Expansion joints

[steve holt]

What authority has jurisdiction regarding the installation of electrical expansion joints at constuction expansion joints? NEC 300.7 covers the use of expansion joints due to temperature differentials, but I don't see anything on building movement. In the past we have always built with the understanding that as long as the conduits were not supported directly to the structure, it was not required. The use of trapeze or "J" hangers would adequately allow for any movement.

 

[benaround]

That's a good question.

 

[jusme123]

In the past we have always built with the understanding that as long as the conduits were not supported directly to the structure, it was not required.

what do you support the conduit to?

 

[kbsparky]

We worked at a large office building that had expansion joints in it, and had some conduit runs that had to cross them.

We would transition to a short section of flex across those building joints, and leave a slight sag in the flex. Conduits were securely fastened on both sides of the building expansion joint.

 

[Cavie]

It is usually up the the engineer/architect

 

[steve holt]

In the past we have always built with the understanding that as long as the conduits were not supported directly to the structure, it was not required.

what do you support the conduit to?

The conduit is supported either on unistrut or "J" hook which are supported by threaded rod.