When comparing various power ratings, you might notice that some of them are expressed in KVA or KW, others in Amps, and others in Volts. Here we explain what the difference is and we answer a number of questions related to phases in electricity.

KVA	KVA is 1,000 volt amps
Volt	a Volt refers to electrical pressure
Amp	an Amp is electrical current
Kw	Kw stands for kilowatt and is a measure of power (one Kw is 1000 watts)

What is a phase in electricity?

In electricity, the phase is used to describe the distribution of load. In simple terms, if one wire is used, all the load is on it. If three wires are used, the load is divided between them so there is less load on each.

But what exactly is the difference between single-phase and three-phase power supplies?

Single-phase supply uses a power circuit with two alternating wires. Usually, there is one power wire, also known as the phase wire, and one wire known as neutral wire. There is current flowing through the load between the power wire and the neutral wire.

Three-phase power supply, on the other hand, uses a power circuit with three alternating wires. Each of them is 120 electrical degrees apart.

Single-phase vs three-phase power supply

In residential properties, one can typically find the single-phase power supply, while commercial and industrial facilities tend to use the three-phase one. This is because the three-phase power supply performs better when it comes to accommodating higher loads. Single-phase power supply is normally used for not so energy-intensive activities such as lighting or heating.

Another difference between the single-phase power and three-phase power is the consistency of the delivery of power. When it comes to the single-phase power, there are frequent dips in voltage, which means that it does not offer the consistency that the three-phase power, which delivers power at a steady rate, offers.

Overall, three-phase power supplies are more efficient as they are capable of transmitting three times more power than a single-phase power supply. In addition to that, three-phase power supplies use less conductor material to transmit the same amount of power as single-phase power supplies.

Calculating Amps and KVA in single and three phase loads

If you want to calculate amps and KVA in single and three phase loads, you need to use the following formulas:

Single phase Amps = (kVA x 1000)/Volts
Three phase Amps = (kVA x 1000)/Volts x 1.73
Single phase KVA = (Volts x Amps)/1000

Three phase KVA = (Volts x Amps x 1.73)/1000.

What is reactive power and real power?

In AC power systems, there are two kinds of power – real power that works and reactive (imaginary, non-real) power that enables transformers, generators, and motors to perform their roles.

Reactive power is the power that moves back and forth between source and load in the circuit. It is denoted by ‘Q’ and is measured in VAR, which stands for Volt Ampere Reactive, kVAR or MVARs. This type of power is also called non-real power and it refers to storage and retrieval of energy rather than consumption. Reactive power plays an important role in producing magnetic and electric fields in AC circuits.

Real power is expressed in watts and it refers to the actual energy that has been converted from electrical energy and consumed. So, real power is used in the circuit while reactive power bounces back and forth between the load and the source (which some can say is useless).

What are harmonics in power systems?

As explained by EATON, ‘harmonics are distorted electrical waveforms that introduce inefficiencies into your electrical system. They produce wasteful heat and can cause plant issues and fees from your local power company.

Harmonic frequencies flow into the electrical system as a result of nonlinear electronic switching devices, such as variable frequency drives (VFDs), computer power supplies and energy-efficient lighting.’

The main harmonic sources are:

VFD’s
EC motors
battery chargers
EV chargers

Computer power supplies
LED lighting
Fluorescent lighting
Other electronics.

Harmonics can cause a number of problems such as increased electrical usage, more wear on equipment, higher maintenance costs, penalties for causing problems to the power grid.

KW calculator

If you need to convert amps to kilowatts, you can do so using our KW Calculator.

We came up with the idea for the Kw Calculator because we know that memorising formulas needed to do it without using technology can be difficult. Moreover, we understand that not everyone is an energy expert and understands all the different terms and abbreviations associated with power supplies.

To convert amps to kilowatts the regular way, you would have to use this pattern:

kilowatts = (amps x volts)/1,000

Sounds complicated? You are right, not only do you need to know what all of these mean and how to check them, but you also have to have serious Maths skills.

Luckily, if you use our calculator, you can get the result with practically no effort and no thinking.

How does the KW calculator work?

Okay, so you might be thinking that the calculator sounds like a great device but you are not sure how to use it.

Using our KW calculator is very easy. Here is a step by step guide to help you get started:

Choose current type (AC single phase or AC three phase)

Enter current (in amps)

Enter voltage (in volts)

Click ‘calculate’

After you finish these steps, you will receive a result in kilowatts! You do not have to make any calculations on your own.

Why you should use our calculator

The main benefit of using our calculator is that it makes converting amps to kilowatts as straightforward as it can possibly be. Anyone can use our device, no matter how little knowledge of power supplies they have. All you need to do is enter a few numbers and our calculator does all the work for you. Thanks to that, you can save effort and time.

You might be asking yourself why you should use our calculator rather than a different one available online.

At Energy Solutions, we have more than 20 years of experience operating in the energy industry and we are committed to making things easier for our clients. We based our KW calculator on the standard formula used to convert amps to kilowatts so you can be sure that the result you are getting is accurate.

We have other calculators too

We have also previously developed a number of other calculators:

One allows clients to calculate their electricity bill online – they can do so immediately without having to enter any personal information. Our calculator helps them understand their charges and determine whether they are paying the right rates
One allows clients to calculate their gas bill online – thanks to our device they can ensure that their supplier is not overcharging them for their gas supply
One allows clients to calculate their water bill – at Energy Solutions, we also work with water suppliers and we want to help clients understand how their energy bill works. Thanks to our device, they can find out what elements make up their water bill and how they are calculated.

If you need assistance with checking any of these things, click the links and try out our calculators! Or, if you have any questions, reach out to us. You can give us a call on 0131 610 1688 or send us an email to nick@energybrokers.co.uk. We are always happy to hear from our existing and prospective clients.