3344
THE NEW ZEALAND GAZETTE.
[No. 89

buildings or shelters, which shall be kept locked and be accessible only to authorized persons.

15. The metal frames of the transformers and, when star connection is employed, the centre point also of the winding shall be effectively connected to earth. All transformers that are not under shelter shall be fitted with watertight cases, and where underground chambers are used for sheltering them precaution must be taken to avoid the chambers becoming flooded, and to provide by ventilation or otherwise against the accumulation of gas or high temperature. The earth-wires shall be of stranded copper of suitable cross-section to prevent danger, and those used for earthing transformers placed on poles or buildings shall be highly insulated and carefully protected throughout from all liability of damage or of being interfered with. The earth-wires shall be run as straight as possible, and be properly electrically connected to an efficient earth which shall be provided at the site of the transformer. The earth-wires shall be maintained intact and in good contact with the earth-plate.

Distribution.

16. Overhead or underground distribution, direct current included, may be adopted for all pressure not in excess of 3,300 volts. If underground distribution should be required to be made in excess of 3,300 volts, the permission of the Board of Control shall be specially obtained.

17. Throughout the area of supply, where it may be at any time available, direct current at 500 to 550 volts may be used for tramway purposes, arc-lighting, elevators, and hoists.

18. The “converter station” and any other station for a like purpose that may in the future be required to be established in any part of the area of supply shall be laid out, maintained, controlled, and properly equipped with mechanical and electrical appliances generally that shall at all times be sufficient and suitable for securing to consumers the full advantages of the electrical supply.

19. The high-pressure distribution may be by the one-, two-, three-, or four-wire system, as may be necessary. The medium- and low-pressure three-phase distribution shall be by the four-wire system throughout, one outer and the neutral being used for a single-phase service.

20. For the medium- and low-pressure three-phase system the pressure shall be 400 volts between the outers, and 230 volts between each outer and the neutral wire; and for direct-current constant potential circuits the pressure shall be 500 to 550 volts. Direct-current constant-current street-lighting circuits may be supplied at any pressure up to 3,000 volts.

21. Within the City of Dunedin and all boroughs all high-pressure wires placed overhead shall be insulated throughout their entire length with not less than 600-megohms grade of vulcanized rubber, except over certain portions for which special provision has been made. Outside the City of Dunedin and all boroughs the high-pressure wires may be bare, but in places where population may be increasing, if the Board of Control considers that bare wire carrying high pressure should not be erected, or that if erected its use should not be continued, the wire shall be insulated throughout with 600-megohms grade of vulcanized rubber.

22. Within the City of Dunedin and the Boroughs of St. Kilda, Roslyn, Maori Hill, Mornington, North-east Valley, West Harbour, and Port Chalmers, and the Road Districts of Peninsula, Tomahawk, and Portobello the outers of the three-phase medium- and low-pressure wires, where they run on Corporation poles, shall be insulated with not less than triple weatherproof insulation; and, where they are attached to or run on the poles of the Post and Telegraph Department, with not less than 300-megohms grade of vulcanized rubber. In all other places where they run on Corporation poles the three-phase medium- and low-pressure wires may be bare, but if they are placed on the Telegraph Department’s poles all except the neutral wire, which may be bare, shall be insulated with 300-megohms grade of vulcanized rubber.

23. The high-pressure wires shall be insulated with not less than 600-megohms grade of vulcanized rubber wherever they are run on the same poles as the medium- or low-pressure wires.

24. The neutral wire of all overhead single or three-phase high-, medium-, and low-pressure circuits may be bare.

25. High-pressure circuits of one, two, three, or four wires may cross from the Corporation poles to the Telegraph Department’s poles to enable them to be taken through the Department’s line for supply on that side of the street or road. The series street-lighting wires may be run along on the Department’s poles in cases where special written permission has been given by the Minister of Telegraphs after application in writing for such permission has been made. No other high-pressure wires shall be run on the Department’s poles.

26. Medium- and low-pressure circuits of two, three, or four wires may cross over to the telegraph-poles so that they may be carried through or run along these poles for supply on that side of the street or road.

27. Not more than two three-phase electric light and power circuits shall be attached to any telegraph-pole, and not more than two medium- or low-pressure three-phase circuits shall be run on such poles. If a direct-current circuit is run on telegraph-poles only, one three-phase circuit may be run on the same poles.

28. The neutral of the high-pressure circuits that are attached to telegraph-poles so as to pass from one side of a street or road to another shall be insulated with at least 600-megohms grade of vulcanized rubber where it passes on the pole.

29. The high- and the medium- or low-pressure wires shall be arranged as far as may be practicable lower down on the poles than the telegraph-wires, in a way that shall be approved by the Telegraph Engineer, and so that there shall be no danger of shock to men working on any part of the pole.

30. The medium- and low-pressure wires when run on the Telegraph Department’s poles shall be run along on one side of them, the neutral being preferably nearest to the pole and at least 1 ft. distant from it.

31. On all telegraph-poles that have high-pressure wires attached to them there shall be placed and maintained a conspicuous “Danger” notice.

32. The permission to use telegraph-poles for carrying electric light and power wires shall not be understood as giving the Corporation any right to the use of such poles, and if the presence of the electric light and power wires on the Telegraph Department’s poles is found at any time to be prejudicial to the interests of that Department they shall be removed, on reasonable notice being given to the Corporation by the Minister of Telegraphs.

33. Throughout the whole area of supply the permission to place electric light and power wires on the Telegraph Department’s poles shall be restricted as far as possible, and in no case shall such wires be attached to the Telegraph Department’s poles without the approval of the Minister of Telegraphs being first obtained.

34. All overhead wires shall be of hard-drawn copper, and when rubber-insulated they shall be tinned.

35. Where the telegraph-wires are not metallic circuit the electric light and power wires shall not be run along or be attached to the Telegraph Department’s poles, unless such running along or attachment can be done by such methods as will not give rise to inductive disturbances in the Department’s circuits.

36. Overhead distribution-lines shall occupy as far as possible only one side of any street or road, and shall be placed on the opposite side of the street or road where any telegraph-lines exist at the time of their erection, unless special permission to do otherwise be obtained from the Minister of Telegraphs. Where overhead distribution-lines cross over railways the minimum height above the ground of such crossings shall be arranged with the Railway Department, but in any case shall not be less than 18 ft., and where trolley-wires are crossed over the electric-light wires shall cross at a height above out of reach of the trolley-pole, and shall, if required, be securely suspended by rawhide hangers or other suitable means from galvanized-steel bearer-wires, which shall be firmly attached to strong porcelain insulators. Wherever it may be necessary to cross telegraph fire-alarm or other wires, the electric light and power wires shall cross above as far as may be practicable, and shall be at least 3 ft. distant. Where it is impracticable to cross above, the electric light and power wires may be taken under or through, but when taken through the crossing shall be made at a pole.

37. Where the electric light and power wires intersect telegraph or other wires, the latter shall be suitably insulated if deemed necessary, and when the crossing is above and near a pole, the spans on each side of the pole may require to be insulated. This insulation shall be effected at the expense of the Corporation in cases where the telegraph-lines existed previously to the erection of the light and power wires.

38. Where electric light or power wires intersect telegraph or other wires the high-pressure wires shall be insulated with not less than 600-megohms grade of vulcanized rubber, and the medium- or low-pressure with not less than 300-megohms grade rubber. The neutral wires may be bare except in the case of high-pressure neutrals attached to telegraph-poles.

39. The direct-current supply-wires at 500 to 550 volts run overhead on Corporation poles shall be covered throughout with not less than triple weatherproof insulation. The return-wires may be bare. On all other poles the