news / tech talk

UPS usage in modern business.

by Lee LeClair
As seen in Inside Tucson Business

For many businesses, the need for reliable power has become critical just as the supply has become less certain. In many cases, computers systems that are always up have become mandatory for our 24x7 world. In the meantime, 9/11 and several power crisis ranging from California to the northeast have reminded us that reliable power is not a given. Occasions always arise that can cut the supply lines to our critical resources, sometimes for hours. Power issues can also include surges, sags, spikes, and noise. A typical accident with a power line causes a damage-inducing surge and then a total loss of power for an area.

The businesses that can afford it house their critical systems in data centers. Data centers are typically devoted to providing reliable infrastructure by providing high capacity uninterruptible power supplies (UPS), power conditioners, power generators, connectivity to multiple power substations, high capacity air conditioning, and fire control systems. For everyone else, there are some other options.

A good strategy involves first taking stock of your systems: which are critical? Which could be consolidated? Are they in the same room? Are they on the same circuit? Are they old? How are they cooled? Once you have identified which systems must not go down, calculate how much power they require. You can do this by checking their power consumption which is usually provided in volt amperes (VA) or watts. If the rating is watts, multiply that number by 1.4 for VA. Add them up and you will have a rough amount you can use as a requirement for UPS or other needs. Remember to leave some capacity for growth (additional systems) and remember that if you include a monitor, includes its power requirement too.

Regarding UPS, there are two main types available: standby power supply type and continuous power inverter types. Standby power supply type UPS work by routing power directly from the line to your equipment, their battery power only comes into effect after a power loss with a battery-powered inverter to detect power loss and switching to the battery. This type of UPS has an inherent delay before it comes online because it must detect a loss of power first then switch. This type of UPS is more inexpensive and typically good enough for workstations but not servers. The continuous power inverter type UPS take line power and constantly passes it through an inverter to your equipment. There is no switchover since it is always on. This type of UPS is more expensive and is best for servers or mission critical systems.

All UPS use batteries to supply power in the event of a failure with special circuitry to emulate AC line power. Check the UPS power and time ratings carefully as they typically only provide their rated power for between 5 and 20 minutes. This is only good enough for the short-term. It will get you past a quick brown out or gap or allow you to gracefully shutdown your systems. However, you must monitor and maintain your batteries. Over time, your UPS battery’s effectiveness will lessen and you will need to replace them about every 3-4 years. If you actually use your UPS and the battery is significantly drained, the lifespan of the battery will be much shorter. I recommend placing a date label (or writing with a Sharpie right on the UPS) on the UPS to remind you when new batteries might be in order. Many models have warning lights or other methods to warn you as well.

If you need to keep power up for longer than a few minutes, you must consider a power generator and automatic switching equipment. At this level, you will likely want to consult a qualified electrician or power engineer but it doesn’t have to be super expensive. Residential or small commercial generators with auto-switchover systems can be obtained for $3000-5000 and can run for hours. Natural gas, propane, gasoline, or diesel generators are available in various capacities. I’ll cover generators in greater detail next time.

Lee Le Clair is the CTO at Ephibian. His Tech Talk column appears the third week of each month in Inside Tucson Business