The geography of the site is considered since the soil resistivity could alter the impedance of the grounding system. Counterpoise correction in clusters so far, we have only considered dimers. Classification of grounding systems fig 6 could be evasive. Engineering analysis of airfield lighting system lightning. The system earthing is so designed that it should facilitate the efficient and quick operation of protective relays in. Counterpoise correction and basis set superposition error.
Maintain lightning and grounding systems specifically identified in table 1 according to the procedures within, or procedures referenced by, this instruction. Grounding system for high resistivity limited area. Counterpoise definitions can be found in dictionaries. A closer look at vertical antennas with elevated ground systems. Lightning and grounding system lyncole xit grounding. Here the focus is on classification of grounding systems with respect to the operating voltage of the system.
Lp consultants international pvt ltd 210,207 views. So the use in a quarter wave ground plane antenna of a system of pairs of opposing radial conductors carrying equal currents in opposite directions such that. Counterpoise systems are substitutes for large rf earthbased ground systems. This type of grounding is performed to airfield lighting, power all voltages and communication systems. Project results determining the portion of the zero sequence fault current that goes into the grounding system during fault conditions is one of. When we look at how the word has been commonly used, we see general use and dictionary. Counterpoise system is not connected to the light bases or to the lighting vault power grounding system series cable is nonshielded in conduit schedule 40 pvc. Parts of the counterpoise kit the cha counterpoise kit is comprised of the following components, see plates 2 and 3. Grounding considerations for transmission line protection. Here is an interesting quotation from laport14 regarding counterpoises. Jul 27, 2018 system earthing is primarily required to ensure that the potential of each conductor of the system restricts to its desired value for which the insulation is provided.
Counterpoise ground system last updated december 03, 2019 ground screen, similar to a counterpoise, at base of mast antenna of am radio station ktbs diagram of counterpoise under the antenna mast of an am radio station. At the manhole structure, the counterpoise and manhole including all metallic parts and ground bus is bonded to three ground rods installed around the perimeter of the structure. Counterpoises can also be a source of frustration, providing poor lightning and safety grounds, encouraging local rfi radio frequency interference, and sometimes creating receiver noise ingress problems. The system earthing is so designed that it should facilitate the efficient and quick operation of protective relays in case of any earth fault. One of three sets of five guy wires, each supporting the apopka tower. A counterpoise is a conductor or system of conductors used an earth or ground substitute in antenna systems. Pdf effective length of counterpoise wire under lightning current. An fcp improves an antenna system by replacing more loss with less loss. Surge protective devices for electrical panels and electronics. However, guy olinger,k2av, has created an alternative the folded counterpoise fcp. In electronics and radio communication a counterpoise is a network of suspended horizontal wires or cables or a metal screen, used as a substitute for an earth ground connection in a radio antenna system.
At no point along the duct bank is the cu conductor bonded to ground rods like the faa counterpoise system. A pioneer in the facility protection industry for over thirty years, lyncole xit grounding has the largest staff of fulltime grounding, lightning protection, surge suppression and lightning warning engineers in the industry that we helped create. Here we connect the galvanized wire with the leg of the tower with the help of galvanized lug and the galvanized lug is fitted with a tower leg with the help of 16 mm dia nut and bolts. Wavier tiers per grounding system provided within table. Although equipment safety grounding and lightning protection can be seen as distinct design functions, for some practices these are combined within the single component of counterpoise wiring. K2av contest scores the loss list your shrinking rf issues and fixes a brief technical report on the fcp the fcp story pdf 2012 ncj article planning place an fcp why use an isolation transformer place an inverted l design an inv l diy. Engineering analysis of airfield lighting system lightning protection. The project objective was to optimize the grounding system design, and minimize the use of counterpoise therein. Counterpoise system and grounding for airfield mike holt. The radio tower specs call for grounding of 10 ohms and the footprint is all sand. It consists of a network of radial copper wires suspended above the ground, connected to the transmitter feedline ground. To connect the metallic conductive parts of an electric appliance or installations to the earth ground is called earthing or grounding. Effective length of counterpoise wire under lightning current article pdf available in ieee transactions on power delivery 202. Original the effect of grounding system modeling on lightning.
Grounding requirements specified in this section may be supplemented in other sections of these specifications. Grounding considerations for line protection joe mooney, jared mraz, david lewis, aaron findley, molli dooley power engineers, inc. Here is the definition of counterpoise appearing in the communications standard dictionary. Protection, grounding, bonding, shielding, and surge protection requirements, dated july 16, 2014. Half your antenna is your radio frequency ground, so dont skimp here. So began 2 years of experimentation on layout, construction, methods and materials to perfect what became the 5.
Principles of electrical grounding john pfeiffer, p. Ensure that user organizations identified in table 1 are aware of their maintenance responsibilities. Methods for improving ground resistancetransient ground. Project results determining the portion of the zero sequence fault current that goes into the grounding system during fault conditions is one of the most important aspects of grounding system design. Continuity of the grounding path shall not rely on water meters or. Grounding electrode system and grounding electrode conductor part iii znec 250. Provide grounding of the entire electrical installation as shown on the drawings and specified herein, and in accordance with article 250 of the national electrical code nec.
Counterpoise around each light baseunit a distance of 0. 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. Pipe earthing and counterpoise earthing 02042019 1. The effect of grounding system modeling on lightningrelated studies. Also, the effect of modeling type of grounding system is considered on the tls. Pdf in a high soil resistivity area, counterpoise wires are applied to decrease the. A tuning circuit is coupled between the counterpoise conductor and a ground. Reducing downtime with our grounding and lightning protection system. Line winder plastic winder used to store counterpoise wire. Allcopper grounding systems end million dollar losses at.
Isolation ring insulates counterpoise wire b from tent peg e and ground. A counterpoise mesh is a closely spaced mesh of horizontal conductors placed at a shallow depth above main grounding system. Earthing of electrical transmission tower electrical4u. In electronics and radio communication a counterpoise is a network of suspended horizontal wires or cables or a metal screen, used as a substitute for an earth connection in a radio antenna system. A closer look at vertical antennas with elevated ground. National electrical code nec as it pertains to lowresistance grounding for lightning protection systems, covering such areas as the following. Counterpoise and rf grounding a mobile antenna nashua area radio society topics in all forums elmering forum counterpoise and rf grounding a mobile antenna this topic has 8 replies, 4 voices, and was last updated 2 years, 4 months ago by tom mahon. Some recommendation are made concerning the use and characteristics of earth electrodes, for example effective counterpoise length, where to locate grounding. Counterpoise wire 25 foot wire for use as antenna counterpoise.
This value is almost always resistive, though complex counterpoise grounding systems may introduce some reactive impedance. System earthing is primarily required to ensure that the potential of each conductor of the system restricts to its desired value for which the insulation is provided. Counterpoise ground system wikimili, the free encyclopedia. Ideally the transmission line tower would be perfectly grounded. Marine grounding systems this article was originally published in the october 15, 1996 issue of practical sailor. Us6657595b1 sensordriven adaptive counterpoise antenna. Under this item the contractor shall repair and restore the existing counterpoise system where the proposed project interferes with the existing counterpoise system andor when damaged during excavation operations. Changes made to reflect the nws headquarters reorganization effective april 1, 2015. Metal frame of the building or structure where the following methods are used to make an earth connection. The external grounding earthing electrode system may consist of, but is not limited to, the following components, shown in figure 44. For some antennas, the antenna is simply not complete without a radial system, or at least a counterpoise. Some have been able to erect better wires in the air because the small size of the fcp allowed better placement of the antenna.
New awg 20 ground leads from the wires connect to a new low resistance electrode. The radiating portion of your antenna needs to see a mirror image of itself before it will send out your ssb signal. If each operating band has its own separate counterpoise, then each respective counterpoise will function as the operating band is changed, allowing multiband operation and preventing severe rfi in the shack caution. To connect the metallic conductive parts of an electric appliance or installations to. Antenna used in lodgemuirhead wireless system around 1900, the first counterpoise. Substation grounding design challenges and lessons learned. Portable vertical antenna counterpoise kit cha counterpoise kit. Grounding counterpoise good grounding or counterpoise techniques are absolutely necessary for maximum single sideband range. This value is almost always resistive, though complex counterpoise grounding systems may. Pdf effective length of counterpoise wire under lightning. Pipe earthing and counterpoise earthing cr4 discussion thread. In order for a lightning protection system to safely and quickly dissipate direct and indirect lightning currents and voltages, the integrity of all elements of the lightning protection system must be verified. Easypower is partnering with the industryleading grounding and emi analysis expert company, sint ingegneria, which offers a software package to analyze and design grounding, lightning and electromagnetic interference problems by focusing on its powerful and yet affordable grounding analysis software packages, xgslab. Below ground earthing conductors, counterpoise, and grounding grids.
An allcopper grounding system installed in 2002 put an end to the damage, improving public safety and eliminating high repair costs. Counterpoise and rf grounding a mobile antenna nashua area. Grounding of a 230 kv transmission line over a limestone ridge. Lightning protection design, earthing system design lightning protection for buildings design duration.
Pdf recommendations for grounding systems in lightning. The counterpoise impedance equations are shown in scott. Counterpoises, when properly implemented, can be very effective. An adaptive antenna system having a counterpoise conductor contained within a housing of a communication device and located distally from such surfaces of the housing that can be held by or placed in proximity to a user or external objects which detune the counterpoise. For duct not along a shoulder or for duct bank, counterpoise to be 1015.
Electrical earthing, grounding, methods of earthing, types of earthing, components of earthing and its specifications in respect to electrical earthing for electrical installations. The author, stan honey, is a renowned sailor, navigator and electrical engineer. Army 51 and air force 4 regulations are identical to the dod 121. However, at the manhole structure, both the counterpoise and the airports bare cu conductor are bonded in the same way. It is used with radio transmitters or receivers when a normal earth ground cannot be used because of high soil resistance or when an antenna is mounted above ground level, for example, on a building. Counterpoise lightning protection system provide a continuous counterpoise of number 4 minimum awg bare, stranded copper wire over the entire length of all. Counterpoise system and grounding for airfield mike holts. Equipment grounding may also include the use of agl transformers having means for grounding one side of the secondary winding.
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