Skip to main content

Difference between KW and KVA

 In this post, we will learn the difference between KW and KVA in electrical engineering.

Electrical power is a very important term which is commonly used in electrical circuits. When you are choosing or designing system, you first of all consider it’s power rating.


In electrical power, two of the most general purpose terms are – KW and KVA. KVA is usually heard in generators and transformers. But, it is also used in many other types of electrical devices.

Both these terms are power ratings used in every measuring the current characteristics. They are common electrical power abbreviations. In this post, we will see the difference between KW and KVA.


Difference between KW and KVA



  • KW stands for Kilowatts and KVA stands for Kilo Volts Ampere.
  • KW is the amount of power that is converted into a useful output. Therefore, KW is usually also known as actual power or working power. KVA is the measure of apparent power. Basically, it gives an indication of how much total input power is being provided into the system. So, you can say that KVA is the input power whereas kW is the output power. This is the first and foremost basic major difference between kW and KVA. If the system is perfectly designed or fully efficient (it is practically impossible), KVA will be equal to kW. This means the amount of power that you are feeding to the system is fully used by it at it’s output.
  • The basic formula of KVA is V x I; whereas the basic formula of kW is V x I x power factor. Power factor is usually also termed as waste power and is generally mentioned in a device nameplate.
  • KVA is naturally higher in ratings than kW.
  • kW ratings are normally shown in devices which use mechanical energy (for example a motor). KVA ratings are normally shown in devices which use electrical energy (for example a circuit breaker or transformer).  This is because, a circuit breaker is not driving any mechanical load; and if you see their ratings, they generally provide rated current. It means that the circuit breaker can allow this much of current to pass. This equals to KVA ratings (input power). Whereas, a motor is driving a mechanical load, and it will thus require actual power (useful power to drive the load). This equals to kW ratings (output power).  
  • You can convert kW to KVA or vice versa easily. For that, you need to know the power factor. The formula for converting kW to KVA is kW / power factor. The formula for converting KVA to kW is KVA x power factor.
  • If anyone asks the difference in one line, then you can say that KVA is the apparent power and kW is the real power in an electrical system.
  • They both are same in DC circuits, but are different in AC circuits.
  • Some common examples of kW rating devices are motors, lamps, home appliances etc. Some common examples of KVA rating devices are alternators, transformers, inverters, UPS etc.

These are the differences between kW and kVA. It must be up to the electrical engineer to decide what to choose, if he knows the basic requirements and functions.

Labels:

Comments

Post a Comment

Popular posts from this blog

PLC Program for Mixing Tank

 Create a ladder diagram for controlling a batch mixing process. Implement a PLC program for mixing tank or Mixing Process using PLC Ladder Logic. PLC Program for Mixing Tank Fig : Mixing tank A tank is used to mix two liquids. The required control circuit operates as follows: A. When the START button is pressed, solenoids A and B energize. This permits the two liquids to begin filling the tank. B. When the tank is filled, the float switch trips. This de-energizes solenoids A and B and starts the motor used to mix the liquids together. C. The motor is permitted to run for 1 minute. After 1 minute has elapsed, the motor turns off and solenoid C energizes to drain the tank. D. When the tank is empty, the float switch de- energizes solenoid C. E. A STOP button can be used to stop the process at any point. F. If the motor becomes overloaded, the action of the entire circuit will stop. G. Once the circuit has been energized, it will continue to operate until it is manually stopped. Solution...
1 comment
Read more

What is Relay? How it Works? Types, Applications, Testing

 We use relays for a wide range of applications such as home automation, cars and bikes (automobiles), industrial applications, DIY Projects, test and measurement equipment, and many more. But what is Relay? How a Relay Works? What are the Applications of Relays? Let us explore more about relays in this guide. What is a Relay? A Relay is a simple electromechanical switch. While we use normal switches to close or open a circuit manually, a Relay is also a switch that connects or disconnects two circuits. But instead of a manual operation, a relay uses an electrical signal to control an electromagnet, which in turn connects or disconnects another circuit. Relays can be of different types like electromechanical, solid state. Electromechanical relays are frequently used. Let us see the internal parts of this relay before knowing about it working. Although many different types of relay were present, their working is same. Every electromechanical relay consists of an consists of an Elect...
1 comment
Read more

Ferrules and Cross Ferruling

 Ferrules are identification labels provided for every wire terminations in an instrument, equipment, or electrical/instrumentation control panels. These tube-shaped sleeves can be inserted easily on each individual wire in a multi-core cable. In earlier days fixed digits/letters are used as ferrules, but now Instrumentation engineers/technicians prints out desired ferrules by using a ferrule printing machine. Typical Ferrule The numbers/ letters on the ferrules will be given as per the approved electrical hook up or loop diagrams. This helps technicians to easily identify a particular loop/wiring from a series of terminal blocks and to troubleshoot the desired terminal connection. Separate numbers on the ferrules distinguish the positive and negative polarities of wires, thus ensure the polarity protection of the instrument. Cross Ferruling  As a wire is connected on its both ends, it is quite useful to use a cross reference method for wire identification. Unlike normal ferru...
Post a Comment
Read more