IEC 60322 pdf download.Railway applications – Electric equipment for rolling stock – Rules for power resistors of open construction
1 Scope and object
This International Standard gives the rules for all power resistors (for example, braking, heating, snubber and filter) used in the power and auxiliary circuits on board rolling stock irrespective of the circuit and the type of vehicle where they are used. These resistors are generally of open construction and are used in polluted areas. The construction consists of resistor elements of grids, plates, strips, ribbons or wires. NOTE Certain of these rules may, after agreement between user and manufacturer, be used for electrical equipment installed on other vehicles such as mine locomotives, trolley buses, etc. This standard states – the characteristics of the resistors; – the service conditions with which the power resistors have to comply; – the tests intended for confirming that these conditions have been met and the methods to be adopted for these tests; – the information to be marked on, or given with, the resistors. This standard does not give requirements relating to general service conditions and general rules which are given in IEC 60077-1 . The object of this standard is to adapt the general rules given in IEC 60077-1 to power resistors for rolling stock in order to obtain uniformity of requirements and tests throughout the corresponding range of components and to avoid the need for testing to two different standards.
For the purpose of this International Standard, the definitions of IEC 60050(81 1 ) and the following definitions apply. 3.1 resistor element resistive conductor forming part of a resistor case or frame, usually in the form of grids, plates, strips, ribbons or wires and which may have intermediate tappings [IEV 81 1 -27-1 1 ] NOTE A resistor element is usually a removable assembly. 3.2 resistor general term used in this standard to designate any of the following forms of electrical resistance 3.2.1 resistor case resistor frame set of resistor elements assembled into a single structure [IEV 81 1 -27-1 2] NOTE 1 Resistor case is used for resistors having one or more resistor elements installed in an enclosure intended to form part of a forced air cooling duct. NOTE 2 Resistor frame is used for resistors having one or more resistor elements installed on a common frame for natural cooling in open air. 3.2.2 resistor section resistive circuit contained between two terminals, dedicated to an electrical function and connected to external equipment [IEV 81 1 -27-1 4 modified.] NOTE A resistor section may consist of a part or more than one resistor case or frame.3.3 double insulation two-stage insulation, the first between the live conductors and an intermediate frame and the second between the intermediate frame and the body of the vehicle [IEV 81 1 -27-1 5] NOTE 1 The intermediate frame is metallic (see annex A). NOTE 2 Double insulation in this context does not refer to double insulation used for protection against electric shock (see IEC 60364-4-41 ). 3.4 multi-stage insulation insulation system having more than one stage of insulation and an intermediate frame between consecutive stages NOTE 1 An insulation system having no more than one stage is termed “single insulation”. NOTE 2 For an insulation system having more than one stage, those stages other than the primary insulation are commonly known as “secondary insulation”. 3.5 primary insulation first stage of a multi-stage insulation between live conductors and the intermediate frame 3.6 functional insulation insulation between conductive parts which is necessary only for the proper function 3.7 basic insulation insulation applied to live parts to provide basic protection against electric shock (human safety) 3.8 maximum temperature (T m ) temperature of the hottest point of the resistor element under the specified conditions (duty, cooling, materials, etc.) 3.9 maximum permissible temperature temperature of the resistor element that can be withstood without any resulting damage (for example, permanent distortion) to any part of the resistor frame or case and its external connections