WHAT IS POWER FACTOR OR PF – WHAT DOES kVA MEAN – WHY ARE kW DIFFERENT TO kVA – WITH WORKED EXAMPLES

welcome to another video from learn electrics in this video we'll take a very gentle look at Power Factor watts and volt amperes starting at a nice easy level we look at what the different terms mean and how they work together in an electrical installation there are always lots of questions about power factor and some of them have

included things like how can I calculate power factor and Watts in fact what is power factor and how does it affect the installation and why are VA and Watts different I always thought the V times a was Watts and now it isn't before we start working out VA and power factor let's have a look at some Basics

that will help in a purely resistive circuit the current and voltage are exactly in Phase with each other as the voltage crosses the zero line so does the current the amps as the voltage Peaks so does the current they are synchronous with each other this means that the maximum amount of power is delivered into the circuit

but in a circuit with reactants as shown in the bottom graph the voltage and current are not in Phase certain components in the circuit will create a reactance either inductive or capacitive Motors welders generators fluorescent lighting Transformers and so on these reactances make for inefficiencies in the system and cause losses in the

circuits this means that not all the power being put into the system from the supply is being turned into useful energy or work at the point of use and somebody is paying for that this is why Zs for example is an impedance and not a resistance it's a live test on an AC

circuit that has reactive equipment in the circuits everybody knows about the power triangle power equals voltage times current and it can be written as watts equals volts times amps or W equals VA but not in this video here what do not equal volts times amps we are considering circus with reactants systems with Transformers Motors coils