Volt-Ampere (VA)

The term volt-ampere (VA) is a measurement of electrical power in a direct current circuit. It is also used in alternating circuit specifications. VA ratings in devices, such as computing equipment, is provided by the manufacturer. When choosing an uninterruptible power supply, the VA specifications of the network equipment, and of the UPS itself, must be reviewed. The UPS unit’s watt and VA rating should be compared to the total network load demands, keeping in mind that volt-amp and watt measurements are different. A range of UPS units with various watt and VA ratings are available to support consumer needs, SME power management, and data centre solutions.

VA Ratings for UPS Units

Knowing the VA rating for a UPS unit is key. This electrical rating specifies the amount of power protection provided. Power protection equipment for computer devices must be correctly sized. Manufacturers of UPS units usually report both maximum watt and VA ratings. Some models may only list a volt-ampere rating, because according to industry standards, the max watt rating is approximately 60 percent of the VA rating. The correct UPS device ensures a smooth flow of battery backup power for equipment operations or safe shutdowns during extended blackouts.

Maximum VA and UPS Size

When buying power protection devices, the maximum VA and UPS size must be considered. The manufacturer of each UPS model will provide a VA figure that is designed to prevent an overload of the uninterruptible power supply device. All of the equipment on a network contributes to an aggregate VA load. The UPS should have a VA rating which is twice this load measurement. A new UPS size or type may be required if equipment loads reach more than 60 percent of the specified max VA for a UPS device. Comms Express can assist buyers in determining the right UPS for their runtime demands.