2546
THE NEW ZEALAND GAZETTE.
[No. 65

(3) In the case of imported portable appliances in which
the flexible cord is connected by the maker, the maker’s
name, or registered trade-mark, or registered trade-name,
and grade of insulation need not be so marked, provided
such appliance is branded with the manufacturer’s name, or
registered trade-mark, or registered trade-name or otherwise
readily identifiable.

PROTECTIVE COVERING OF CONDUCTORS.

23-41. The types of protective covering prescribed by
Regulations 23-42 to 23-71 (both inclusive) hereof are hereby
declared to be approved types for the purposes of these
regulations and these types, or such other types as may
from time to time be approved, shall alone be employed.

RUBBER-INSULATED CABLES.

23-42. Rubber-insulated cables other than flexible cables
shall be provided with some one of the following coverings :—
(a) Taped as in paragraph (a) of clause (3) of Regulation
23-12 hereof and compounded ; or
(b) Braided as in Regulation 23-51 hereof ; or
(c) Bedded and armoured, with or without serving or
braiding over the armour ; the bedding, armouring,
and serving or braiding (if any) shall be in accordance
with British Standard Specification No. 7 or its
equivalent ; or
(d) Covered with tough rubber compound in accordance
with the requirements of Regulation 23-71 hereof ;
or
(e) Covered in accordance with the requirements of Regula-
tion 23-43 hereof.

RUBBER-INSULATED CABLES OR PAPER-INSULATED CABLES.

23-43. Rubber-insulated cables or paper-insulated cables
other than flexible cables shall be provided with some one of
the following coverings :—
(a) Sheathed with a closely fitting seamless covering of
commercially pure lead having a smooth exterior
surface and of a uniform radial thickness in accord-
ance with British Standard Specification No. 7 or
British Standard Specification No. 480 (as the case
may be) or their equivalent ; or
(b) Lead-covered as in the last preceding paragraph, and
bedded and armoured, with or without serving or
braiding over the armour ; the bedding, armouring,
and serving or braiding (if any) shall be in accordance
with British Standard Specification No. 7 or British
Standard Specification No. 480 (as the case may be)
or their equivalent ; or
(c) Sheathed with a closely fitting seamless covering contain-
ing not less than 95 per cent. of commercially pure
lead (the remainder consisting of rarer metals) and
in other respects complying with paragraph (a) of
this regulation.

BRAIDING.

23-51. Braided cables shall have an exterior braiding of
hemp, cotton, jute, or other suitable material, thoroughly
impregnated with a protective compound that will not have
any deleterious action on the rubber or armouring, as the case
may be.

FLEXIBLE CABLES AND CORDS.

23-61. Flexible cables and flexible cords shall be provided
with some one of the following coverings :—
(a) Braiding of natural silk or of artificial silk ; or
(b) Glace-cotton braiding ; or
(c) Hemp, cotton, jute, or other suitable braiding thoroughly
compounded ; or
(d) Wire armouring, comprising a flexible braiding of gal-
vanized steel or bronze wire in addition to the
covering specified in paragraph (c) of this regulation ;
or
(e) Hard-cord braiding, plain or impregnated, in addition
to the covering specified in paragraph (c) of this
regulation ; or
(f) Tough rubber compound in accordance with Regula-
tion 23-71 hereof ; or
(g) Flame-resisting braiding ; or
(h) Varnished cotton or silk waterproof braiding ; or
(i) Thin tough rubber compound over twisted conductors ;
or
(j) Rubber compound with braiding overall ; or
(k) Thin tough rubber compound over conductors made
up to a circular or oval section with hemp, cotton,
or jute filling.

TOUGH RUBBER SHEATHING.

23-71. Tough rubber compound when used as a protective
covering shall—
(a) Form a closely fitting sheath filling the external
irregularities of the laid-up cores in the case of
twin and multicore cables or flexible cords and
concentric with the conductor in the case of single
core ; and
(b) Be waterproof and capable of offering a high degree of
resistance to abrasion and decay ; and
(c) Have a radial thickness not less than that specified in
British Standard Specification No. 7, or Table VIII
in Division VII hereof, as the case may be.

ALTERNATIVE MATERIAL OR TYPES.

23-81. If it is desired to use a type of cable or flexible cord
otherwise than specified in Regulations 23-01 and 23-12 to
23-71 (both inclusive) hereof, permission shall be obtained
from the Chief Electrical Engineer for its use provisionally
or otherwise. The Chief Electrical Engineer may require to
be submitted samples and/or a report from a recognized
testing authority (such as the National Physical Laboratory
in England) as to the behaviour, properties, and life of the
materials employed.

IDENTIFICATION OF CABLES AND FLEXIBLE CORDS.

23-91. (1) All insulated cables other than flexible cables
shall, except as provided in clause (3) of this regulation, be
rendered distinguishable by means of the following colours :—
A.C. three-phase and D.C. three-wire systems of wiring—
(a) Live conductor—Red, yellow, or blue.
(b) Neutral, earthed conductor or middle-wire—Black.
D.C. two-wire systems of wiring—
(c) Positive—Red, yellow, or blue.
(d) Negative—Black.
A.C. two-wire non-earthed systems of wiring—
(e) One conductor—Red, yellow, or blue.
(f) Other conductor—Black.
(2) All insulated flexible cords and all insulated flexible
cables shall, except as provided in clause (3) of this regulation,
be coloured in such a manner that each conductor may be
readily identified.
(3) This regulation does not apply to any three-core cable
used solely for three-phases or to any conductor used as
an aerial conductor or enclosed within a current-using device
or used for high pressure or extra-high pressure in connection
with luminous-discharge-tubes.
(4) For the purposes of this regulation a conductor shall
be deemed to be alive up to the lamp or other current-using
appliance when the switch is in the “ on ” position.

PART 24.—CONDUIT AND CASING.

SCREWED CONDUIT AND FITTINGS.

24-01. Screwed conduit and fittings shall comply with the
following requirements :—
(a) The conduit shall be made in accordance with British
Standard Specification No. 31 and shall be of heavy
gauge and welded or solid drawn.
(b) The conduit fittings, other than boxes, shall be made in
accordance with British Standard Specification No. 31.
(c) The conduit boxes shall be—
(i) Where applicable made in accordance with
British Standard Specification No. 31 :
(ii) Rectangular boxes of sheet steel or other
approved metal, in either case having a minimum
thickness of 0·0625 in. (¹⁄₁₆ in.) :
(iii) Cast-iron terminal boxes specially designed
as part of a complete accessory, and where such
boxes are not malleable cast-iron they shall be
approved.
(d) The screwed portion of bell-mouths and other outlets
shall be provided with a taper thread and shoulder
to prevent the conduit projecting, or shall be of
the length specified in British Standard Specifica-
tion No. 31.
(e) Bell-mouths and other outlets shall be of robust con-
struction.

WOOD CASING.

24-11. Wood casing for enclosing cables shall be of well-
seasoned timber, and shall be so constructed that the width
of the fillet between the grooves is not less than ¼ in. and
the thickness of the wood everywhere else not less than ⅜ in.