- Q.The proposed location for
my client's new detached garage is right on top of a
buried service-entrance cable. The electric meter is
mounted on a pedestal about 100 feet from the house,
and a conduit runs to the house through the area where
the garage — which will have a stem-wall
foundation and concrete slab floor — is to be
located. The electric utility doesn't have a problem
with the building's location because it is responsible
for the line only as far as the meter. Is it okay to
pour the foundation around the conduit so that it runs
through the stem walls and underneath the new slab, or
do the cable and conduit have to be rerouted around the
foundation?
A.Joe Tedesco, a licensed
electrician, a certified electrical inspector, and
the moderator of JLC Online's electrical forum,
responds: In general, the NEC doesn't permit
service-entrance conductors to pass through the
interior of another building unless they are
protected by brick or concrete, or a specially
constructed vault.
But in your case, as long as the conductors are
enclosed in conduit and are buried at least 18
inches below grade, the NEC would consider them to
be outside the building (2005 NEC 230.6[4]).
In addition, the NEC considers these conductors
to be outside of a building when covered by a
concrete slab that measures at least 2 inches
thick. So your existing service entrance is fine
where it is, though it will make excavating the
site and pouring the foundation a little
trickier.