Power

Downtime is unacceptable and often costly. But it’s impossible to get 99.9% uptime when you plug your hardware into an AC outlet.

Power problems are the most common cause of network interruptions. According to an IBM® study, the average system is hit by 120 power disturbances per month.

Have you ever had to reset the clock on your VCR or seen the lights dim for a moment when the refrigerator kicks on? These are common occurrences that are insignificant at home but can cause a shutdown in your network. Many power disturbances are so short they’re invisible to the human eye, but they can make a router lock up or a switch require rebooting. Power problems are actually more common than you may know. For instance:
• 34% of network downtime is because of bad power (IBM study).
• 99% of power problems are brownouts (low voltage) or blackouts (complete outages). Only a UPS protects against those.
• It takes 90.87 seconds for switches in non redundant networks to recover from power interruptions.
• 45% of all data loss is caused by power problems.

For a small fraction of the cost of your networking hardware, you can purchase a UPS that protects your network from blackouts, brownouts (low voltages), and surges—even lightning strikes!

To prevent power disasters before they happen, more than 70% of servers are protected with a UPS. Network managers know that having a server down brings many operations to a halt. Although the loss of a single hub or router may not bring the entire corporation to a standstill, it can result in zero productivity for entire workgroups or remote offices.

How can you tell if your system is suffering from power problems?

See if some of these symptoms are familiar: damaged hardware, numerous service calls, erratic operation, unexplained problems, unreliable data, system slowdown, damaged software, system lockups, and more.

If you’ve experienced some of these problems, you need a UPS. It will keep power flowing, giving you enough time to shut down safely during a power outage. It will also regulate your power, smoothing out dangerous overvoltages and undervoltages, spikes, surges, and impulses that often go unnoticed. These power anomalies can be caused internally by nearby machinery, fluorescent lights, and elevators, as well as externally from nearby transformer problems, lightning strikes, downed power lines, and more.

Data and equipment losses from power problems are preventable. Eliminate system downtime and increase profitability and productivity with a UPS.

When looking for a UPS, consider these steps:

1. List all the equipment you have that needs protection. Remember to include monitors, terminals, hard drives, external modems, and any other equipment in the critical path of potential power or surge sources.

2. Add up the total amperage ratings of your equipment. This information is probably imprinted on the back of each device.

3. Multiply this total amperage figure by the operating voltage (typically 120 VAC in the U.S.) to obtain your total volt/amp (VA) requirement with a safety margin.

4. Select a UPS with a VA capacity at least as high as the amount in Step 3. To accommodate for future expansion, it’s wise to order a device with an even larger VA rating.

5. If you have questions about which UPS is right for you, contact Tech Support.

It says UL® listed, so it must be okay, right? Don’t be fooled. The $5.99 surge suppressor you picked up for your home PC may be nothing more than a multiple outlet extension cord.

UL® listed means that a product has been submitted to Underwriter’s Laboratories® for safety testing in certain categories. The strip protector you just bought is probably listed in the extension cord category. It won’t stop harmful surges from destroying equipment data.

The UL® listing for surge suppressors is UL® 1449. APC® SurgeArrest® products received the best UL® 1449 rating. Some vendors rate surge protection on the basis of joule energy. But let-through should be compared.

Basically, let-through is a measure of how much of a spike or surge each protector will let though to your electronic equipment. The lower the let-through rating, the better the suppression. And the SurgeArrest is guaranteed forever—even if it takes a catastrophic hit. It may be the last surge protector you buy.

Optical isolation protects your equipment from dangerous ground loops. A ground loop is a current across a conductor, created by a difference in potential between two grounded points, as in equipment in two buildings connected by a run of RS-232 or other data line. When two devices are connected and their potentials are different, voltage flows from high to low by traveling through the data cable. If the voltage potential is large enough, your equipment won’t be able to handle the excess voltage and one of your ports will be damaged.

Ground loops can also exist in industrial environments. They can be created when power is supplied to your equipment from different transformers or when someone simply turns equipment on and off. Ground loops can also occur when there is a nearby lightning strike. During an electrical storm, the ground at one location can be charged differently than the other location, causing a heavy current flow through the serial communication lines that damage components.

You can’t test for ground loops. You don’t know you have one until a vital component fails. Only prevention works. For data communication involving copper cable, optical isolation is key.

With optical isolation, electrical data is converted to an optical beam, then back to an electrical pulse. Because there is no electrical connection between the DTE and DCE sides, an optical isolator— unlike a surge suppressor—will not pass large sustained power surges through to your equipment. Since data only passes through the optical isolator, your equipment is protected against ground loops and other power surges.