✨ Electrical Supply Regulations
2442
THE NEW ZEALAND GAZETTE.
[No. 63
As the conditions of supply are such that the pressure at any pair of consumer's terminals does not exceed 250 volts, the supply shall be deemed a low-pressure supply.
“Telegraph” includes telephone.
Any metallic body to be “efficiently connected with earth” shall be connected with the general mass of the earth in such manner as will insure at all times an immediate and safe discharge of electrical energy.
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The supply of electrical energy shall be given by the continuous-current two- or three-wire system.
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Continuous current shall be generated at about 110 volts between each outer and the neutral conductor, and at about 220 volts between the outers of the system, the declared pressure at the consumers’ terminals being 110 and 220 volts respectively.
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The neutral wire of the three-wire system shall be earthed only at the power-station. It shall be so erected and specially supervised as to reduce to a minimum its liability to break, so as to avoid the burning-out of consumers' lamps. At other places its insulation shall be maintained the same as that of the outers. A switch shall be provided to cut off the earth from the neutral wire for testing purposes.
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The main switchboard shall be made of and be mounted on material that is not inflammable.
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All overhead conductors shall be of hard drawn copper, and where they cross over or under open telegraph or any other aerial wires they shall be insulated throughout the entire length of every crossing-span with not less than 300-megohms-per-mile grade of vulcanized rubber, except that where it may be impracticable or undesirable to so insulate the electric-light wires over spans at such crossing-places the insulation of the electric-light wires may be triple weatherproof, provided that all other aerial wires referred to are insulated at those crossing-spans with not less than 300-megohms-per-mile grade of vulcanized rubber, or are otherwise satisfactorily insulated. In cases where telegraph or other aerial wires already exist and are required to be insulated, their insulation shall be effected at the Corporation’s expense, and shall be to the satisfaction of the Minister of Telegraphs.
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Except where otherwise provided, the overhead conductors may be of bare hard drawn copper wire. If at any time it be found detrimental to the public safety to have these wires bare, they shall be insulated when deemed necessary. No electric-light wire shall come within 3 ft. of any other class of aerial wires or of cables, except where it may be permitted to pass the electric-light wires through these other wires or cables at a pole.
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Where lead-covered telephone cables are crossed above by the electric-light wires, the latter wires shall be insulated with not less than 300-megohms-per-mile grade of vulcanized rubber throughout the crossing-span, and over every such span they shall be suitably suspended from effectively earthed steel bearer-wires if the Minister of Telegraphs shall so require.
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Where lead-covered telephone cables may be crossed under by the electric-light wires, if the height and other circumstances permit—and of this the Minister of Telegraphs shall be the judge—the latter wires shall be insulated as in clause 7, and suspended if deemed necessary.
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In places where it may be required to cross with the electric-light wires through any other aerial wires or through cables because of the impracticability of crossing above or below—and crossing above or below shall be done if possible—all such through crossings, if permitted, shall be effected at a pole. In every case of a through crossing, no matter whose property the lines crossed through may be, the method of carrying the electric-light wires across the pole, protecting them thereon, protecting other wires from coming into contact with them, and protecting persons working on the poles from danger of shock, shall be to the satisfaction of the Minister of Telegraphs. The electric-light wires shall be insulated with not less than 300-megohms-per-mile grade of vulcanized rubber where they pass through on the poles and over the whole length of the span on each side of the pole crossed through. Where the insulated wires cross through on the pole they shall be encased in some hard protecting substance for the entire length of the arms on such pole. If metal pipe be used to encase the wires it shall be effectively earthed.
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In running these lines through streets where no telegraph lines exist, the Corporation shall keep to one side of the street, and in running service wires to the opposite side of the street to that on which their line of poles is placed the Corporation shall arrange to supply so as to interfere as little as possible with the route on that side of the street.
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Except by permission of the Minister of Telegraphs, all overhead electric-light pole lines shall be placed on the opposite side of the streets to that on which any telegraph-pole lines exist; and where the erection of the electric-light wires necessitates the alteration of telegraph wires that may exist when the electric-light wires are being run, and such alteration is practicable, the expense of the alteration shall be borne by the Corporation.
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Where the electric-light wires are on one side of a street and the telegraph wires are on the other, and service is required to be given from each to the other side of the street, each party shall give the other reasonable facilities as far as possible to effect supply.
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Where it cannot be arranged otherwise, and there is room on the telegraph poles, and other circumstances do not render it unsafe or impracticable, the electric-light wires may be run along on the telegraph poles, subject to their insulation being not less than 300-megohms-per-mile grade of vulcanized rubber and to any special conditions that it may be found necessary to impose at the time that the placing of such electric-light wires on the telegraph-poles is being considered.
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When the electric-light pole lines are being laid out provision should be made by increased length of pole to provide clearance to facilitate crossing with telegraph service wires to the side of the street occupied by the Corporation’s line.
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Telegraph wires shall not be run along or placed on the Corporation’s poles, nor shall the Corporation’s wires be run along or placed on telegraph poles, without a special understanding of requirements and precautions to be observed being arrived at between a responsible officer of the Corporation and of the Minister of Telegraphs in respect of each case. Rental at a rate to be agreed upon may be charged for the use of poles, but nothing in this license shall be construed to give any party a right to the use of poles other than its own.
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Every main shall be tested for insulation after having been placed in position and before it is used for the purposes of supply, the testing pressure being at least 220 volts, and the Corporation shall duly record the results of the tests of each main or section of a main.
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The insulation of every complete aerial and underground circuit used for the supply of energy, including all machinery, apparatus, and devices forming part of or in connection with such circuit, shall be so maintained that the leakage current shall not under any conditions exceed one-thousandth part of the maximum supply current. Every leakage shall be remedied without delay. Every such circuit shall be tested for insulation at least once in every week, and the Corporation shall duly record the results of the tests.
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The sectional area of the conductor in any electric line laid or erected in any street shall not be less than that of a strand of seven wires, each of which is of No. 20 standard wire gauge, and the sectional area of every wire in a strand forming any such conductor shall not be less than that gauge.
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All material used for insulating electric lines or apparatus shall be of the best quality, and thoroughly durable and efficient, having regard to the conditions of its use. Suitable provision shall be made for the protection of the insulating material against injury or removal.
If the protection so provided be wholly or partly metallic, it shall be efficiently connected with earth.
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All metal pipes or coverings containing any electric wire shall be efficiently connected with earth, and shall be so jointed as to make good electrical connection throughout their whole length.
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Arc lamps used in any street for public lighting shall be so fixed as not to be in any part at a less height than 10 ft. from the ground.
All arc lamps shall be so guarded as to prevent pieces of ignited carbon or broken glass falling from them, and shall not be used in situations where there is any danger of the presence of explosive dust or gas.
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The variation of pressure at any consumer’s terminals shall not, under any conditions of the supply which the consumer is entitled to receive, exceed 4 per cent. from the normal pressure at which he is being supplied.
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Every aerial line shall be attached to supports at intervals not exceeding 200 ft. where the direction of the line is straight, or 150 ft. where the direction is curved or where the line makes a horizontal angle at the point of support.
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Every support for an aerial line shall be of a durable material, and properly stayed against forces due to wind-pressure, change of direction of the line, or unequal lengths of span. The factor of safety shall be for all aerial lines and suspending wires, and for all other parts of the structure, at least 6, taking the maximum possible wind-pressure at 20 lb. per square foot.
Earth-wires, where led down poles, shall be protected by casing for a distance of 8 ft. from the ground.
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All aerial wires shall be attached to suitable insulators carried on cross-arms of suitable material and cross-section, and they shall be so attached to the insulators or guarded that they cannot fall away from the support. Conductors covered with insulating material shall be so attached that their insulation will not be impaired where they are secured to the insulator.
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Any aerial wire shall not in any part thereof be at a less height from the ground than 18 ft., or within 5 ft. measured horizontally or 7 ft. measured vertically from
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✨ LLM interpretation of page content
🏗️ Regulations for the Supply of Electrical Energy
🏗️ Infrastructure & Public WorksElectrical supply, low-pressure, continuous current, three-wire system, conductors, insulation, safety, Minister of Telegraphs, public safety
- Minister of Telegraphs
NZ Gazette 1911, No 63