HANDBOOK REQUIREMENTS - Central Maine Power Company

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VII. GROUNDING
AND BONDING
700. GENERAL
Service entrance grounding must be in compliance with the
NEC a nd all applicable municipal and State requirements. NEC
Sectio n 250.4 covers the “General Requirements for Grounding
and Bonding.”
A grounded electrical system shall have its neutral
conne cted to earth in a manner that will limit voltage imposed by
lightning
or line surges; as well as, stabilize the voltage during
normal
operation. Electrical enclosures and other electrically
conductive
material likely to become energized shall be installed
in a manner
that creates an effective ground-fault current path;
as defined
in NEC 250.2, "an intentionally constructed,
permanent,
low-impedance electrically conductive path designed
and intended to carry current, under ground-fault
conditions, from
the point of a ground fault on a wiring system to the electrical
supply source . . ."
In accordance with NEC Section 250.24, any grounded ac
system operating at less than 1,000 volts, shall have the grounded
condu ctor (neutral) run to each service disconnecting means and
bonded
to each disconnecting means enclosure or assembly.
Additionally,
the neutral (for a grounded system) and service
equipment enclosures
(for a grounded or ungrounded system)
shall be
bonded together and connected by a grounding electrode
conductor
to the grounding electrode system. Connection of the
grounding
electrode conductor to the service neutral may be made
at any accessible
point from the load end of the service drop or
service lateral to, and including, the neutral terminal or bus at the
service
disconnecting means. This connection is normally
made
to the service entrance panel neutral bus or meter enclosure
neutral/ground
lug, whichever will result in the shortest grounding
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