I need to know what will be happen went 240V drop to 200V.. What will happen
-amps (will it decreasing?)
-kilowatt (will it decreasing?)
-appliance (any effects?)
why this is happen?
pls reply to me as soon as possible.. i need to know.!!
Depends on the load and, to an extent, whether it is a dc or
For a purely fixed-value resistive load, the amps and
kilowatts will decrease and the load will just not give out
as much heat. This is a little more complicated than that
with loads which have resistances that change with the
current flowing throught them - eg lamps. They typically
will take more current and hence more kilowatts than simple
Ohms Law would predict.
For an appliance which compensates for supply voltage, eg
with a switched mode power supply capable of taking this
range of supply, the amps will increase, the kilowatts will
remain much the same and the load will show no obvious
For an appliance not designed to take this range of supply,
eg containing certain types of motor or power supplies that
are not designed for this range - the amps will typically go
up and then up and then up. The kilowatts will go up and
then up and then up. The smoke will then go up and then up
and then up.
Why does these things happen?
A purely fixed value resistive load simply obeys Ohms Law,
so as the voltage drops, the current drops and so does the
A resistive load with a resistance that varies with amps
obeys Ohms Law, but using the value of resistance that will
be present for that much current flowing. The kilowatts will
decrease with decreasing supply voltage - but not by as much
as might be expected by simply considering the power taken
on full voltage.
A compensating load, eg a switched mode power supply, has
feedback built in - so that it automatically increases the
average current if the average voltage falls. The kilowatts
thus roughtly remain constant.
A load operated outside its designed range may try to
compensate but may not be able to handle the continuous
extra current that is needed or may simply go into a non
safe area of operation for which it wasn't designed. Under
these conditions, either something overheats and dies -
producing smoke, flames etc, or efficiency drops greatly,
leading to overheating, smoke and flames.
So, if you want to be more specific on what you are
interested in as a load, do write again.