and electric devices and horsepower of

required to serve a given connected

all motors.

The load is usually

load.

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

of lighting load or 1 horsepower of

types of structures.

Naturally the

motor or power load equal 1 KVA.

A

demand load may never be greater than

second

method

of

estimating

the

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

foot

for

a

particular

type

of

times or because the peak loads of

building.

Such standard loads may be

these various pieces do not occur

found

in

appropriate

TM's.

simultaneously.

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

requirements

of

connected

lights,

is 1.00.

However, a machine shop

appliances, or motors in a given

whose maximum demand may have been

building

(analogous

to

counting

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.

In all

Twenty 100-watt lamps------------2.0 KW

of these estimations, the connected

load

should

be

determined

per

Motors, connected, 30 hp--------30.0 KW

building.

To expedite the estimating

of connected loads to the various

Heaters--------------------------9.0 KW

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