High voltage disconnector is widely used in power system, but the cold environment brings new challenges and difficulties to its operation and maintenance technology. To study the effect of cold conditions on its mechanical properties, and get the extraction to represent the characteristics of its running state, 550 kV anti-pollution double column single arm horizontal telescopic disconnector was selected as test sample, and the test platform was also established. Then, stator current, output shaft strain, and power output during the opening and closing process were measured at room temperature and low temperature. The test results shows that compared with room temperature, the variation rules of stator current, output shaft strain and output power do not change significantly in switching process under the cold conditions, but the amplitude all increase to different degrees, and the electromechanical flow curve cannot be used as the characteristic quantity to judge the mechanical state of the isolating switch.

disconnector,cold condition,mechanical properties,ultrahigh voltage