Q. When are overcurrent devices restricted from being installed?

A. These are the four key requirements you must keep in mind when installing overcurrent devices.

1) Overcurrent devices must not be exposed to physical damage [240.24(C)]. Note: Electrical equipment must be suitable for the environment, and consideration must be given to the presence of corrosive gases, fumes, vapors, liquids, or chemicals that have a deteriorating effect on conductors or equipment [110.11].

2) Overcurrent devices must not be located near easily ignitable material, such as in clothes closets [240.24(D)].

3) Overcurrent devices aren't permitted to be located in the bathrooms of dwelling units, dormitories, or guest rooms or guest suites of hotels or motels [240.24(E)]. In addition, the service disconnecting means must not be located in a bathroom, even in commercial or industrial facilities [230.70(A)(2)].

4) Overcurrent devices must not be located over the steps of a stairway [240.24(FC)]. Clearly, it’s difficult for electricians to safely work on electrical equipment that’s located on uneven surfaces such as over stairways.