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(5) Appliances without any indication as to power consumption
Some appliances have no indication as to power consumption; but instead the work load (output) is
indicated. In such a case, power consumption is to be worked out according to the numerical formula
mentioned below.
Efficiencies of some electrical appliances are as follows :
Single-phase motor . . . . . .0.6 to 0.75 (The smaller the motor, the lower the efficiency)
Fluorescent lamp . . . . . . . .0.7 to 0.8
Example 1: A 40W fluorescent lamp means that its luminous output is 40W. Its efficiency is 0.7 and
accordingly, power consumption will be 40 0.7= 57W. As explained in Item (2), multiply this
power consumption value of 57W by 1.2 to 2 and you will get the figure of the necessary
capacity of a generator. In other words, a generator with a rated output of 1000W capacity
can light nine to fourteen 40W fluorescent lamps.
Example 2
: Generally speaking, a 400W motor means that its work load is 400W. Efficiency of this motor
is 0.7 and power consumption will be 400 0.7= 570W. When this motor is used for a
motor-driven tool, the capacity of the generator should be multipled by 1.2 to 3 and 570W as
explained in the ltem (3).
The power consumption of electrical appliances is shown below for reference, use this as a measuring
guide when choosing electrical appliances and which generator to use.
