JULY 12.] THE NEW ZEALAND GAZETTE. 2409
usage in service, and so arranged that the cover will automati-
cally close over the contacts when the plug is withdrawn.
185. The bases of sockets shall be of tough non-ignitable,
non-conducting, non-hygrosco plsc material other than haro-
wood. The contacts shall be of spring-clip type, or such
other type as may be approved by the Chief Electrical Engineer.
186. The covers of sockets and plugs shall be made of
heat-resisting insulating material other than hardwood, or of
rigid metal, which shall be kept well clear of all live parts,
or provided with an insulating-lining.
187. (1) Weather-proof plugs and sockets shall be used
wherever exposed to rain, drip, or externally condensed
moisture.
(2) Such accessories shall be of specially robust construction,
and be provided with efficient means to keep the sockets
weather-proof when the plug is removed therefrom. When a
loose cover is employed for this purpose it shall be anchored
to the socket by means of a chain.
(3) When the plug is inserted in its socket, the combined
fitting and its interlocking-switch (if any) shall also be
weather-proof.
188. If concentric sockets are used on an earthed concentric
system of wiring, the centre contact of the socket shall be
connected to the insulated conductor.
189. Where tough rubber-sheathed flexible cord is used, a
suitable clamp shall be provided to grip the protecting
covering of the flexible cord.
190. When sockets and plugs have provision for earthing,
the current-carrying capacity of the earthing-contact shall
comply with the requirements of Part XI hereof with respect
to earthing.
191. In places where petrol-driven conveyances are stored
or repaired, plugs and sockets shall be placed not less than
5 ft. above the floor-level unless an interlocked plug and
gas-tight switch is used.
192. (1) Adapters for use in lamp-holders shall be con-
structed of tough non-ignitable, non-conducting, non-hygro-
scopic material other than hardwood.
(2) Adapters for use in screw holders shall be of one or
other of the following types, namely—
(a) Combined adapter with pull-out plug;
(b) Adapter with a loose screw to prevent twisting of the
flexible conductor.
ELECTRIC SIGNS.
193. Every electric sign shall comply with the following
requirements:
(a) It shall be readily accessible for inspection and atten-
tion.
(b) The sign shall be connected to the main supply by
independent wiring, and shall be controlled by a
fuse and switch on each live conductor. When more
than one switch is required the switches shall be
linked.
(c) Where elaborate switching and flashing apparatus is
installed, a special non-ignitable enclosure shall be
provided.
(d) If fixed in the open air—
(i) It shall be weather-proof, or, alternatively, the
wiring and lamp-holders shall be weather-proof.
(ii) Only non-ignitable materials shall be used in
its construction, except for letters and designs, for
which hardwood is permissible.
(iii) All external wiring shall be of Class R,
Class S, or Class T, as specified in Part III of the
Second Schedule hereto, and in the case of Class T
the conduits shall be galvanized.
(iv) External electric outline lighting, when the
lamp-holders are not enclosed, or of the weather-
proof type, shall be supplied at extra-low pressure.
(v) For electric signs, outline, and decorative
wiring, when in use outside a building, the final
subcircuits shall not exceed 10 amperes.
PART VII.—MOTORS, CONTROL GEAR AND LIFTS.
MOTORS.
TYPES.
194. Motors may be of any of the types enumerated in
British Standard Specification No. 168, or of the immersible
type, and all motors rated at more than l brake horse-power
shall conform in all respects to that specification.
195. Terminals of motors shall be so guarded that they
cannot be accidentally touched or short-circuited.
POSITION AND SAFETY PRECAUTIONS.
196. Motors shall, wherever possible, be placed in well-
ventilated spaces in which inflammable gases cannot accumu-
late. Where that is not practicable the motors shall be of
the flame-proof or pipe-ventilated type, with inlet and outlet
connected to the outer air.
197. Motors fixed in situations in which the surrounding
air exceeds the limit of temperature permitted for the cooling
air in the appropriate British Standard Specification shall be
of special construction, or, alternatively, of the pipe-ven-
tilated, forced-draught, or induced-draught type, connected by
ventilating-ducts to a source of cool-air supply.
198. Motors shall, wherever possible, be placed in positions
in which they are not exposed to risk of mechanical injury
or to damage from water, steam, or oil. Motors necessarily
exposed to such conditions shall have suitable types of enclos-
ing frames selected from the standard “types of enclosure”
specified in British Standard Specification No. 168.
199. Pipe-ventilated, forced-draught, and induced-draught
motors shall be supplied with air as cool as possible, and the
air intakes shall be guarded against the admission of dirt or
moisture.
200. No unprotected woodwork or other combustible ma-
terial shall be within a distance of 12 in. (measured horizon-
tally) from or within 4 ft. (measured vertically) above any
motor, unless such motor be of the totally enclosed, flame-
proof, or pipe-ventilated type with inlet and outlet connected
to the outer air. A metal plate or tray extending 12 in.
beyond the base of the machine shall be placed under every
open-type machine which is mounted on or over a floor
consisting of wood or other combustible material.
201. (1) Where conductors are run in conduit, or where
metal-sheathed cables are used, the conduit or metal sheath,
as the case may be, shall terminate in and be properly secured
to the motor terminal box; provided that flexible metallic
conduit may be used between screwed conduit and the motor
terminal box.
(2) Trailing cables used in connection with portable motors
shall have their protective sheathing terminating in and
properly secured to the motor terminal box.
CONTROL OF MOTORS.
202. Every motor shall be controlled by a switch or circuit
breaker suitably placed and so connected that the motor and all
apparatus in connection therewith may be isolated from the
supply : Provided that in the case of supply from a system
having a multiple earthed neutral, it shall not be necessary
to disconnect the neutral.
203. (1) Every motor shall be provided with an efficient
switch or circuit-breaker for starting and stopping, so placed as
to be easily operated by the person controlling the motor, and
every motor having a rating exceeding 4 horse-power for
direct current, or 3 horsepower for alternating current, shall
in addition be provided with—
(a) Means for automatically opening the circuit if the
supply-pressure falls sufficiently to cause the motor
to stop:
(b) In the case of direct-current motors, a starter or switch
for limiting the amount of current taken when
starting and accelerating:
(c) In the case of alternating-current motors, a starter or
switch which shall limit the amount of current
taken, when starting and accelerating, to the value
(if any) required by the electrical supply authority:
(2) Every motor rated at over 3 horse-power shall be pro-
vided with an approved time-lag automatic over-load release
in addition to the low-voltage release.
204. (1) Motors of 3 horsepower or under shall, when the
starting-current is over 200 per cent. of full-load current, be
provided with time-lag cut-outs or automatic time-lag release
approved by the Authorized Inspector, in addition to the
circuit fuses.
(2) The number of such devices to be provided for each
motor shall be not less than—
(a) D.C. or A.C. single-phase . . . . One.
(b) Two-phase or three-phase . . . . Two.
205. In every place in which a machine is being driven by
a motor the control of which is inaccessible from the machine,
and where no means for mechanically stopping the machine
exist, there shall be provided some readily accessible means
for switching off the motor.
RESISTANCES AND MACHINE-CONTROL GEAR.
68. GENERAL CONSTRUCTION.
206. Nothing in Regulations 207 to 212 hereof shall apply
to apparatus having a capacity of less than 60 watts.
207. The general construction of all resistances and machine-
control gear shall be in accordance with the appropriate
British Standard Specifications.