What's Wrong Here?

Sep 27, 2007 5:11 PM, By Joe Tedesco, NEC Columnist

Hint: Pull the plug!

”These photographs show the most unusual interpretation of NEC Sec. 230.53, Raceways to Drain," says Bob Froehlich of Jackson, N.J. “This is an 800A underground electrical service running from an exterior utility pole to a below-grade ‘basement’ utility C/T cabinet. Take note of the 1¼-inch RMC conduit exiting the C/T cabinet and running along the floor to a sump pump drain. In addition, note the two saddle straps on the incoming electric RMC conduits. They feature bored holes through the sidewalls for drainage. The two 1½-inch drain pipes exit to another drain pit.” As per 230.53, “Where exposed to the weather, raceways enclosing service-entrance conductors shall be raintight and arranged to drain. Where embedded in masonry, raceways shall be arranged to drain. Exception: As permitted in 348.12(1).”

Section 225.22 requires raceways installed on exterior surfaces of buildings or other structures to be arranged so as to drain. They must also be raintight in wet locations. This requirement applies to outside branch circuits and feeders. An exception to this rule states, “Flexible metal conduit, where permitted in 348.12(1), shall not be required to be raintight.” In addition, 348.12 states FMC shall not be used in wet locations unless the conductors are approved for the specific conditions, and the installation is such that liquid is not likely to enter raceways or enclosures to which the conduit is connected. A wet location is defined as an installation: under ground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.

Raintight is defined as: constructed or protected so that exposure to a beating rain will not result in the entrance of water under specified test conditions.