1794
THE NEW ZEALAND GAZETTE.
[No. 64

18. 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 but is within 7 ft. from the building shall be completely enclosed in stout indiarubber tubing.

19. 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°, and the spans shall be as short as possible.

20. 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 of the metallic substance coming into contact with the line, by breakage or otherwise.

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

22. Efficient guard-wires shall be erected in a manner to meet with the approval of the Electric Telegraph Commissioner at all such crossings and places where 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 electric-lighting wire intersects a telegraph or telephone wire previously existing.

23. 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.

24. 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 intend within a reasonable time again to take it into use.

25. All metal pipes or casings containing any electric line shall be efficiently connected with earth, and shall be so jointed as to make good electrical connection throughout their whole length.

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

27. 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.

28. All electric lines and apparatus placed on a consumer’s premises shall be highly insulated, 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 protected as to prevent the possibility of electrical discharge to any adjacent metallic substance.

29. Where the demand does not exceed 2½ kilowatts the service mains for all installations, whether of lighting (excepting arc-lighting) or power, shall consist of two conductors taken from one outer and the neutral wire.

30. Where the demand for lighting exceeds 2½ kilowatts the main may consist of three conductors taken from the two outers and the middle wire, and where three conductors are used for the service mains the premises shall be wired with two circuits kept separate from each other, and the load shall be divided as nearly as possible equally between them.

31. The Corporation shall fix, where their service mains terminate on any premises, single-pole well-protected fuses on each conductor of at least 1½ in. clear break. They shall also fix double-pole main switches of ample carrying-capacity, well insulated, with quick break of sufficient clearance to prevent arcing. When the premises are wired for a consumption of 5 kilowatts or over, either from one outer and the neutral wire or from both outer wires and the neutral wire, the break switches should be fitted with magnetic blow-out or other equivalent device for extinguishing the arc, and a distance of at least 4 in. shall separate their poles. Where the supply is taken from the two outers and the middle wire two double-pole break switches shall be used, the neutral wire being joined to one terminal of each, and they shall be placed not less than 6 in. apart. They may be arranged to operate simultaneously.

32. All wiring shall be done from distributing-boards, which shall be of incombustible material. Suitable fuses on each pole fitted to engage in spring clips shall be placed on these boards, so that it shall be possible to disconnect any or all circuits from the supply.

33. The covers of fuses, switches, and plugs shall be of porcelain or other incombustible non-conducting material, or of rigid metal lined with vitreous enamel or suchlike substance. All metal parts liable to be touched must be effectively insulated from the electrical circuit. Where switchboards are accessible only to some responsible person, separate insulated covers for the parts mounted thereon will not be required.

34. There must be a porcelain bridge or other efficient insulation between the terminals of lamp-holders, and where lamp-holders are liable to be handled by persons making good earth contact they must be provided with non-conducting covers. Not more than ten sixteen-candle-power lamps, or their equivalent, shall be controlled by each switch.

35. The insulation-resistance of conductors used for the wiring for lighting or heating purposes shall not be less than 600 megohms per mile after one minute’s electrification and twenty-four hours’ immersion in water immediately preceding the test. Concentric conductors may be used, and their insulation-resistance shall not be less than that required for separate conductors.

36. 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.

37. 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.

38. Arc lamps used in any street for private lighting shall be so fixed as not to be in any part at a less height than 8 ft. from the ground, and shall be so screened as to prevent risk of contact with persons.

39. Arc lamps must be insulated from earth, and fixed so that they cannot swing into contact with any substance, metallic or otherwise, that might connect them to earth. They may be supplied with current from the two outer wires of the supply system. The insulation resistance of the conductors supplying them with current when such conductors are not aerially suspended shall not be less when the current is taken from the outer wires than 2,500 megohms per mile after one minute’s electrification and twenty-four hours’ immersion in water immediately preceding the test. These insulated conductors, when taken from the outer wires, shall be run in strong metal casing, which shall be electrically continuous and effectively connected with earth. Resistances for the regulation of arc lamps shall be mounted on incombustible bases, shall be so placed that they cannot by conduction or radiation set fire to any contiguous materials, and shall be of ample size to safely carry the maximum current that will normally flow through them. Each arc-lamp circuit shall be provided with a switch and fuse on each pole.

40. Motors shall be either of the enclosed type or enclosed in strong metal cases, and shall be efficiently ventilated. Motors up to 3½-horse power may be supplied with current at 220 volts, due regard being had to “balancing” and avoidance of disturbance to lighting.

41. The magnet, frame, and shaft of all motors shall be connected to an efficient earth by a copper conductor, capable of carrying without overheating ten times the fusing-current of the main fuse. All metal casings of switches, resistances, fuses, cables, and wires shall be efficiently earthed in a similar manner.

42. An approved starting switch and resistance shall be used on all motors connected directly with the mains, so arranged that the current can only be gradually increased.

43. Every motor must be controlled by an efficient double-pole quick-break switch suitable to prevent arcing, and conveniently placed so that the person in charge of the motor can cut off wholly the supply from the motor, and all devices in connection therewith. This switch should interlock with the starting-switch so that while it can be operated to cut off the supply in any position of the starting-switch, it can only be closed when the starting-switch has been placed so as to put all the resistance in circuit.

44. A minimum-current cut-out must be provided to disconnect the motor should the supply become interrupted. This arrangement may be in the starting-switch if found convenient.

45. Efficient single-pole fuses or other automatic cut-out must be provided to efficiently protect the conductors on each pole from excess of current, and where these are used to guard conductors taken off the two outer wires of the supply system, provision shall be made to extinguish the arc.

46. Precaution shall be taken in choosing positions for and in setting up motors and the necessary devices in connection therewith so that there shall be no danger of fire being caused by their normal or abnormal action, or of shock being obtained in the ordinary handling thereof.

47. Brush rockers must be arranged so that they cannot bring either conductor into contact with the framework of the motor.

48. Terminals of motors must be guarded so that they cannot be accidentally touched or short-circuited.