From what we've seen so far this season, it sure looks like this summer is going to be a doozy for storms.
We've had a few blackouts already and quite a bit of rain with accompanying thunderstorms. We've only lost power here at the office once, and we happened to be onsite
earlier this month when a client site lost power for around 90 minutes.
Power problems can present in a number of forms, mainly surges, spikes, sags, brownouts, blackouts and noise, and all of these can cause varying degrees of damage to your sensitive
electronic equipment (and worse - to the data stored on your computer systems). There are a number of different products available that can help to protect against
these problems, and both your budget and the value of the systems and data to be protected will determine which products are most suitable for your situation.
Surges
A power surge is generally accepted as being a voltage increase of up to 500V that lasts around 2 seconds or less. These can be stopped by mains filters and many UPSes as well as
voltage regulators. Surges can damage your equipment by running the power supplies over their rated maximum voltage, causing breakdown of the power supply itself, and also increased
output to the internal components (for example, the +12 VDC output may run at +20 VDC, destroying sensitive components. This is even more critical with +3.3 VDC components and those
running at even lower voltages, such as RAM and CPUs.
Spikes
While power spikes run for significantly shorter times than surges - typically less than a few milliseconds, the voltage can be much, much higher. Spikes of up to thousands of volts
are common when transformers explode, cars strike power poles, and lightning strikes nearby. A direct lightning strike is likely to cause total destruction of all electronic
equipment, possibly even some that is not connected to mains power. Spikes can be limited by surge suppressors, but direct lightning strikes are likely to cause your building to
burn down and the electrical wiring to explode. Smaller spikes are also caused by fluorescent lights, electrical motors and fridges. These are all limited by the use of a surge
filter.
Sags
A power sag can occur when a nearby large load (such as a welder or air conditioner) is started. A sag usually lasts only a few cycles (and in Australia we run at 50 cycles/second)
and at a voltage from just under to about half of the normal voltage (240 Volts for single phase power in Australia). An undervoltage like this can cause equipment damage through
power supply overheating and unstable power supply output voltages. Data can be damaged as a result of unstable output voltages as well as the possibility that the power supply
will shut down momentarily if the voltage becomes too low.
|
Power Problems |
| Surge |
High voltage, extended time |
| Spike |
Very high voltage, short time |
| Sag |
Low voltage, short time |
| Brownout |
Low voltage, extended time |
| Blackout |
No power, any time period |
| Noise |
Signals imposed over a pure AC sine wave |
|
|
Brownouts
Similar to a power sag, a brownout occurs when the voltage from the power company is reduced for a long period of time. This can occur if the load required exceeds the load the
power company can deliver (this happens during peak load times) and also when a very heavy load is used (such as during building work). Brownouts can cause similar equipment and
data damage as sags, but due to the longer nature of brownouts, the likelihood for damage is greater. Both sags and brownouts can be circumvented by the use of an appropriate UPS.
There are a number of different types of UPS, and these are discussed
here.
Blackouts
A complete loss of power is known as a blackout. Unfortunately, Brisbane (and South East Queensland, in general) being where it is, we're more than likely to be affected by
blackouts over the next few months in particular. An adequately sized UPS is the only way to ensure that short term blackouts (10 minutes and less) don't affect your servers and
their critical data. If the blackout lasts longer than this, then the UPS software will initiate an automated shutdown before it has completely exhausted its battery reserves.
You could, of course, use a generator to restore a power supply before the UPS runs out of batteries, but most Small to medium enterprises don't have the funds, nor the need
to go to this extreme. If you do need to hire a generator during an emergency, Quark IT can arrange this for you and ensure that your equipment is connected correctly and safely.
Noise
In theory there should be no noise on the power lines - a clean, pure AC sine wave is what should be hitting the power connector on your equipment, with the "ground" being at 0 volts.
Unfortunately, this is not always what happens in reality. Noise can cause various issues with equipment, especially home theatre equipment, but also equipment that is connected to
serial (RS-232) devices and to equipment in other buildings. Ground loops can cause audible hum in home theatre equipment and also data loss in computer equipment. There is no easy
way around a lot of these problems, but through a thorough investigation of the equipment involved, a plan can be designed to reduce the issues to below a safe threshold.
Protection
Quark IT can supply surge suppressors that have been designed for Australian conditions. The Surge Shield range of mains surge suppressors from Thor Technologies
offer industry leading protection for your sensitive electronic equipment - from home computers and home theatre equipment to your business desktops and servers.
With access to the full range of UPS products by manufacturers such as Thor technologies, American Power Conversion (APC), Powerware (Sola) and others, Quark IT can offer a solution for
every situation - from a desktop to a data centre!
There are various other products such as the APC Line-R voltage regulators, telephone line surge protectors, notebook surge protectors and network surge protectors that can be used
to provide a further level of safety and protection for your equipment and data. Feel free to contact Quark IT to discuss power protection options to suit your needs.
For more information:
http://www.quarkit.com.au/content/view/37/51/
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