Tuesday, August 29, 2017

KVA vs KW - KVA and KW - Difference between KVA and KW


Have you ever noticed that with every appliance or piece of electrical machinery that you avail, they will always indicate their respective power ratings?


You will notice that some electrical equipment express their power ratings in kilowatts; and some are expressed in KVA, kilo Volt Amperes. Both values express power, but they are actually different.



Video Source By- Learning Engineering

KVA is known as the ‘apparent power’ of a particular circuit or electrical system. In direct current circuits, KVA is equal to Kilowatt, because voltage and current do not get out of phase. However, ‘apparent power’ and ‘real power’ (which is expressed as  Kilowatt) may differ in alternating current circuits. Kilowatt is simply the amount of actual power that does valid work. It should be noted that only fraction of KVA is accessible to do work, and the rest is an excess in the current.


KVA vs. KW

● KVA is known as the ‘apparent power’, while Kilowatt refers to the actual, or real power.
● Kilowatt is the amount of power capable of doing work, while only a portion of KVA is available to do work.
● Kilowatt is kilowatts, while KVA is kilo Volts Amperes.
● KVA is equal to Kilowatt in DC circuits because the voltage and current are not out of phase (unity).
● However, in AC circuits, voltage and current may get out of phase. Therefore, Kilowatt and KVA will differ depending on the Power Factor, or how much leading or lagging occurs.