classe of transfer switching equipmentclasse de transfert de sourceKlassen der Netzumschalter转换开关电器的级别

transfer switch equipment based on mechanical switching devices, that do not need electrical power to hold the main contacts open or closed and capable of making, carrying, and breaking currents under normal circuit conditions including operating overload conditions, and making and withstanding short-circuit currents

transfer switch equipment based on mechanical switching devices and capable of making, carrying and breaking currents under normal circuit conditions including operating overload conditions, and making and breaking short-circuit currents

transfer switch equipment based on mechanical switching devices having only one position of rest, operating otherwise than by hand, and capable of making, carrying and breaking currents under normal circuit conditions including operating overload conditions