If you’ve ever shopped for a generator, you’ve probably seen the term kVA listed in the specifications. We’re used to seeing power ratings expressed in watts, kilowatts, amperes, amps or volts, but not generally in kVA.
So what does kVA actually mean? kVA stands for kilovolt-ampere, which is used to measure the Apparent Power of an electrical system such as a generator or transformer.
And for the next question…what is ‘Apparent Power’?
Apparent Power is the total power available, rather than what is actually being used. It’s a measure of potential power and is crucial to match power needs to the right generator and to avoid overloading.
volts x amps x 1000 = kilo volt-amperes (kVA)
- Kilo = 1,000.
- Volt = the pressure that pushes the electric current.
- Ampere (amp) = the flow of electric current.
Understanding kVA can help you choose the right generator for your home or business and avoid power problems when you most need it.
What Does kVA Mean on a Generator
A generator is one item where kVA is used as a measure of power. Essentially, the higher the kVA rating, the more power the generator produces. Kilovolt-amps (kVA) measure the Apparent Power of a generator, while kilowatts (kW) measure the Actual Power. The difference between the two is the Power Factor (PF).
To explain further we’ll break it down into three factors: Apparent Power, Actual Power and the Power Factor.
Apparent Power (kVA) describes the total amount of power being used by a system.
Actual Power (kW) is the amount of power that is converted into an output.
Power Factor (PF) is the ratio of kW to kVA.
Why Are Generators Rates in kVA?
Manufacturers use kVA ratings because it applies to all types of loads, avoiding assumptions about efficiency, which varies by application. Measuring power in this way means the generator can meet the total electrical demand.
When we talk about apparent power, we mean the total power supplied by a generator – both the usable power that runs devices and the amount of power lost through inefficiency.
The Difference Between kVA and kW
In the world of electrics, we’ve all heard of kilowatt (kW). Kilowatt is displayed on most electrical product specifications, and it’s how energy companies measure the amount of electricity we’ve used. In the context of electrical items, it indicates how much power an appliance consumes or how much power an electrical device can deliver.
Top Tip: Size-up your generator purchase for planned extensions, electric vehicles or extra critical appliances.
How to Choose the Right kVA Generator
Getting the right generator to match your power needs is essential to ensure you have sufficient back up power when you need it, and to avoid unnecessary costs from purchasing a generator that is too big. The process for calculating how much power you need during a power cut, or if you’re off grid is easy.
Just add up all of the items you want to power. Let’s take a more detailed look.
- List the appliances and equipment you need to run during a power outage – take note of the start up wattage and the running wattage as many appliances require extra power during start up.
- Add up the total wattage (kW).
- Adjust for the power factor – typically 0.8 for most generators.
- Convert to kVA using the formula above.
- Add a safety margin – choose a generator with around 20% more capacity than you need to account for increased power requirements in the future.
- Match to your ideal generator.
Read ‘Best Backup Generator for Your Home’, ‘What Size Diesel Generator Do I Need?’ and ‘What Size Generator Do I Need for Outdoor Events’ for extra guidance.
Understanding kVA is essential for making smart generator choices. By knowing the difference between kVA and kW you can avoid costly mistakes and power downtime when you most need it. For more information on choosing the right generator contact Vital Power.
Anna Eyre
Digital Marketing Lead
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