IEC 60255-149:2013规定了热保护继电器的最低要求。本标准包括保护功能、测量特性和测试方法的规范。目的是通过测量流经设备的交流电流，为评估相关时间继电器建立一个通用且可重复的参考，该继电器可保护设备免受热损坏。补充输入通电量，如环境、冷却剂、顶油和绕组温度，可适用于本标准中规定的热保护规范。本标准涵盖了基于具有记忆功能的热模型的保护继电器。

IEC 60255-149:2013 specifies minimum requirements for thermal protection relays. This standard includes specification of the protection function, measurement characteristics and test methodologies. The object is to establish a common and reproducible reference for evaluating dependent time relays which protect equipment from thermal damage by measuring a.c. current flowing through the equipment. Complementary input energizing quantities such as ambient, coolant, top oil and winding temperature may be applicable for the thermal protection specification set forth in this standard. This standard covers protection relays based on a thermal model with memory function.