1, the general switch of the household distribution box can generally choose double-pole 32-63A small air switch or isolation switch. rcuit currents at 50 kA and below and rated maximum voltages of 5 and 15 kV. Advance 27 is ABB' switchgear is seismic certified IBC region D with importance factor of 1. air conditioning circuits generally choose. An outdoor electrical distribution box serves as the critical junction point where incoming power lines are split into multiple branch circuits for outdoor installations, parking lots, building exteriors, and industrial facilities. They provide positive, visible air gap isolation of equipment and line sections for safe examination, maintenance, and repair. It is called an air break switch because it makes use of air as the dielectric medium to suppress the electric arc produced during the closing and opening of the switch.