1398

THE NEW ZEALAND GAZETTE.

[No. 38

earth in such manner as will insure at all times an immediate and safe discharge of electrical energy.

1. The supply of electrical energy shall be given to private consumers by means of alternating current on the two- or three-wire system at a pressure of 220 volts effective between each of the outer wires and the neutral and 440 volts between the two outer wires. The declared voltage at the consumers’ terminals shall be 220 or 440 volts respectively.

2. The neutral wire shall be efficiently insulated throughout its length, but shall be earthed at the power-station, and only at the power-station. The earth connection shall be provided with a switch for cutting off the earth connection for testing, and with a recording ammeter reading to a maximum of 5 amperes.

3. The street lamps shall be supplied by means of a constant-current series system. The maximum voltage between the terminals of this system shall not exceed 1,000 volts effective pressure. All overhead wires included in the series lighting system shall consist of 7/18 S.W.G. stranded cable, insulated by means of rubber insulation of at least 600-megohm grade. All lamp-sockets in the series lighting system shall be provided with an automatic device which will immediately short-circuit the lamp if the voltage across its terminals should rise above 500 volts.

4. The main switchboard shall be made of and be mounted on material that is not inflammable.

5. Where overhead conductors 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 600-megohm grade of vulcanized rubber.

6. Except where otherwise provided, the overhead conductors may be of bare hard-drawn copper wire. If at any time it is found detrimental to the public safety to have these wires bare, the said Council shall cause the same to be insulated when directed so to do by the Minister. No electric-light wire shall come within 3 ft. of any other class of aerial wires or of cables, except where permission is given to pass the electric-light wires through these other wires or cables at a pole.

7. Where lead-covered telephone cables are crossed above or beneath by the electric-light wires, the latter wires shall be insulated with not less than 600-megohm 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 shall so require.

8. In places where it may be required to cross with the electric-light wires through any other aerial wires or through cables, 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. The electric-light wires shall be insulated with not less than 600-megohm 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 a protecting tube for the entire length of the arms on such pole. If metal pipe be used to encase the wires it shall be effectively earthed.

9. In running these lines through streets where no telegraph lines exist, the Council 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 said Council shall arrange to supply so as to interfere as little as possible with the route for a future telegraph line on that side of the street.

10. Except by permission of the Minister, 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 Council.

11. 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 either to the other side of the street, each party shall give the other reasonable facilities as far as possible to effect such service.

12. 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 440 volts, and the said Council shall duly record the results of the tests of each main or section of a main.

13. 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 said Council shall duly record the results of the tests.

14. The sectional area of the conductor in any electric line laid or erected in any street shall be not less than 7/20 standard wire gauge.

15. 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.

16. 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.

17. The variation of pressure at any consumer’s terminals shall not exceed 4 per cent. above or below the normal pressure at which he is being supplied.

18. 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.

19. 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 for all aerial lines and suspending wires, and for all other parts of the structure, shall be at least 5, taking the maximum possible wind-pressure at 30 lb. per square foot.

Earth-wires, where led down poles, shall be protected by casing for a distance of 8 ft. from the ground.

20. 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.

21. 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 any part of any building or erection other than a support for the line, except where brought into a building for the purpose of supply.

22. Service lines from aerial lines shall be led as directly as possible to insulators firmly attached to some portion of the consumer’s premises which is not accessible to any person without the use of a ladder or other special appliance. Every portion of any service line which is outside a building, and is within 7 ft. from any part of the building, shall be rubber-insulated.

23. Where an aerial line crosses a street, the angle between the line and the direction of the street at the place of crossing shall not be less than 60 degrees, and the spans shall be as short as possible. The minimum height of the line shall be 20 ft. above the street level.

24. Where an aerial line crosses or is in proximity to any metallic substance, precautions shall be taken against the possibility of the line coming into contact with the metallic substance by breakage or otherwise.

25. If the Minister of Telegraphs so requires, efficient guard-wires shall be erected in a manner to meet with the approval of the said Minister at all crossings and places where the electric-light wires intersect telegraph wires. The Council shall bear the expense of such guard-wires in all cases where an electric-light wire intersects a telegraph wire previously existing.

26. Every aerial line, including its supports, its conductors, and their insulating covering, and all the structural parts and electrical appliances and devices belonging to or connected with the line, shall be duly and efficiently supervised and maintained as regards both electrical and mechanical conditions.

27. An aerial line shall not be permitted to remain erected after it has ceased to be used for the supply of energy, unless the said Council intends within a reasonable time again to take it into use.

The electric-light wires may be placed wholly underground or partly underground and partly overhead.

28. All conduits, pipes, casings, and street boxes used as receptacles for electric lines shall be constructed of durable material, and shall be of ample strength to prevent damage from heavy traffic, and reasonable means shall be taken to prevent the accumulation of gas in such receptacles.