How close to a box must EMT be strapped?

Within 3 feet of every box, cabinet, conduit body, or other termination, then every 10 feet along the run, per NEC 358.30(A). An exception allows up to 5 feet where structural members prevent closer fastening.

Does a 38 inch EMT run between two boxes need a strap?

Yes, but one strap near the middle satisfies the rule since it falls within 3 feet of both terminations. Connectors and boxes by themselves are not a securing means under 358.30.

How Many Feet Before the First Strap on EMT Conduit?

A user asked the app how far EMT can run before its first strap. NEC 2023 358.30(A) gives the rule: EMT must be securely fastened within 3 feet of every outlet box, junction box, device box, cabinet, conduit body, or other termination, and then supported at intervals not exceeding 10 feet. So the first strap lands within 3 feet of the box, not 10.

The short run question

A common field debate is a short piece of EMT joining two securely mounted boxes, say 38 inches apart. The 3 foot rule applies from each termination, so a single strap near the middle of that 38 inch stick sits within 3 feet of both boxes and satisfies the section with one fastener. The boxes themselves do not count as support for the raceway; 358.30 asks for the tubing to be secured, and connectors alone are not listed as a securing means. On a 24 inch nipple the same logic applies, one strap in the span covers both ends. Inspectors vary on very short nipples, and some accept unbroken nipples between rigidly mounted enclosures without a strap, but the letter of 358.30(A) still calls for securing within 3 feet of each termination, so plan on the strap.

The 5 foot exception

Where structural members make fastening within 3 feet impractical, the exception to 358.30(A) allows the distance to stretch to 5 feet from the termination. Think of a box mounted on a bar joist roof deck where the nearest steel is 4 feet away. Document the condition, because the exception is for framing that genuinely does not permit closer fastening, not for saving a strap.

Horizontal runs through framing

358.30(B) helps in stud and joist work: EMT run horizontally through openings in framing members counts as supported by those members, provided it is still secured within 3 feet of any termination. Bored holes on 16 inch centers are effectively free supports. Also keep the 10 foot interval honest on vertical runs; a strap at each floor line usually handles it in commercial work.

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