Service Conductors Through Roof

When the service drop reaches the house it connects to an assembly called the service head also know as the service mast or masthead.

Service conductors through roof.

In general a building or structure can be served by only one service service drop or service lateral except as permitted by 203 2 a through d. The minimum clearance above only the overhanging portion of the roof shall not be less than 18 inches 457 mm where not more than 6 feet 1829 mm of overhead service conductor length passes over 4 feet 1219 mm or less of roof surface measured horizontally and such conductors are terminated at a through the roof raceway or approved support. If a set of 120 240v overhead service conductors terminate at a through the roof raceway or approved support with less than 6 feet of these conductors passing over the roof overhang the minimum clearance above the roof for these service conductors shall be. Application guidelines for service conductors everything you wanted to know about service conductors and more.

The service drop conductors are not to pass over more than four feet of a. The mast itself is on the side of the house but the service drop does not go to the mast from that side of the house. If the service mast is used in a through the roof application 120 208v or 120 240v conductor clearances can be reduced to 18 inches over the overhang portion of the roof 230 24 a ex 3. It goes over an open roof on a newer addition for about 12.

Additional services are permitted to supply fire. If the slope of the roof exceeds 4 inches for every 12 inches 120 208v or 120 240v conductor clearances can be reduced to 3 feet over the roof 230 24 a ex 2. The service drop is either anchored to a metal pole rising through the roof or attached to the exterior of the house. Of service drop conductors 1 2 m 4 ft horizontally pass above the roof overhang and 2 they are terminated at a through the roof raceway or approved support.

There are a couple of further stipulations for this exception to be allowed. Figure 230 10 230. The service drop attachment shall not be higher than 20feet above finished grade unless it is stipulated in the metering specifications. Service drop conductors pass over the roof of an intervening building clearance of three feet is required.

Typically a service head consists of a rigid steel conduit like a big pipe that runs up through the roof or along an exterior wall and is topped with a shell like fitting called a weatherhead or weather cap. If the voltage between conductors does not exceed 300v the conductor clearance over the roof overhang can be reduced from 8 ft to 1 5 ft if no more than 6 ft of overhead conductors pass over no more than 4 ft of roof overhang and the conductors terminate at a through the roof raceway or approved support. If the service mast is a through the roof installation meaning that it only penetrates the roof at the overhang to come down to a meter at the exterior wall below as in the photo above then the wires are only required to clear the roof by 18 inches.