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.
(Output of electrical appliance)
(Efficiency)
= (power consumption)
Efficiencies of some electrical appliances are as follows:
Single-phase motor . . . . . . . . . . 0.6 - 0.75
Three-phase motor . . . . . . . . . . 0.65 - 0.9
Fluorescent lamp . . . . . . . . . . . 0.7 - 0.8
The smaller the capacity, the worse the efficiency,
and vice versa.
Example 1: A 40 W fluorescent lamp means that its luminous output is 40 W. Its efficiency is 0.7 and accordingly,
power consumption will be 40 i
0.7
= 57 W. As explained in Item 2, multiply this power consumption
value of 57 W by 1.2 - 2 and you will get the figure of the necessary capacity of a generator. In other
words, a generator with a rated output of 1000 W capacity can light 9 - 14 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 capa-
city of the generator should be multipled by 1.2 to 3 and 570 W as explained in the item 3. Moreover,
in case when used this motor for the pump in the water or cornpresser, it is necessary 3 - 5 rimes powerful
generator according to the item 4.
Model
I
RGX305
I
RGX405
RGX505
RGX305D
RGX405D
RGX505D
Frequency : 5OHz
60Ht
5OHZ
6OHZ
’ 5OHz
60Hz
incandescent lamp,
hot plate, etc.
1
2500w
2900w
3300w
3700w
j 4400W 4800W
Fluorescent lamp,
about about ) about
about
! about
mercury lamp, etc.
16OOW
) about
! 19OOw
2200w
/ 2500W 2900W I 3200W
I
Motor-driven tool, ’
general-purpose
about about I about
i about
I
about
motor, etc.
! 15oow
17OOw
I 2ooow ,
2200w j 2%%
I I
2800w
Water pump,
compressor
1 about 1 about
!
i about
750W j 850W ( 1OOOW
about
I
I
about about
I
11oow ( 125ow 1 1400w
Table 7- 1
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