How not to let your electrical system catch cold
Categories: UPSsRob Morris argues that power systems - like computers - need to be protected from viruses
Everyone is familiar with software viruses and the damage they can do - and most take steps to prevent them. Sadly, there is nothing like the same awareness of power viruses and the fact that they too not only cause damage but are far more widespread than people think. Software viruses are common occurrences in the computing world.
They enter a system unseen, often incubate in silence, and eventually come to life with results that range from merely annoying to disastrous.
Electrical disturbances are quite similar.
In fact they can reasonably be called ‘power viruses’ as they, too, are unseen and can cause serious and expensive electronic system failure.
Power viruses are contracted in the same way as other viruses.
They are passed along - often by your system’s electrical neighbours.
Plug your equipment into the wall, turn it on, and beware.
You could have just been exposed to an unseen epidemic, one where there are a lot of very sick electrons looking for ways to cause problems.
Some them may take time to cause noticeable damage.
Others are immediately catastrophic (like a lightning strike).
How do power viruses affect an electronic system and what can you do to prevent them?.
First it is useful to understand them.
Then you can begin protecting your system against their harmful effects.
There are six main power viruses that can invade a system.
The symptoms they cause can vary as can the correct course of treatment.
The first class of viruses is made up of voltage spikes and impulses, and these are usually caused by your own electrical equipment.
Electrical loads like elevators, motors, relays, induction furnaces, copiers and similar devices can cause sudden large increases in voltage within an electrical system.
External factors, such as switching changes by the local power utility and lightning strikes can cause transient impulses so intense that they literally cause sensitive microcircuitry to ‘blow up’.
This type of virus is fatal to electronic systems - but not always immediately.
Sometimes voltage spikes and impulses are relatively small and, cumulatively, the system components are weakened over time leading to deteriorating health and eventual failure.
At other times the impulses may be so large that they cause immediate system failure.
Secondly, the electrical noise virus, like voltage spikes and impulses, is usually created by your system’s electrical neighbours.
Almost every electricity-consuming device contributes its share of electrical contamination.
Things like appliances, photocopiers, laser printers, and electronic lighting ballasts are all noise sources that can cause computers to lock up, lose data, or behave unreliably.
Even computers themselves generate electrical noise.
It is a real paradox that one computer often infects other computers with power viruses.
Third comes the common-mode voltage virus.
And as its detection is relatively easy, more system problems are traced to its existence.
The condition is characterised by unwanted voltage measured between neutral and ground in the electrical system.
In practise, the common-mode voltage virus is probably the most serious one infecting electronic systems today.
It is a result of high impedance, neutral conductors shared with other circuits, and branch circuit lengths that are excessive.
When the electrical noise virus (already mentioned) appears between the neutral and ground conductors it becomes a common-mode virus, which can result in cause lost files, system lockups or reboots, communication errors, and ‘no fault found’ service calls.
Fourth, the voltage regulation virus is characterised by abnormal variations in the electrical circuit’s nominal operating voltage (120V for example).
These variations are generally greater than +/-10% of nominal voltage and may last for several line cycles or more.
Traditionally this virus has been referred to as the ’sag’ or ’surge’.
Typically, the virus is caused by turning on and off large loads and overloaded branch circuits or distribution transformers.
In some cases, voltage regulation viruses might come from the power utility.
If an electronic system requires tightly regulated voltage (most of today’s systems don’t) the voltage regulation virus is likely to cause system lock-ups and unreliable operation in addition to damaged or destroyed components.
At number five on the list, blackouts are the most visible and easily identifiable of all the power viruses.
They have the most obvious cause and effect relationship.
One moment power is present - the next it’s gone - and your system is dead in its tracks.
The effects of unanticipated power loss are obvious.
This is especially true if the system is a network or some other ‘fault intolerant’ architecture.
Fortunately, despite what most UPS manufacturers claim, blackouts account for comparatively few occurrences of all power viruses.
This virus (as its name implies) infects your system via a secondary path.
Even though they’re not an AC power connection, things like serial ports, telephone lines, network cabling, and I/O connections can all permit power viruses to invisibly enter a system.
The sixth and final virus causes driver chip failure and communication errors.
The back-door disturbance virus is often unrecognised.
Without treatment, serious damage can occur, and lost productivity can result in substantial financial losses as well.
Nothing can be closer to the truth that the old adage that ‘an ounce of prevention is worth a pound of cure’ when it comes to power viruses.
We all know what damage software viruses can do and we have all experienced real life viruses like influenza.
And we go to great lengths to avoid both.
We are learning to practice ’safe computing’ with regular data backups and avoiding questionable websites, bulletin boards and networks.
Most of us routinely run and update our antivirus programs.
So, why do we not apply the same care to preventing power viruses?
After all they have the same potentially damaging effect on our systems.
They enter unseen, they can cause damage ranging from annoying to catastrophic.
And like most other viruses, prevention is possible if you understand the basics.
There are five simple steps you can take to avoid catching electronic flu.
All five are required for complete immunity.
First, if there’s a magic pill to prevent power viruses, it is the understanding that a systems approach must be taken to prevention.
This means employing certain prevention techniques all at the same time.
Secondly, voltage spikes can be dealt with by a surge diverter and electrical noise by a noise filter.
However, by themselves, these are only of capable weakening or slowing down a virus - not eliminating it.
Thirdly, isolation transformers eliminate common mode voltage problems.
When surge diverters and noise filters are added to the isolation transformer, the combination will kill all three viruses.
Fourthly, uninterruptible power supplies eliminate blackouts, but despite of many manufacturers’ claims, most are not able to prevent other viruses.
Once again, the UPS must be used with the other devices to deliver total virus immunity.
Finally, the backdoor disturbance can be addressed several ways.
Fibre optic connections are one means of electrically closing the back door, but if ordinary copper wiring is used for communication, it may be necessary to employ special surge diversion techniques on these connections.
Luckily, the voltage regulation virus is no longer a serious hazard.
Once on a time, this virus was responsible for many system failures.
However, today’s systems use switch-mode power supplies.
This technology was designed as a way of reducing both power supply sise and cost while, at the same time, increasing electrical efficiency.
To achieve these goals, switch mode supplies are designed to consume electrical power differently from their predecessors.
These operational differences have created a beneficial byproduct where voltage regulation is concerned.
As a result, most systems enjoy substantial immunity to the voltage regulation virus.
Additional preventative measures (voltage regulators etc) are unnecessary.
Our dependence on sophisticated technology has created an increased awareness of the need to safeguard system integrity.
Software viruses have led to the introduction of antivirus programs and system data are routinely backed up to prevent loss.
Part of this ’safe computing’ lifestyle should be the prevention of power viruses, too.
Like other viruses, power viruses are invisible - often announcing their presence only after some initial damage has already been done to electronic systems.
Their effects can be a minor annoyance like a lockup or system error or they can be catastrophic like a blown up integrated circuit or power supply failure.
Voltage spikes, electrical noise, and common mode voltage are eliminated by a solution package consisting of an isolation transformer, surge diverter, and noise filter.
UPS and data line protection can be added to the system as needed.