Sept. 29.] THE NEW ZEALAND GAZETTE. 2311

the trolly-wires, and the spans should be as short as possible. Wherever it may be necessary to cross over telegraph, telephone, or fire-alarm wires, the electric-light wires shall cross at a safe height above in all cases. Where electric-light lines may be run in any street in which there are no telegraph or telephone wires, they shall be so erected that, when it may be necessary to extend telegraph or telephone lines into any such street, wherever crossings of the wires of the two lines shall occur the electric-light wires shall be always above.

11. Where the erection of the electric lines or wires necessitates the alteration of existing telegraph or telephone lines or wires, the expense of such alteration shall be borne by the Corporation.

12. The maximum working-current in any conductor shall not be sufficient to raise the temperature of the conductor or any part thereof to such an extent as to materially alter the physical condition or specific resistance of the insulating covering, if any, or in any case to raise such temperature to a greater extent than 30° Fahr. The cross-sectional area and conductivity at joints must be sufficient to avoid local heating, and the joints must be carefully made, resin being used as a flux, and must be protected against corrosion. The sectional area of all conductors on the consumer’s premises from the main switchboard or from any distribution-block must be maintained throughout the circuit, and joints should be made only when branching off a circuit, and should be at least 8 in. distant from a joint in any other conductor.

13. The sectional area of the conductor in any electric line laid or erected in any street shall not be less than the area of a circular wire 100 mils in diameter, and where the conductor is formed of a strand of wires each separate wire shall be at least as large as No. 20 standard wire gauge.

14. 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.

15. 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.

16. No high-tension distributing-circuit shall be brought into use unless the insulation of every part thereof has withstood the continuous application during one hour of pressure exceeding twice the maximum pressure to which it is intended to be subjected in use. All the low-tension circuits shall also be tested before being brought into use with at least 220 volts. The Corporation shall duly record the result of such tests.

17. The insulation of every complete high- and low-tension distribution-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; and suitable means shall be provided for the immediate indication of leakage on all high-tension circuits, and on the low-tension circuits that are run underground from the converter-station. Every such circuit shall be tested for insulation at least once in every week, and the Corporation shall duly record the results of the testings.

Provided that where the Electric Telegraph Commissioner has approved of any part of any electric circuit being connected with earth, the provisions of this section shall not apply to that circuit so long as the connection with earth exists. This exemption from test shall not apply to any high- or low-tension circuit run underground. If any such underground circuit has any part of its windings connected to earth, suitable provision shall be made, if necessary, to break the earth-connection for insulation-testing purposes.

18. Where any portion of any electric line or any support for an electric line is exposed in such a position as to be liable to injury from lightning, it shall be efficiently protected against such injury.

19. Every aerial line carrying low-tension wires only 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 wires make a horizontal angle at the point of support.

20. Every support for an aerial line shall be of a durable material, and shall be 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 at least 6, and for all other parts of the structure at least 12, taking the maximum possible wind-pressure at 50 lb. per square foot.

Every support, if of metal, shall be efficiently connected with earth.

21. All aerial lines shall be attached to double-shed porcelain 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 not be attached to the insulators by uninsulated metal binders.

22. 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 building or erection other than a support for the line, except where led to transformers on suitable buildings, or brought into a building for the purpose of supply.

23. 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. They shall be led into the consumer’s premises through suitable inlet-tubes.

24. Where an aerial wire 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°, and the spans shall be as short as possible.

25. 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, or if the metallic substance coming into contact with the line, by breakage or otherwise.

26. Where telegraph or telephone wires are crossed over by the high-pressure electric-light wires, the former shall be insulated throughout the whole length of the span intersected, and when the crossing is near a telegraph or telephone pole the spans on each side of the pole shall be insulated if deemed necessary, in all cases at the expense of the Corporation.

27. Efficient guard-wires shall be erected in a manner to meet with the approval of the Electric Telegraph Commissioner at all crossings and places where aerial electric-lighting wires intersect telegraph or telephone wires as may be required by the Commissioner to be so protected. The Corporation shall bear the expense of such guard-wires in all cases where an aerial electric-lighting wire intersects a telegraph or telephone wire previously existing.

28. Every aerial line, including its supports 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.

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

30. Where the electric lines are run in cables laid underground, the cables may be placed in conduits, metal pipes, or solid in wood troughing, and all such receptacles shall be constructed of durable materials, which shall be of sufficient strength and be buried deeply enough to resist damage from heavy traffic. Reasonable means shall be taken and periodical inspection made by the Corporation to prevent accumulations of gas in those receptacles. Underground feeder-cables, lead-covered and well armoured, may be laid direct in the ground. The conductors of all underground cables shall be well insulated from earth, and from each other in the case of multiple conductor cables.

Where any underground electric line crosses or is in proximity to any metallic substance, special precautions shall be taken by the Corporation against the possibility of any electrical discharge to the metallic substance from the line, or from any metal conduit, pipe, or covering enclosing the line.

The lead sheathing, if any, of all electric cables laid underground, and all metal conduits, pipes, or coverings containing any electric line, shall be efficiently connected with earth, and shall be so joined and connected up as to make good electrical connection throughout their whole length.

Where isolated lengths of metal conduit, pipe, or covering are used for the protection of any electric line at road-crossings or similar positions, special precautions shall be taken to prevent the possibility of any electrical charging thereof.

31. The Corporation shall be responsible for all electric lines, fittings, and apparatus belonging to it, or under its control, which may be upon a consumer’s premises, being maintained in a safe condition and in all respects fit for supplying energy.

In delivering the energy to a consumer’s terminals the Corporation shall exercise all due precautions so as to avoid risk of causing fire on the premises.

All electric lines and apparatus placed on a consumer’s premises shall be highly insulated, and be suitable for the voltage at which supply is being given, excepting such parts as are required to be connected with earth, and thoroughly protected against injury to the insulation or access of moisture, and any metal forming part of the electric circuit shall not, unless efficiently connected with earth, be exposed so that it can be touched. All electric lines shall be so fixed and