Installations built before the 1978 nec only require a minimum clearance of 2 ft in front of electrical equipment.
Electrical panel clearance door swing.
The width of working space in front of the electric equipment shall be the width of the equipment or 762 mm 30 in whichever is greater.
The width of panel or 0 762 meter which is greater.
There are specific clearance requirements in the code.
Clear height in front of panel 480v.
Clearance to ensure that an electrical panel can be accessed at all times during inspection maintenance or emergency osha has determined that the working space in front of the equipment must be at least 30 inches wide or the width of the equipment.
The 30 in wide rule has been used since the 1971 nec.
Nec says 3 on each side and 30 in front.
0 9 meter 3 ft clearance when facing other electrical panels 480v.
But then if the panel is 3 from the door the door would not block the panel.
Headroom clearance has been required since the 1965 nec.
A clearance of at least 3 feet is required for equipment using 120 to 250 volts.
0 9 meter 3 ft the width of the workingspace in front of the panel.
Updates to working space clearance around electrical equipment according to nec 2017.
In every case the width depth and height of the working space around electrical equipment must allow all equipment doors or hinged panels to open at least 90 degrees.
Graphically originally from mike holt.