part of a municipality. The area contains land use
Association of Edison Illuminating Companies.
which attracts a relatively heavy volume of night-
time vehicular and/or pedestrian traffic on a fre-
American National Standards Institute.
Conventional energy system
A conventional energy system supplies electric
Insulated Cable Engineers Association.
energy which is not generated by the user and
over which the user normally has only local
control. Conventional energy systems are provided
Institute of Electrical and Electronic Engineers.
and supplied by a utility unless that electric
source has been clearly demonstrated to be inade-
quate or unreliable, or another energy source has
Illuminating Engineering Society.
been proven to be more economical.
Dead front (as applied to switches, circuit
National Electrical Code (NFPA-70).
breakers, switchboards, and distribution panel-
National Electrical Manufacturers Association.
So designed, constructed, and installed that not
current-carrying parts are normally exposed on the
National Electrical Safety Code (ANSI C2).
Dead front (as applied to transformers)
So constructed that there are not exposed live
parts on the front of the assembly.
Angle of deviation (pole line)
The angle by which a pole line deviates from a
The electrical load at the receiving terminals
averaged over a specified interval of time. Demand
is expressed in kilowatts, kilovolt-amperes, am-
Basic impulse insulation level (BIL)
peres, or other suitable units. The interval of time
A reference impulse insulation strength expressed
is generally 15 minutes, 30 minutes, or one hour.
in terms of the crest value of withstand voltage of
a standard full impulse voltage wave.
The radio of the maximum demand of a system to
the total connected load of the system.
Any demand that occurs simultaneously with any
other demand, also the sum of any set of coinci-
Demand factor-(Max. demand)/(Total con-
nected load) Discharge current
The surge current that flows through an arrestor
when sparkover occurs.
The distributor and collector roadways servicing
traffic between major and local roadways These
are roadways used mainly for traffic movements
The voltage that appears across the terminals of
within residential, commercial, and industrial ar-
an arrester furring passage of discharge current.
A business area of a municipality where ordinarily
from a primary distribution circuit to a secondary
there are many pedestrians during night hours.
distribution circuit or consumer's service circuit.
This definition applies to densely developed busi-
ness areas outside, as well as within, the central
order of 5-500 kVA.