The Volt-Ampere (VA) is a unit of measurement for power that a device uses in terms of voltage (V) and amps (A). Consider water running in a pipe: Voltage is to water pressure, as current is to the flow of water. Together, VA determines the total power consumption of a device. This is the amount of power it takes to illuminate the lamp, and the amount of power used to electrify the circuit (wasted power). Ideally the lower the VA rating the more efficient the circuit. With a lower VA rating, your system can use a smaller transformer to drive the same number of more efficient lights on a circuit.
Volt-Ampere in Depth:
The Volt Ampere (VA) system is a method of measuring the power consumption of electrical components, such as LED lights among other devices. It’s important to have a basic understanding of this system when choosing and installing LED lighting, as it can affect the overall energy efficiency and performance of the lighting installation.
VA can be identified in two ways,
- By using the formula V x I = VA where Voltage (V) x Current (I) equals Volt-Amperes.
- If you know what the power factor of the lamp is, it can also be determined by W/PF = VA where you take the wattage of the bulb and divide by the Power Factor (PF) to get the Volt-Ampere.
The VA system measures the power consumption of a device in terms of voltage (V) and current (A). Think of voltage as the electrical pressure that pushes the current through the device, while the current is the flow of electrical energy. Together, they determine the total power consumption of a device.
A multimeter is a device used to measure electric current, voltage, and usually resistance, typically over several ranges of value.
Using VA System to Identify LED Light Power Consumption
In both cases below, the power consumption is 6VA, but the current differs. It is important to note that the power consumption of LED lights is not always the same as their power rating.
- 6W LED light with 12V:
- Current: 0.5A
- Power consumption: 6VA
- 6W LED light with 24V:
- Current: 0.25A
- Power consumption: 6VA
This is because LED lights are often operated at a lower voltage than traditional incandescent lights, which can lower their total power consumption. Additionally, the VA rating of LED lights can vary depending on the type of driver and dimming system used.
When choosing LED lighting, it is important to consider the power consumption of the lights in terms of VA. This will help ensure that the lights are energy efficient and operate at an optimal performance level. Not all LED bulbs are created equal, some bulb drivers use more energy than others outside of the required amount to produce light. This is why it is also important to choose LED lights with high-quality drivers and dimming systems to further increase their efficiency. In general, the lower the VA rating of the lamp the better, as there is less wasted energy in the circuit dedicated to producing light.
This knowledge will allow for a better understanding of the type of transformer needed for any given number of bulbs on a circuit and give you a solid idea of what you can expect if you decide to add more lamps to a circuit or at a later time.
V x I = VA
W/PF = VA
In Summary:
The Volt Ampere (VA) system is an important method of measuring the power consumption of electrical devices, and in our case, LED lights. Understanding the VA system and how it relates to LED lighting can help ensure that you choose and install lights that are energy efficient and operate at their optimal performance level.
If you have any questions or would like us to help you make a choice based on your needs, please feel free to reach out to your local Central Turf & Irrigation Supply Landscape Lighting Expert. We are happy to help!