DIN EN 60691:2017-04

This International Standard is applicable to thermal-links intended for incorporation in electrical appliances, electronic equipment and component parts thereof, normally intended for use indoors, in order to protect them against excessive temperatures under abnormal conditions. Thermal-links, defined as non-resettable devices functioning once only without refunctioning, are widely applied for the thermal protection of equipment in which, under fault (abnormal) conditions, one or more parts may reach hazardous temperatures. As thermal-links have several aspects in common with miniature fuse-links and they achieve a comparable degree of protection, this standard aims to define some basic requirements for for thermal-links. This standard may be applicable to thermal-links for use under conditions other than indoors, provided that the climatic and other circumstances in the immediate surroundings of such thermal-links are comparable with those in this standard. This standard may be applicable to thermal-links in their simplest forms (for example, melting strips or wires), provided that molten materials expelled during function cannot adversely interfere with the safe use of the equipment, especially in the case of hand-held or portable equipment, irrespective of its position. This standard is applicable to thermal-links with a rated voltage not exceeding 690 V a.c. or d.c. and a rated current not exceeding 63 A. The objectives of this standard are to establish uniform requirements for thermal-links, to define methods of test, to provide useful information for the application of thermal-links in equipment. This standard is not applicable to thermal-links used under extreme conditions such as corrosive or explosive atmospheres. This standard is not applicable to thermal-links to be used in circuits on a.c. with a frequency lower than 45 Hz or higher than 62 Hz. Adequate protection of the equipment against excessive temperatures not only depends upon the properties of the thermal-link but also to a large extent upon the mounting of the thermal-link in the equipment. Therefore, in addition to good engineering practice, the requirements of the application guide shall be considered. Thermal-links shall have adequate electrical and mechanical strength and shall be constructed so as to withstand all conditions of handling likely to be encountered during mounting and normal use, when used within the requirements of this standard. When a thermal-link changes its state of conductivity, no arc or flame shall be maintained, nor material expelled, that might impair the surrounding area or otherwise create a risk of electric shock or fire. After it has functioned, the thermal-link shall not be damaged when subjected to temperatures not exceeding Tm, in such a way that the safety of the equipment with regard to risk of electric shock hazard and electrical breakdown is impaired. Instructions for mounting given by the manufacturer of the thermal-link shall be followed, especially in the case where thermal-links are provided with a coating or used in impregnated windings. The responsible committee is DKE/K 663 "Gerätesicherungen (G-sicherungen)" ("Device fuses (miniature fuses)") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.