(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
UP
mentioned below.
(Output of electrical appliance)
(Efficiency)
=
(Power consumpition)
Efficiencies of some electrical appliances are
as
follows
:
Single-phase motor
................................
0.6
to
0.75
The smaller the motor, the
Three-phase motor
................................
0.65
to
0.9
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
f
0.7=
57W.
As
explained in Item
(2),
multiply
this power consumption value of
57
W
by
1.2
to
2
and you will get the figure of the neces-
sary capacity
of
a
generator.
In
other
words,
a generator
with
a rated
output
of
1
OOOWcapacity
can
light nine to fourteen
40
W
fluorescent lamps.
Example
2
:
Generally speaking, a
400
W
motor means that its work load is
400
W.
Efficiency of this
motor is
0.7
and power consumption
will
be
400+0.7=
570
W. When this motor is used for
a motor-driven tool, the capacity of the generator should be multiple of
570
W
by
1.2
to
3
as
explained
in
the Item
(3).
570
(W)
x
1.2
to
3
=
684
(W)
to
171
0
(W)
MODEL
RGD5000
Frequency
60
Hz
lncandesent lamp,
heater,
etc.
4500
w
Fluorescent lamp,
Motor-
driven
tool,
general-porpose
I
approx.
3000
W
I
Mercury lamp,
etc.
approx.
2700
W
I
I
Pump,
compressor,
etc.
Table.
7-1
-
16-
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