Unsupported Drops

Question: Could virtually any electrical machinery or equipment be supplied from an exposed 20-foot vertical riser of rigid metal conduit or intermediate metal conduit where there is no intermediate supporting means readily available?

Answer: Exposed vertical risers are permitted from industrial machinery or fixed equipment ifif no means of intermediate support is readily available it is to supply fixed equipment, such as a machine tool or a checkout stand in a big box store. It is not the intent of NEC Sections 342.30(B)(3) and 344.30(B)(3) that moveable stands or equipment be connected in this manner.

The conduit must be supported at not more than 20 ft intervals and be securely fastened at the top and bottom and all couplings must be the threaded type.