Clearances

Different types of electrical equipment require various clearances from the ground, from building openings, and above roofs.

From Ground

Open conductors of not more than 600 volts, nominal, must conform to the minimum clearances specified in 29 CFR 1926.404. Requirements differ by distance, voltage, and conditions.

From Building Openings

Conductors must have a clearance of no less than three feet from windows that are designed to be opened, doors, fire escapes, and similar locations. However, conductors that run above the top level of a window may be less than three feet from the window.

Above Roofs

Overhead spans of conductors accessible to employees must meet certain vertical clearances, such as:

• No less than eight feet above a roof surface for insulated conductors
• No less than 10 feet vertical or diagonal clearance for covered conductors
• No less than 15 feet for bare conductors

Situation-specific clearance requirements are set out in 29 CFR 1926.404.

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