Code Hunter — Clearance (2017 NEC)

1. For battery racks, there shall be a minimum clearance of __________ between a cell container and any wall or structure on the side not requiring access for maintenance.

2. Overhead service conductors, where not in excess of 600 volts, nominal, shall have the following minimum clearance from final grade:

3. Electrical equipment provided with _________ openings shall be installed so that walls or other obstructions do not prevent the free circulation of air through the equipment.

4. Overhead spans of _________ conductors and _________ multiconductor cables shall have a vertical clearance of not less than 2.7 m (8 ft 6 in.) above the roof surface.

5. Boxes that enclose devices or utilization equipment that projects more than __________ rearward from the mounting plane of the box shall have a depth that is not less than the depth of the equipment plus 6 mm (¼ in.).

6. For other than a totally enclosed switchboard or switchgear, a space not less than __________ shall be provided between the top of the switchboard or switchgear and any combustible ceiling, unless a noncombustible shield is provided between the switchboard or switchgear and the ceiling.

7. Luminaires installed in exposed or concealed locations under metal-corrugated sheet roof decking shall be installed and supported so there is not less than 38 mm (1 ½ in.) measured from the __________ of the roof decking to the top of the luminaire.

8. In a concealed knob-and-tube wiring system, a minimum clearance of 3 inches must be maintained between conductors.

9. Transformers with ventilating openings are required to be installed so that the openings are not blocked by walls or other obstructions.

10. Wiring located above heated ceilings shall be spaced not less than 100 mm (4 in.) above the heated ceiling.