Chapter 10 The Service Entrance
175
Copyright Goodheart-Willcox Co., Inc.
Service Disconnects
Section 230.71(A) of the NEC requires that
disconnect means or service entrance conduc-
tors cannot exceed six switches either in a single
enclosure or a group of separate enclosures.
Several permissible arrangements are shown in
Figure 10-19.
Main Disconnect and
Service Panel
There must be equipment that will discon-
nect all wiring from the power source. This can
be arranged by using a single main disconnect
switch or a main circuit breaker that is part of
the service panel. See Figure 10-20. Regardless
of the method used, the disconnect must be
located in an accessible place. Further, it must
be located as close as possible to the point where
the service conductors enter the structure.
Service Grounding
Grounding the service entrance is vital to
the safety of the entire electrical system. Careful
attention should be given to this section to
ensure a thorough understanding of the proce-
dures involved. In addition, you should study
all sections of Article 250 of the NEC before
undertaking any electrical installation.
Grounding the service entrance involves
connecting the neutral or white service conductor
with the earth. This is done by means of the
grounding conductor. This conductor connects
the neutral lug of the meter housing or the neutral
bus bar of the service switch (service panel) to the
metallic water supply pipe. See Figure 10-21.
GFCI power distribution box GFCI adapter
Figure 10-18. Use GFCI equipment to protect yourself and other workers. (Coleman Cable, Inc.)
Figure 10-19. Permissible service disconnects.