One of the robust, low-maintenance energy storage mechanisms of type H 29 EA is mounted on the base frame on which the three switch poles are installed. Hundreds of thousands of these devices have already been used successfully in the SwitchDisconnector H 22.
The EA energy storage mechanism operates with two torsion springs for quick-make and quick-break operation with trip-free release. Both torsion springs are tensioned when the switch is
closed. While the ON switch spring relaxes after tensioning and releases the energy for switching ON , the OFF switch spring remains tensioned and can be released by the tripping device, HV HBC fuse with pin triggering or manually for switching OFF.
With non-manual release the operating shaft remains in ON position and must be moved to the neutral position manually for reclosing. The actuation for wall-mounting devices can take
place via a linkage system operated by a lever or using any of the manual actuators given in or motorized actuator given in brochure 774, according to requirements and situation.