Lethal power surges, are you protected?
By: Ronel Steyn
Posted: Monday, 11 April 2006| © BusinessOwner 1997-2005
http://www.businessowner.co.za
Many computer users can relate to the frustration of losing unsaved work when a power failure suddenly shuts down their computer or network.
A more serious and insidious problem, however, is the damage that fluctuations in power supply can cause to electronic equipment itself, shortening the lifespan of the computer and potentially leading to the loss of all data on it.
Often, a very high voltage surge occurs a split second after the power is restored and this can damage computer motherboards and hard drives,? says Kevin Matthew from Wattronics, manufacturers of surge protectors.
People are not always aware of the problem, because each surge only slightly damages the computer and two months down the line the computer unexpectedly blows up.”
And whilst the recent spate of power failures has highlighted the need for businesses to protect their electronic equipment against power surges, it is not a problem that occurs only in the event of a power failure.
Voltage surges and drops can be caused by a number of factors and are a worldwide phenomenon.
They have always been an inherent part of the way in which electricity is provided. It has simply become more of a problem in recent years as the components in sophisticated modern electronic devices have become smaller and more sensitive.
Stan Upsher from AVCape, authorised inspectors of pressurized equipment, tells how a year ago, they experienced a 400 Volt electrical surge in their Cape Town based offices.
We lost two laser and two inkjet printers, two fax machines, a photocopier and a modem. The computers that were protected by a surge protector survived unharmed.
Power surges and spikes can be caused by anything from switching other electric equipment in the office on or off, to a tree or animal touches an overhead power line, to Eskom services their equipment, to lightning and of course to restoration of power after a black out.
We still don’t know what caused the tremendous power surge at our offices, says Upsher.
Corry Brits from BB Computer Back-up Services says that power surges can cause immediate damage or over a period of time.
The interesting thing about power surges is that they last less than one 120th of a second but do huge damage in that fraction of a second.?
So what can one do to protect their electrical equipment from power surges?
You definitely need USP (Uninterruptible Power Supply) to protect your computers, says Willem Swart from Pretoria Metal Pressing who design and manufacture industrial drill bits as well as weapons for Denel.
Corry Brits from BB Computer Back up services who also supply UPS devices, explains that UPS fulfills a dual role, It smoothes out power surges and spikes, providing your computer with consistent voltage and thereby extending the lifespan of the equipment.
In the event of a power failure, it also provides back up power, anything from 10 minutes to a few hours, depending on battery size, allowing the user to shut down the computer or network correctly and save any data.
But be careful when choosing a UPS device, warns Brits. There are two types of UPS devices, a true online double conversion and a line interactive UPS.
Says Swart, What you choose will depend on the equipment you want to protect and how much you want to spend. There is a huge price difference between the two.
For example, you can protect the electronic equipment of one workstation with a line interactive UPS for between R400 and R800. Protecting the same equipment with true online UPS will cost you between R2 300 and R3 000, says Brits.
The difference in functioning is that with a line interactive device there is a tiny (300 milliseconds) gap between the time the power dips or surges and the UPS takes over.
This is alright for most stand alone PCs, who don’t register that dip, says Brits, but in an environment where there is data transmission you will lose the data. If you have a network therefore, it is best to get the true on line USP.
The on line USP is also much better at protecting your equipment against surges, says Brits. As the name suggests, the online UPS is on all the time. The UPS uses the mains electricity to charge a battery and the battery in turn powers the computer.
This means that the computer is completely isolated from the mains supply and any surges that occur. The line interactive UPS works differently. It senses when there is a surge.
It works a bit like a pressure valve diverting any excess voltage to the earth or grounding wire. If the UPS becomes damaged in any way (for instance through a large surge) the computer is still vulnerable, because it is still linked to the mains supply.
Swart says that they use an online UPS to protect their server, but line interactive UPS devices to protect their stand alone computers. The decision was mostly driven by cost considerations.
Says Brits, The insurance companies accept the line interactive UPS so many companies chose that even thought it does not give 100% protection.
Even if you have invested in a UPS device, there is another device that you might consider getting, especially if your business is affected by the current spate of power cuts.
The UPS itself cannot handle the huge power surge created when the power is restored after a power failure, explains Kevin Matthew from Wattronics.
Putting a surge protector in front of the UPS will at the very least save you the cost of replacing your UPS and in the case of a line interactive UPS, will protect the computer equipment itself.
If two power cuts happen over a weekend for example, the surge following the first power cut might damage the UPS, leaving your computer vulnerable to the next surge. Wattronics sell their surge protection units for R309/unit. (ex vat)
You can load up to five amps worth of equipment onto the surge protector, which translates into one computer, screen, modem and printer.
Says Matthews, When choosing a surge protector, make sure you have complete protection at switch on.
The Wattronics device for example, completely isolates the equipment from the mains and needs to be manually reset before letting any power through. powerhouse
Upsher says that after the damage they suffered from the huge power surge last year, they have invested in more surge protectors.TOP
