A switchgear or control gear includes: at least one first compartment; at least one second compartment; a plurality of main switchgear or control gear components including a main busbar system, a three position linear or rotational movement disconnector, a circuit breaker, and at least a first part of an insulated cable connection; and a plurality of auxiliary switchgear or control gear components including a disconnector drive and a circuit breaker drive. The plurality of main switchgear or control gear components are housed in the at least one first compartment. The plurality of auxiliary switchgear or control gear components are housed in the at least one second compartment. When one or more of the plurality of main switchgear or control gear components is energized, the at least one first compartment is hermetically sealable or maintainable at an internal air pressure greater than ambient air pressure.