Side clearance: There should be a minimum of 30 inches of clearance from the sides of all electrical equipment, but in no case less than the width of the equipment itself. This is referred to as the side-to-side working space. Note that all panel doors and access doors must be able to open a minimum of 90 degrees. The chart above illustrates the. High voltage overhead lines constitute a foundational element of modern electrical transmission and distribution systems, enabling the movement of large quantities of electrical energy across extensive geographic distances. These systems typically operate at voltages exceeding 34. 5 kV and are. Insulation standards for isolated components (such as an isolated gate driver) do not address CPG and CLR.