2558
THE NEW ZEALAND GAZETTE.
[No. 65

Arc Lamps.

47-61. Where an open type arc lamp is used—
(a) When the lamp is fixed, the floor immediately underneath the lamp shall, unless of incombustible material, be protected from falling particles of carbon by an incombustible covering; and
(b) When the lamp is portable, either the floor, unless of incombustible material, shall be protected, in every place where the lamp may be used, by an incombustible covering, or a tray of adequate size and made of incombustible material shall be permanently fixed to the underside of the lamp.

Plugs, Sockets, and Adaptors.

47-71. (1) Every plug-socket shall be controlled by a switch in the live conductor, save that in the case of sockets not exceeding 10-amperes capacity where the plug and socket is of a type approved for the purpose the switch may be omitted on an alternating current subcircuit.
(2) Every socket used for a motor exceeding ½ horse-power shall be controlled by a switch.

47-72. All plug-sockets shall be mounted in such a manner that dirt and dust cannot readily accumulate therein.

47-73. In the case of two-pin non-reversible type plug-sockets the neutral conductor shall be connected to—
(a) The slot on the radial line; or
(b) The outer contact where the contacts are concentric; or
(c) The larger contact where the pins are of different size; or
(d) The circular contact where the pins are of different shape.

47-74. In the case of three-pin plug-sockets,—
(a) The earthing-lead shall be connected to—
(i) The slot on the radial line; or
(ii) The contact for the longer pin where the pins are circular; or
(iii) The outer shell where the plug has two pins and an outer metal shell;
(b) Assuming the terminal of the socket to which the earthing-lead is connected to be called number one and the other terminals numbered consecutively in a clockwise direction a live conductor shall be connected to terminal number two and the neutral (or other) conductor to terminal number three:
(c) Where any plug-socket in any installation is fixed in a position in which earthing is necessary to comply with the requirements of these regulations three-core flexible cord shall be used on all appliances in such installation which may require to be earthed.

47-75. Plugs and sockets exposed to rain, drip, or externally condensed moisture shall be weatherproof.

47-76. In every position where earthing of apparatus is necessary to comply with the requirements of Regulations 54-01 and 54-02 hereof, the plug-socket shall be equipped with a contact for earthing purposes and such contact shall be earthed.

Wooden Blocks.

47-81. (1) Every wooden base block shall—
(a) Be made of thoroughly seasoned suitable timber and be of robust construction; and
(b) Be rendered impervious to moisture when mounted in a position liable to be damp; and
(c) For surface conduit work, be counter-bored in such a manner as to receive the conduit but so as to prevent it from projecting within the recess of the block; and
(d) Be securely fixed.
(2) Wooden blocks shall not be used for direct-current installations where one of the supply conductors is earthed, unless the permission of the electrical supply authority is first obtained.

PORTABLE APPLIANCES, FITTINGS, AND ACCESSORIES.

47-91. Where portable appliances, fittings, or accessories are used the pressure between any two points in one room or compartment shall not exceed 250 volts, unless—
(a) The appliances, fittings, or accessories between which there may be a higher pressure are so situated that they cannot be brought within 6 ft. of each other; or
(b) The metal frames and sheathings of all such appliances, fittings, and accessories are earthed; or
(c) Such appliances, fittings, and accessories are of the all-insulated type.

47-92. Every portable appliance used in a wet situation shall be supplied at extra-low pressure.

47-93. No domestic portable appliance shall be used on a pressure normally in excess of 250 volts to earth.

47-94. Portable appliances and fittings shall be connected to the fixed wiring by means of plugs and sockets, connectors, or adaptors of suitable capacity.

PART 48.—MOTORS AND CONTROL GEAR.

Motors.

48-01. Motors shall, wherever possible, be placed in well ventilated spaces in which inflammable or explosive dust or gas is not likely to accumulate. Where this is not practicable the motors shall be of a type the use of which will not create an electrical hazard.

48-02. Motors located in situations where the temperature is such that the surrounding air does not provide sufficient cooling to prevent electrical hazard shall be of special construction to provide for this condition, or alternatively shall be provided with suitable ventilation taken from a source of cool air supply, and the air-intakes shall be guarded against the admission of dirt or moisture.

48-03. Motors shall, wherever possible, be placed in positions in which they are not normally exposed to risk of mechanical injury or to damage from water, steam, oil, or excessive dust. Motors necessarily exposed to such conditions shall be of suitable types as specified in British Standard Specification No. 168 or its equivalent.

48-04. Adequate precautions shall be taken in the installation of every motor as will ensure immunity from electrical hazard.

CONTROL OF MOTORS.

48-11. Every motor shall be provided with efficient means 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 a system having a multiple-earthed neutral, it shall not be necessary to disconnect the neutral.

48-12. Every motor shall be provided with an efficient switch or circuit-breaker for starting and stopping the motor, so placed as to be easily and safely operated by the person controlling the motor. Such switch or circuit-breaker may be embodied in the starting or controlling device used with the motor.

48-13. (1) Every motor having a rating exceeding ½ horse-power for direct current or 3 horse-power for alternating current shall be provided with—
(a) Means for automatically opening the circuit if the supply pressure falls sufficiently to cause the motor to stop; and
(b) In the case of direct current motors, means for limiting the amount of current taken when starting and accelerating; and
(c) In the case of alternating current motors in locations where the electrical supply authority so requires, means for limiting the amount of current taken when starting and accelerating to such reasonable value as the electrical supply authority may require.
(2) Every motor having a rating exceeding 3 horse-power shall be provided with an automatic overload release in each live conductor. In the case of alternating current motors such release shall be of the time-lag type.

48-14. Except where a double-throw starting switch is used every motor having a rating exceeding ½ horse-power and not exceeding 3 horse-power shall, when the starting current exceeds twice full-load current, be provided in each live conductor with—
(a) A circuit-breaker equipped with a time-lag automatic overload release; or
(b) A time-lag cut-out.
Where such circuit-breaker or cut-out also protects the subcircuit, the subcircuit circuit-breaker or cut-out (as the case may be) prescribed by Regulation 22-25 hereof may be omitted.

RESISTANCES AND CONTROL-GEAR.

48-21. Nothing in Regulations 48-22 and 48-23 hereof shall apply to apparatus having a capacity of less than 60 watts.

48-22. (1) All resistances and control gear shall, as far as possible, be placed—
(a) In positions in which they will not be exposed to risk of mechanical injury or to damage from water, steam, or oil; and
(b) In well ventilated spaces in which inflammable or explosive dust or gas is not likely to accumulate.
(2) Where necessarily exposed to such conditions as aforesaid, resistances and control gear shall be completely enclosed; and if liable to be exposed to inflammable or explosive dust or gas, control gear shall be flame-proof.

48-23. Adequate precautions shall be taken in the installation of every resistance as will ensure immunity from electrical hazard.

PART 49.—ELECTRIC LIFTS.

49-01. The supply of power to every lift, other than a service-lift, shall be taken direct from the main switchboard by means of a submain or subcircuit to which no lighting, heating, or other power device is connected.