Scope and objectThis 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.NOTE 1 The equipment need not be designed to generate heat.NOTE 2 The effectiveness of the protection against excessive temperature logically depends upon the position and method of mounting of the thermal-link@ as well as upon the current which it is carrying.NOTE 3 Attention is drawn to the fact that the external creepage distances and clearances specified in Table 3 may in some cases be smaller than those required by certain appliance or equipment standards. In such cases@ additional means should be provided when a thermal-link is mounted in the equipment in order to adjust the creepage distances and clearances to the values required by the relevant equipment standard.This standard may be applicable to thermal-link 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 (e.g. 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 object of this standard isa) to establlish uniform requirements for thermal-links@b) to define methods of test@c) 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.