An Uninterruptible Power Supply, or UPS, is a device that provide emergency power to electronic equipment if the power source should fail. To determine the correct UPS to purchase, one must understand that a UPS provides a specific amount of runtime for an electronic equipment. The amount of runtime that a UPS can provide depends on the load of the electronic equipment that the UPS must supply with power.
Many people believes that the UPS with the highest Volt-Ampere (VA) rating will run for the longest amount of time. However, the higher the load on a UPS, the less amount of runtime the UPS will have. To ensure that the UPS can provide enough time for the electronic equipment to operate until the emergency power supply, one must calculate the number of Watts that the electronic equipment use.
How to Choose the Right UPS
In understanding the specifications of a UPS, one must become familiar with the difference between the Volt-Ampere (VA) and Wattage rating of the UPS. The VA rating of a UPS is the apparent power of the UPS, while the Watts of a UPS is the amount of real power that is supplied to the electronic equipment. To determine the Watts of a UPS, one must multiply the VA of the UPS by the factor of the power of the UPS.
For example, if a UPS has a VA of 1500 and a factor of the power of 0.6, the multiplication of these two value will equal 900 Watts. If the Watts of the electronic equipment is higher than the Watts of the UPS, the UPS will overload and fail. There are different type of topologies within UPS models.
One must choose the topology of a UPS that is purchased according to the sensitivity of the electronic equipment to the power supplied by the UPS. Standby UPS model are the most basic models. They will only provide power to the electronic equipment if the primary power supply fail.
Standby UPS models are good for desktop computers but not for critical servers. Line-interactive UPS models are more involve with the power supplied to the electronic equipment. With line-interactive models, the UPS can stabilize the voltage supplied to the electronic equipment without use the battery.
This model will allow the electronic equipment to experience brownout but will not drain the battery of the UPS. The most advanced model is the double-conversion UPS. With this model, the UPS converts the power from alternating current to direct current and then to alternating current again.
This model will provide the cleaner power to the electronic equipment but will cost more money than other models. Within a UPS, the batteries are the components that will provide emergency power to the electronic equipment. The batteries have a limited lifespan.
Most manufacturers use sealed lead-acid batteries in their UPS units. These types of batteries will last between three and five year. One must keep the UPS in a cool environment.
High temperature will shorten the lifespan of the batteries within the UPS. Another option is to use a lithium battery. Lithium batteries will last longer and weigh less than sealed lead-acid batteries.
The downside of using lithium batteries is that they cost more money. The batteries within a UPS will fail at some point. To avoid not being able to supply power to the electronic equipment during a power outage, one must replace the batteries within the UPS before they fail.
To install a UPS in an office, data center, or other location with electronic equipment, an organization should take a few steps. First, the organization should calculate the total number of Watts that is consumed by the electronic equipment. The total Wattage can be calculated by using a power meter or simply by reading the labels that is on the electronic equipment.
Second, add twenty percent to the total number of Watts. This will ensure that the UPS is not running at maximum capacity. Using less than half of the total capacity of the UPS will allow the UPS to provide emergency power for longer periods and will extend the lifespan of the batteries.
Finally, use the UPS management software to monitor the UPS. Using management software will allow the administrator to monitor the status of the batteries of the UPS. If the batteries is low on power, the software will allow the administrator to gracefully shut down the electronic equipment.