SEPT. 6.] THE NEW ZEALAND GAZETTE. 2547

PART 25.—BELLS.

LOW PRESSURE ELECTRIC BELLS.

25-01. Every electric bell or buzzer operating directly on a low pressure subcircuit shall comply with the following requirements:—
(a) The current-carrying parts of the bell or buzzer shall be contained within a case which is not readily combustible; and
(b) The current-carrying parts of the bell or buzzer shall be efficiently insulated, otherwise than by wood; and
(c) All current-carrying screws and nuts of the bell or buzzer shall be effectively locked in such a manner as will preclude movement due to vibration; and
(d) The cover of the bell or buzzer, where fixed in any position accessible to unauthorized persons, shall be effectively secured to prevent unauthorized removal; and
(e) The cover of the bell or buzzer shall have clearly and permanently marked thereon in letters not less than 3/32 in. high the following: “230 VOLTS—DO NOT OPEN”; and
(f) Every bell or buzzer shall be fitted with a condenser across the spark gap.

PART 26.—CABLE SOCKETS AND OTHER CONNECTIONS.

CABLE SOCKETS.

26-01. Cable sockets shall where practicable be in accordance with British Standard Specification No. 91 or its equivalent, and in every case made of material which complies with the aforementioned specification, and of such a size that all strands of the conductor can enter the socket simultaneously.

BINDING-POSTS.

26-11. Binding-posts shall be fitted with a fine-thread screw and be tapped to a depth not less than the diameter of the screw.

JOINT-BOXES.

26-21. Every joint-box shall comply with the following requirements:—
(a) It shall be constructed wholly of material which is durable, not readily combustible, and non-absorbent, and all insulation shall be of permanently high electric strength and insulation resistance; and
(b) The live parts within such box shall be so arranged by suitable spacing or shielding with non-ignitable insulating material that conductors of opposite polarity or different phase cannot be readily short-circuited; and
(c) When used in damp situations it shall be weatherproof and moisture resisting; and
(d) When used with metal conduits it shall be of metal having a minimum thickness of 0·0625 in. (1/16 in.); and
(e) When used with Class II cables specified in Regulation 44-81 hereof it shall be made of non-ignitable material.

PART 27.—FITTINGS, APPLIANCES, AND ACCESSORIES.

FITTINGS.

27-01. All fittings shall be so constructed that—
(a) Passages for insulated conductors are of such size and so made as to avoid risk of abrasion; and
(b) There is no mechanical strain on any terminal; and
(c) Outlets are bushed or have well-rounded edges; and
(d) When hanging and exceeding 10 lb. in weight, they are suspended by a metal chain, rod, or tube of adequate strength, or by several flexible cords, in which case the weight on any one cord shall not be more than that specified in paragraph (c) of Regulation 45-21 hereof; and
(e) If of the enclosed type they are of such size or so designed as to avoid undue heating, and if so situated that the enclosing globe is liable to mechanical injury, it is protected by a suitable guard.

27-02. (1) Shades of inflammable material shall be kept free from contact with lamps and lamp-holders by means of suitable guards or supports.
(2) Celluloid or other highly inflammable material shall not be used for any shade, candle-tube, colour-screen, or in any position where it is likely to introduce an electrical hazard.

APPLIANCES.

27-11. (1) Every hand-lamp shall have the metal parts of the lamp-holder and any metal in contact therewith shrouded by insulation to prevent contact between such metal and the metal guard, or when the lamp-bulb (namely, the incandescent lamp) is in position and the guard is removed between such metal and the user.
(2) This regulation does not apply to a hand-lamp made entirely of metal provided with a watertight glass and earthed as provided in Regulation 54-01 hereof.

27-12. The handle of every hand-lamp (not being a hand-lamp made entirely of metal as specified in the last preceding regulation) shall be made of treated hardwood, or of some suitable insulating material capable of withstanding rough usage in service.

MEDICAL AND DENTAL APPLIANCES.

27-21. Medical and dental appliances in which any metal liable to become alive is, or which may be, in direct contact with the body of the patient shall be isolated by means of double-wound transformers or motor-generators or some other approved method from any submain or subcircuit which is connected to a service-main.

ACCESSORIES.

Ceiling-roses.

27-31. Ceiling-roses shall comply with the requirements of British Standard Specification No. 67, or shall be of such other types as may be from time to time approved.

Lamp-holders.

27-41. Every lamp-holder shall be of robust construction, and where it does not comply with a British Standard Specification the variation therefrom shall be within reasonable limits and so that no electrical hazard is created thereby.

27-42. No switch lamp-holder shall be used unless it is of an approved type.

Incandescent Lamps.

27-51. Incandescent lamps for ordinary lighting purposes shall comply with the appropriate British Standard Specification or its equivalent, and shall be provided with caps of a pattern as follows:—

Not exceeding 40 watts
{ Small Standard Bayonet (S.B.C.)
{ Standard Bayonet (B.C.),
{ Small Edison Screw (S.E.S.), or
{ Edison Screw (E.S.).

Above 40 watts and not exceeding 200 watts
{ Standard Bayonet (B.C.), or
{ Edison Screw (E.S.).

Above 200 watts and not exceeding 300 watts
{ Edison Screw (E.S.).

Above 300 watts
.. Goliath Screw (G.E.S.).

Mercury-vapour Lamps.

27-61. The connections to the terminals of the lamp-tube of every mercury-vapour lamp shall be so constructed that loosening of the contact or overheating cannot occur.

27-62. The resistance and solenoid of every mercury-vapour lamp shall be completely enclosed in a metal case, and any apertures in the case for purposes of ventilation shall be made only on the sides and be covered with fine wire gauze.

Plugs, Sockets, and Adaptors.

27-71. (1) Sockets shall be constructed so that the earthing pin (if any) of the plug can make contact only with the earthing terminal.
(2) The earthing pin and terminal shall be made distinguishable by tinning or otherwise.

27-72. Plugs and sockets shall be so constructed that no person can make accidental contact with live metal.

27-73. All plugs shall, except in the case of flexible cords having a protective covering prescribed by paragraphs (a) and (b) of Regulation 23-61 hereof, be constructed with provision for gripping the flexible cord or cable together with its protective covering or sheath to prevent any stress on the connections with the terminals.

27-74. Every plug-socket shall have a minimum rated capacity of 10 amperes.

27-75. Floor-sockets shall be fitted with a strong hinged close-fitting cover which is not readily combustible, which is capable of withstanding rough usage in service, and so arranged that the cover will automatically close over the contacts when the plug is withdrawn.

27-76. The bases of plugs and sockets shall be of material other than wood and such material shall be non-conducting, non-hygroscopic, and not readily combustible.

27-77. The covers of plugs and sockets shall be of heat-retarding insulating material other than wood, or of rigid metal, which shall be kept well clear of all live parts or be provided with an insulating lining.