required to serve a given connected
The load is usually
The demand factor is the ratio
expressed in KVA (kilo-volt-amperes).
between the estimated maximum demand
For purposes of estimation, 1000 watts
and the connected load for various
types of structures.
motor or power load equal 1 KVA.
demand load may never be greater than
the total connected load, and is
connected load is by use of a standard
usually less because different pieces
load expressed in watts per square
of apparatus are used at different
times or because the peak loads of
Such standard loads may be
these various pieces do not occur
An exception occurs
Multiplying the floor area of a given
when all of the using pieces are of
type of building by its standard load
the same type and used at the same
will give the connected load for the
time to full capacity, as in street
building. Finally, the connected load
lighting circuits and yard lighting.
may be determined by summing the power
The demand factor for this exception
However, a machine shop
appliances, or motors in a given
whose maximum demand may have been
measured to be 31.4 KW could have a
outlets and showers in water supply).
total connected load of:
This may be done either from drawings
of the individual buildings or from
Thirty 60-watt lamps-------------1.8 KW
visual inspection of the apparatus in
the buildings to be serviced.
Twenty 100-watt lamps------------2.0 KW
of these estimations, the connected
Motors, connected, 30 hp--------30.0 KW
To expedite the estimating
of connected loads to the various
types of buildings considered in this
course, table 1 will be used for
Welding equipment---------------20.0 KW
obtaining the lighting and power loads
to each building.
This table also
Total connected load---------62.8 KW
gives the type of power required,
single phase or three phase, and the
wiring. The values given are in KVA.
(1) Demand load. The demand load
is the actual maximum demand in KVA