Clearance around an electrical panel

Answer 1

The National Electric Code requires min. 3'0" there are several rules defined in section 110.26 of the NEC; for 600 volts or less it is: * left to right the minimum clearance is 30" or the width of the equipment, whichever is larger * in height, there should be 6' 6'' minimum height to stand in front of the equipment (exception for dwelling units for panels 200 amps or less) * the depth in front of the equipment varies depending on the voltage and surfaces of the opposite wall behind you: if the voltage is 150 volts to ground or less the depth of clearance is 30": as stated above; if the voltage is higher it depends of whether the opposite wall is insulated or not: if insulated the depth is 3' 6", if not insulated (such as cement block) the depth is 48"

I refer to these rules as the "refrigerator rule": the clearance in front of the equipment in question requires a dedicated clear space roughly the size of a large refrigerator