Abstract: The article introduces the characters of stator & rotator construction and working state of drivers employed at light product station in the easy explosive zone of tank farm. The concrete data indicates that temperature raise will influence service life of asynchronous machine. It also gives a definition of temperature raise and points out that the allowance of temperature raise relies on insulating material used for stator which can be sorted into seven grades, Y、A、E、B、F、H、C, accordance with their unti-heat property. The relations among insulating material grades, environment temperature and temperature raise of drivers are stated clearly with some samples. It also introduces 3 methods (temperature test, thermometer test, direct current resistance test) employed in the temperature test process and concrete methods for operation, conversion and application. It points out that to judge the temperature of drivers by hand feeling is not scientific and sufficient, it also suggests that we should use thermometer test to judge temperature of small or medium sized asynchronous machines.