodology and technology for power system grounding. C transmission line standards steel towers overhead ground wire assembly 75. Take the coax cables to the base of the tower and ground the shields there. Earth grounding is only part of the overall ground system. Technically, because of the redundant grounding at the many steel towers the foundations of the steel towers serve as redundant groundingelectrode systems along the length of this static groundwire. This value is almost always resistive, though complex counterpoise grounding systems may. Grounding is the intentional connection of the electrical system to the earth or a body that serves il fth thin place of the earth. In any discussion of the grounding of electrical systems, particularly as it applies to power systems, there also needs to be a consideration of how the grounding system relates to overcurrent protection. Article 250 grounding and bonding mike holt enterprises.
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