10 Ways to Anticipate and Survive a Power Outage
Issue
It's getting harder and harder to ensure a supply of clean, continuous power to the modern IT infrastructure. Demand for power is rising rapidly and is straining antiquated utility-company grids. It takes more than 10 years to bring a new power plant online, and utility companies are in no hurry to make such investments. Add to the narrowing gap between supply and demand the increasingly distributed nature of corporate IT assets, and you have a power conundrum that is difficult to deal with. How can you evaluate the risks of various types of power problems, and what can your company do to protect against them?
Strategies
1. The first step is to identify systems that would have a critical effect on business continuity if they went down due to a power outage. These systems may include those related to sales, logistics and customer service.
2. Next, look for symptoms of power problems below the level of a total outage that may indicate high risk of an outage. Such symptoms include frequent, inexplicable reboots; an unusually high rate of equipment failure; high numbers of user complaints about lost data; and sudden shutdowns. Very often, such glitches are signs of a strained power system that is experiencing transient outages or fluctuations in voltage and current.
3. Pay attention to the external environment. Is there a lot of construction going on around your building that could lead to a accidentally severed power line? Are thunderstorms, blizzards and other weather events common? Is your building and its wiring more than 20 years old? All of these are signals of vulnerability to power outages.
4. You can assume that the power coming into your system is not "computer grade." Utility companies are allowed considerable deviation in voltage levels from the specified 110-volt to 120-volt range. The average location experiences several such undetectable variations from this range each day, enough to shorten the life span of delicate network and computer equipment. You need to condition your own power supply.
Voltage spikes are the most common worry, as they can burn out electronics. Surge suppressors work to shut down spikes before they can do damage, but undervoltage dips also take their toll, and surge suppressors do nothing to stop them. Dips are less easily detected than spikes and therefore may go without remedy. But voltage dips should be corrected before they cause losses of data.
5. A UPS (uninterruptible power supply) is considered the best protection against voltage dips, brownouts and blackouts. But there are three different types of UPS, and the differences are important.
- An offline SPS (standby power supply) delivers power directly from the grid until power fails. Then, a battery-powered inverter switches on to continue supplying power. Note that during normal operation, an SPS does not smooth out voltage sags and spikes in the grid power. An SPS is not suitable for mission-critical servers, but because it is so inexpensive, the technology is often used to protect desktop workstations against power outages.
- A line-interactive UPS conditions grid power using a Ferroresonant transformer. The UPS maintains a constant output voltage given varying input voltage and also filters out line noise introduced by motors and other devices on the circuit. Like an SPS, a line-interactive UPS switches to battery power if it experiences a significant dip or spike in grid power. It offers adequate protection as long as significant voltage variations do not occur with high frequency in a short period of time, in which case the battery might not have enough time to fully recharge. Battery time would then be reduced in the case of an extended brownout or blackout.
- A true UPS supplies power from an inverter continuously. There is no switchover time from grid power to battery power, and a true UPS can provide voltage regulation and line-noise filtering. The true UPS system supplies high-quality power under all conditions and recharges its battery continuously, providing the highest level of protection to mission-critical computing equipment.
6. Private generators are another way to prepare for power outages. Generators typically come online 10 seconds to 30 seconds after a power outage begins, with the time gap being filled by UPS systems. Generators provide protection against longer-term power outages that may last several hours or even days. Many datacenters have redundant generators, and some even have redundant fuel suppliers to keep their generators running during unusually long outages.
7. During a major power outage, some systems should be shut down in an orderly fashion to conserve emergency power for mission-critical systems. Software products such as the Atlas suite from MGE UPS Systems can continually monitor a network, detect power events and execute orderly shutdowns of specified devices remotely. The software can also alert system administrators of power events via SMS, email, pager and other communications channels.
8. Testing is a frequently neglected part of power-outage readiness. All systems should be tested at least once per month, as well as after any major power event.
9. It may seem like a good idea to bury above-ground power lines to protect them from the elements, but this tactic can actually be counterproductive . Underground lines quickly build up heat and must be bathed in oil to keep them from overheating. The oil must be kept clean with filtering, yet another point of potential failure. Underground wires are also vulnerable to backhoes, and they can be much more difficult to repair than above-ground wires.
10. Today's enterprise is increasingly dependent upon outsourced datacenter services. It is critical to know what power-protection measures your service provider maintains and how the connections between the datacenter and your facilities will be handled in the event of power outages. Which party is responsible for which legs of the connections?
The Bottom LIne
Power protection can be a tough sell to management. After all, it is a big expense to protect against an event that will hopefully never happen. But the odds are that your business will experience a major power outage in the not-too-distant future. It pays to prepare now for that eventuality.
