Automatic circuit breakers

85.36 - Electrical apparatus for switching or protecting electrical circuits, or for making connections to or in electrical circuits (for example, switches, relays, fuses, surge suppressors, plugs, sockets, lamp-holders and other connectors, 'unction boxes), for a voltage not exceeding 1,000 volts; connectors for optical 'f~bres,optical fibre bundles or cables. 8536.10 - Fuses 8536.20 - Automatic circuit breakers 8536.30 - Other apparatus for protecting electrical circuits - Relays : 8536.41 - - For a voltage not exceeding 60 V 8536.49 - - Other 8536.50 - Other switches - Lamp-holders, plugs and sockets : 8536.61 - - Larnp-holders 8536.69 - - Other 8536.70 - Connectors for optical fibres, optical fibre bundles or cables 8536.90 - Other apparatus This heading covers electrical apparatus for a voltage not exceeding 1,000 volts generally used for dwellings or industrial equipment. However, heading 85.35 covers the apparatus described below for a voltage exceeding 1,000 volts. This heading also covers connectors for optical fibres, optical fibre bundles or cables. The heading includes : (I) APPARATUS FOR SWITCHING ELECTRICAL CIRCUITS consist essentially of devices for making or breaking one or more circuits in or for switching from one circuit to another; they may be known as ., accordin to the number of switch circuits goley es change-over etc switc es and relays. K (A) The switches of this heading include small switches for use in radio apparatus, electrical instruments, etc., switches of a kind used in domestic electrical wirin (e.g., tumbler i? switches, lever o erated switches, rotary switches, pendant switches, ush utton switches) I cam switches, and switches L r industrial ap lication (such as, limit switc? es, microswitches and proximity switc es). E Switches operated by the opening or closing of a door and automatic thermo-electric switches (starters) for starting fluorescent lamps are classified here. Other examples classified here include electronic AC switches consisting of optically coupled input and output circuits (insulated thyristor AC switches); electronic switches, electronic switches, consisting of a transistor and a logic for a voltage not exceedin 1,000 volts; and electrofor a current not exceeding 1 amps (toggle switch). ? Electronic switches which operate by contactless means, using semiconductor components (e.g., for transistors, thyristors, integrated circuits). Door locks which themselves incorporate a switch are excluded (heading 83.01). (B) Change-over switches are used to connect one or more lines to one or more other lines. In the simplest type one line is connected to a central point which, by means of a moving arm, can be connected to any one of the other lines. More complicated a paratus of this t e includes starting switches for electric motors, and control gear for e ectric vehicles. g e s e often include not only the switching gear, but also a number of resistors to be switched in or out of the circuit as required (see Explanatory Note to heading 85.33). f The heading also covers complicated switching-units used in radio or television sets, etc. (C) Relays are electrical devices by means of which the circuit is automaticall controlled by a change in the same or another circuit. They are used, for example, in te ecommunication apparatus, road or rail signalling apparatus, for the control or protection of machine-tools, etc. The various types can be distinguished by, for example : (1) The electrical means of control used : electromagnetic relays, errnanent magnet relays, thermo-electric relays, induction relays, electro-static re ays, photoelectric relays, electronic relays, etc. f (2) The predetermined conditions on which they operate : maximum current relays, maximum or minimum voltage relays, differential relays, fast acting cut-out relays, time delay relays, etc. Contactors, which are also considered as relays, are devices for making and breakin electrical circuits, which automatically reset without a mechanical loclung device or han operation. They are generally operated and maintained in an active state by an electric current. f (11) APPARATUS FOR PROTECTING ELECTRICAL CIRCUITS The heading includes fuses. These normally consist of a device in which a length of fuse wire is incorporated (or can be incorporated so that, when they are inserted in the circuit, the fuse wire will melt and so break the circuit if e current increases dan erously, They v a r ~ considerably in design according to the type of circuit and current for whicf the are intende Cartridge fuses consist of a tube containin the fuse wire in contact with meta caps at the ends; other fuses consist of a base or socket @or inco oration in the line), and a connectin piece (which may be screwed into the socket or pushe?in between spring contacts) on wkch the fuse wire is mounted. The heading covers the corn lete fuse, w t h or without wire. Sockets and connectin ieces resented separately are also c assified here exce t those who11 of insulating materia f?art %om any minor corn onents of metal inco orate during moulJng solely for py,oses o assembl ) (heading 85. 7). Fuse wire is class1 led according to its constituent matena but short len& of fuse wire with loops or other means of connection so as to be ready for use remain in this heading. a r f S 9 i' The heading includes other devices for preventing overload ,of circuits (e-g., electro-magnetic devices which automatically break the circuit when the current exceeds a certain value). The heading also excludes constant voltage transformers (heading 85.04) and automatic voltage regulators (heading 90.32). (III) APPARATUS FOR MAKING CONNECTIONS TO OR IN ELECTRICAL CIRCUITS This apparatus is used to connect together the various parts of an electrical circuit. It includes : (A) Plugs, sockets and other contacts for connectin a movable lead or apparatus to an installation which is usually fixed. This category inc udes : f (1) Plugs and sockets (including those for connectin two movable leads). A plug may have one or more pins or side contacts which matc corresponding holes or contacts in the socket. The rim or one of the pins may be used for earthing purposes. f (2) Sliding contacts such as brushes for motors and current-collectors for electric traction vehicles, lifting appliances, etc. (overhead or tlzlrd rail collectors, etc.) other than such articles of" carbon " or graphite heading 85.45). They may consist of block metal, wire cloth or laminated str~, an remain in this heading even when coated with an external lubricating layer o graphite. P d (3) Lam or valve sockets and lamp-holders. Certain lamp-holders are in the form of candt'es for mounting in candelabra or are designed to form a bracket against a wall; these remain classified here provided their main function is to act as lamp-holders. Plugs and sockets, etc., assembled with a length of wire are excluded (heading 85.44). (B) Other connectors, terminals, terminal strips, etc. These include small squares of insulating material fitted with electrical connectors (dominoes), terminals which are metal parts intended for the reception of conductors, and small metal arts designed to be fitted on the end of electrical wirmg to facilitate electrical connection gpade terminals, crocodile clips, etc.). Terminal strips consist of strips of insulating material fitted with a number of metal terminals or connectors to which electrical wirin can be fixed. The heading also covers tag strips or anels; these consist of a number o metal tags set in insulatin material so that electric'!a wires can be soldered to them. Tag strips are used in radio or ot er electrical apparahrs. f g, (C) Junction boxes. These consist of boxes fitted internally with terminals or other devices for connecting together electrical wires. Boxes not fitted with means of electrical connection or provis~onstherefor, are excluded and are classified according to their constituent material. (IV) CONNECTORS FOR OPTICAL FIBRES, OPTICAL F'IBRE BUNDLES OR CABLES For the purpose of heading 85.36, "connectors for optical fibres, optical fibre bundles or cables" means connectors that sim ly mechanically align optical fibres end to end in a di ital line system, They perform no ot er function, such as the amplification, regeneration or mo8;fication of a signal. Connectors for o tical fibres, without cables, remain classified in this heading but those connectors for optical I res with cables are excluded (heading 85.44 or 90.01). ! f% PARTS Sub'ect to the general provisions regarding the classification of parts (see the General :z&Jgti238. Note to Section XVI), parts of the apparatus of this heading are classified in The heading also excludes : (a) Non-linear voltage resistors (varistorsNDR) used as voltage controllers (heading 85.33). (b) Assemblies (other than simple switch assemblies) of the apparatus mentioned above (heading 85.37). (c) Semiconductor diodes used as voltage controIlers (heading 85.41).