Power Problems

Computers and other sensitive electronics are designed to receive power within a certain voltage range typically 103 to 132 volts. Power problems are electrical occurrences outside this range. The "Power Problems" graph shows the safe operating range and a representation of how each of four problems relates to that range. "Noise" is not pictured ? this problem is not a matter of rises or dips in voltage. Electrical noise is distortion of the voltage wave form, whether at a high or low level. Too much distortion results in equipment not working properly. It may also cause loads to run hot.

An Aging Power Grid A recent Electric Power Research Institute (EPRI) report "contains startling information regarding America's declining ability to deliver reliable power. It finds that escalating demands for electricity coupled with an outdated power delivery grid poses a serious threat to the U.S. economy... Unless this issue is urgently addressed, America's electric infrastructure will be seriously challenged to keep up with the demands of the information age. . . Another demand on power delivery stems from growing dependence on modern electronic end-use devices, many of which are ultra-sensitive to even minor power disruptions. Voltage sags and surges that may not affect a light bulb can cause computers to crash and can bring entire production processes or financial centers to a standstill. These and other power quality disruptions already cost the U.S. more than $50 billion annually. . ."

How Many Power Problems Should Our Customers Ignore? Disturbances in the electricity powering our customer's business systems are so prevalent and so potentially destructive, we think they wouldn't want to ignore any of them ? if they only understood what's really happening with the electricity in the building every day or what could happen if... Power problems are a very real barrier to system availability, but the relationship between power and uptime is not always obvious. This is compounded by the high variability from site to site, and the extreme weather conditions in some regions. In the U.S., the data from surveys shows the following circumstances interfering with high system availability:

• The average number of outages sufficient to cause computer system malfunction at a typical site is approximately 15 per year.
• 90 percent of the outages are less than 5 minutes in duration.
• 99 percent of the outages are less than 1 hour in duration.
• Total cumulative outage duration is approximately 100 minutes per year.

What Are Our Customer's Power Risk Factors? Here's a list of things we consider when we assess our customer's power risk factors: Experience: How often does our customer have noticeable power problems? Are they infrequent (one or two per year), frequent (twice a month), or chronic (several a week)? Building/Site: Is our customer's building greater than 10 years old? Is the utility power delivered to the building by underground means (where there is likely to be less disturbance) or by pole (where it is subject to hazards from tree branches, auto accidents, curious animals, storms, etc)? Equipment: How are our customer's office hardware and computer equipment distributed within the electrical environment? Same outlet? Same circuit? Same electrical box? Network or Modem Connections: In addition to the power coming into our customer's equipment from the AC outlet, what other lines or wires are coming in? Are they external like phone lines where surges and spikes can hit from outside the building? Are they internal between components where electrostatic discharge or transients can enter through the "back door"? Number of Components: How many components are networked together? Within the network, how many susceptibility points are there? Consider all equipment, all power lines, all data lines, and all connection points. Weather: What kind of weather is typical in our customer's area? Does it include severe weather like tornados, hurricanes, lightning storms, snow/hail/ice storms, etc? Perfect Computer Solutions Hardware Protection and System Availability Solutions Perfect Computer Solutions offers a complete line of solutions for the full spectrum of power problems that threaten hardware and system availability ? surge protection, battery back-up, unattended shutdown, power trimming and boosting, premium rack enclosures, power management software, extended-run options, scalable options, power management accessories, service programs, and more.

Sags/Brownouts Definition: Short term decreases in voltage levels. This is the most common power problem, accounting for 87 percent of all power disturbances according to a study by Bell Labs. Causes: Typically, sags are caused by the start-up power demands of many electrical devices (including motors, compressors, elevators, shop tools, other office equipment, etc). Utilities also create sags as a means of coping with extraordinary power demands, like high air conditioner use on a steamy summer's day. In a procedure known as "rolling brownouts," the utility will systematically lower voltage levels in certain areas for hours or days at a time. Effects: A sag can "starve" a computer of the power it needs to function, causing locked up keyboards or unexpected system crashes. Sags also reduce the efficiency and life span of electrical equipment, particularly motors.

Blackouts Definition: Complete loss of utility power. Causes: Blackouts occur with excessive demand on the power grid, lightning storms, ice on power lines, car accidents, backhoes, earthquakes, curious animals, falling tree limbs ? anything that cuts the power at the utility or along the way to the users. Effects: Loss of utility power means the connected equipment goes down. Businesses and customers lose system availability for all kinds of transactions. Work completed since the last save is lost.

Spikes/Impulses Definition: Instantaneous, dramatic increases in voltage. Spikes are forceful ? the tidal waves of electric current. Causes: Typically, spikes are caused by a nearby lightning strike. But they can also occur when utility power comes back online after a blackout. Effects: A spike can enter electronic equipment through the AC outlet or network data lines, resulting in catastrophic damage to hardware and complete loss of stored data.

Surges Definition: Short term increases in voltage, typically lasting at least 1/120 of a second. Causes: Surges occur when high-powered electrical motors, such as air conditioners and office equipment in the vicinity, are switched off. The extra voltage is dissipated through the power line. Surges also occur through electrical transients that arc or jump onto a network cable. Most likely all your customers have experienced that little shock upon touching metal. Effects: Surges cause quirky computer behavior and stress delicate components ? sometimes leading to premature failure.

Noise Definition: More technically referred to as Electro-Magnetic Interference (EMI) and Radio Frequency Interference (RFI), electrical noise disrupts the smooth sine wave electronics expect from utility power. Causes: Electrical noise is caused by many factors and phenomena, including lightning, load switching, generators, radio transmitters, and industrial equipment. It may be intermittent or chronic. Effects: Noise introduces glitches and errors into executable programs and data files.