Sept. 15.] THE NEW ZEALAND GAZETTE. 2217

mission-wire, should it sag unduly or become broken, before
the broken end can reach the ground.

11. The extra-high-tension transmission-lines shall extend
    only to the outskirts of each of the four towns to be supplied,
    except as hereinafter provided for at Hawera. At Okaiawa,
    Normanby, and Manaiā the oil-filled three-phase trans-
    formers for transforming current for distribution may be
    placed on strong wooden poles at such a height as to be
    accessible only by means of a ladder or other similar special
    appliance. If not placed on poles, transformers shall be
    contained in suitable structures, preferably fireproof, acces-
    sible only to the company.

12. At Hawera the oil-filled three-phase transformers shall
    be placed in a sub-station preferably fireproof, and accessible
    only to the company.

13. At points other than Okaiawa and Normanby along
    either transmission-line where it may be desired to supply
    energy en route for lighting or power purposes, single-phase
    transformers may be used to tap the transmission-line, and
    these transformers shall be as far as possible balanced
    across the three phases, and shall transform from 5,000
    to 220 volts. Three phase transformers may be used
    at points along and near to the transmission-routes
    where the demand for power is such as to render it undesir-
    able to supply from single-phase transformers, and where
    three-phase transformers are so used, motors may be supplied
    from the three outers at 380 volts, and lamps from any one
    outer and an earthed neutral at 220 volts.

14. Three-phase transformers shall be oil-filled unless
    they are provided with ventilated iron cases. The windings
    of the primary may be mesh and of the secondary shall be
    star connected. All transformers shall have easily remov-
    able fuses for the primary circuit, may have secondary
    fuses, and the fuse-chambers shall be entirely separate from
    the transformers. All transformers affixed to poles shall be
    fitted with watertight cast-iron cases. Single-phase trans-
    formers transforming to 220 volts shall be fitted with Car-
    dew’s or other approved earthing device, which shall be set
    for not more than 450 volts. A test shall be made of each
    transformer every six months to see that each coil is highly
    insulated from the other and from the iron case, and that
    the earthing-devices will operate at the voltages for which
    they are set. A record shall be kept by the company of the
    result of all such tests.

15. All wooden poles used shall be of totara or other
    approved timber, and where transformers are not under shelter
    in a special structure they shall be securely attached to
    wooden poles, which shall be specially strong.

16. Every transformer and the power-station shall be pro-
    tected against lightning by Siemens’s horn or other approved
    lightning-guards, with choking coils. A guard shall be placed
    on each transmission-wire at its entrance to the power-station,
    and on each aerial wire leading into transformers. One side of
    each lightning-guard shall be connected direct to an efficient
    earth, which shall be provided, in the case of transformers,
    at the site of the transformer being protected. No wire
    smaller than the equivalent of a No. 6 standard wire
    gauge copper wire shall be used for making the earth-
    connection. The wire shall be insulated, and shall be pro-
    tected by casing from all liability of damage or of being
    interfered with. An examination and test shall be made
    every three months, and oftener if required, of all earths, to
    secure that the earth-wire is intact, its insulation unim-
    paired, that it is in intimate contact with the earth-plate,
    and that the earth is effective. The iron case of each
    transformer shall be electrically connected direct with the
    earth at its site, and the earthed No. 8 copper wire shall be
    efficiently electrically connected to each one of these direct
    earths.

17. Where wires on the transmission-line cross other
    wires, either telephone or telegraph, they shall cross at a
    safe height above, and as nearly at a right angle as pos-
    sible. At all such crossings no span shall exceed 1 chain
    in length, where practicable, and all wires on the trans-
    mission-line shall be insulated with 2,500 megohms per mile
    grade of vulcanised rubber insulation, taped and braided,
    and be efficiently suspended from steel bearer-wires by strong
    raw-hide hangers, spaced not more than 15 in. apart, or
    by small porcelain insulators firmly fastened to the bearer
    wires, which shall be securely attached to triple-shed porce-
    lain insulators. The telephone and telegraph wires at such
    crossings shall also be insulated, and at the company’s ex-
    pense.

18. The transmission-lines shall be patrolled at least once
    a week, and insulation shall be maintained so that the mini-
    um of all three wires tested as one wire shall not be less
    than 1 of a megohm when tested with a voltage equal to
    that used in transmitting energy. Daily tests shall be made
    and recorded.

19. From the site on Section 25 of the transformer sub-
    station at Hawera to Block 183, a distance of, approximately,
    10 chains, the high-power transmission-wires shall be well
    insulated with 2,500 megohms per mile grade of vulcanised

rubber insulation throughout their entire length, shall be
suspended from suitable bearer-wires, and be supported by
strong wooden poles placed at distances apart not exceeding
1½ chains.

20. Distribution to consumers in the four centres of
    Okaiawa, Manaiā, Normanby, and Hawera shall be on the
    three-phase four-wire system—the fourth or neutral wire
    being connected to the centre of the secondary star winding
    of the transformers, and that centre point of the transformer-
    winding shall be earthed.

21. Bare hard-drawn copper wire may be used for distri-
    bution to consumers from either the three-phase trans-
    formers installed at the aforementioned four centres or from
    the single-phase and three-phase transformers that may be
    inserted at points along the transmission-line.

22. The voltage between the neutral wire and any of the
    outers shall approximate to 220 volts, and that between any
    two outers to 380 volts.

23. Primary and secondary wires are not to be run on
    the same poles.

24. The maximum declared pressure for lighting purposes
    (except arc lamps) shall not exceed 220 volts at any pair of
    terminals on a consumer’s premises. For power purposes
    motors may be connected across the three outers of the
    distribution system, and the maximum pressure between
    any pair of terminals shall not exceed 380 volts.

25. The low-tension electric-lighting lines and wires shall
    be aerial throughout, and shall be placed on one side only
    of any road or street along which they may run. Where
    telegraph or telephone lines exist in any street or road along
    which it may be desired to place electric-lighting lines the
    latter shall be run on the opposite side of the street or road
    to that on which the telegraph or telephone lines run, except
    by permission from the Electric Telegraph Commissioner.

After the opening of the system for the supply of energy,
an application shall be made for every further extension
through the Postmaster at Hawera, to the Superintendent
of Electric Lines for permission to extend, and in such
application particulars of the proposed extension shall be
given.

26. Where the erection of the electric-light line or wires
    necessitates the alteration of existing telegraph or telephone
    lines or wires, the expense of such alterations shall be borne
    by the above-named company.

27. 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, using resin
    as a flux, and must be protected against corrosion. The
    sectional area of all conductors from any distribution block
    on the consumer’s premises 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.

28. The sectional area of the conductor in any electric
    line for distribution purposes laid or erected in any street
    shall not be less than the area of a circular wire one hundred
    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.

29. All material used for insulating electric lines or appa-
    ratus 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.

30. 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.

31. Every low-tension 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 company shall duly record the results of
    the tests of each main or section of a main.

32. The insulation of every complete low-tension distribu-
    tion-circuit used for the supply of energy, including all
    machinery, apparatus, and devices forming part of or in con-
    nection 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 suit-
    able means shall be provided for the immediate indication
    of leakage. Every leakage shall be remedied without delay.
    Every such circuit shall be tested for insulation at least
    once in every week, and the company shall duly record the
    results of the testings.

33. Tests for insulation of the secondary-supply circuits
    tapped off by single-phase or three-phase transformers along