Electrical Energy Basics
Electric current is divided into two types:
Directional Current (DC)
Alternating Current (AC).
Kilovolt Ampere (kVA)
Single phase electrical circuit ,
Apparent power (kVA) = Voltage x Amperes/1000
Three phase electrical circuit ,
Apparent power (kVA) =1.732 x Voltage x
kVAr is the reactive power. Reactive power is
the portion of apparent power that does no
work. This type of power must be supplied to
all types of magnetic equipment, such as
motors, trans- formers etc. Larger the
magnetizing requirement, larger the kVAr.
Kilowatt-hour is the energy consumed by 1000
Watts in one hour. If 1kW (1000 watts) of a
electrical equipment is operated for 1 hour, it
would consume 1 kWh of energy (1 unit of
Three phase AC powermeasurement
Most of the motive drives such as pumps,
compressors, machines etc. operate with 3
phase AC Induction motor. Power
consumption can be determined by using the
Power= 1.732 x V x I x CosF
Single phase AC powermeasurement
A watt meter Measures
power consumed by an
apparatus in a given time.
Normally watt meter gives
reading in watt or kilowatt.
A Wattmeter have two
coils one is current coil
and other is voltage coil.
The power is product of
Voltage across the load
and current flowing
through the load i.e.