How to Protect a Computer From Power Surges

The power surges can be caused by various reasons like problems with the electrical supplying equipment. Surges may be seen more frequently in facilities with rapidly varying electrical loads, often caused by the switching on / off of electric motors, air conditioners, electrical power tools, arc welders, electrostatic copy machines or elevators. Very often, a power surges are caused by lightning stroke, close crossing high-voltage cables or static electricity. The  outdoor assembled cabling (such as local network cables between close buildings),as well as TV antennas mounted on the roofs and the Cable TV wiring are most vulnerable. In most of this cases you would suffer a serious hardware damages.

In order to provide a normal working conditions for your equipment and for you as well, you need to connect a special device, that protects the system from all kinds of electrical power disturbances. Those devises are called “Surge Protectors” and you can easily buy one from a various range of retailers across the world.In case you don’t want your work to be interrupted by a power breakdown, you could by an UPS device in addition.

Surge protectors are designed to prevent the negative consequences of power surges, saving your expensive equipment. Note that most of the surge protectors won’t survive a direct lightning strike, but they are just fine for the common everyday power disturbances. Surge protectors are placed between the device you want to protect and the wall plug or Ethernet socket. When you choose what to buy, first thing you should consider is their rapidity (Response time).

Note that when a electric power surge is present, surge protectors don’t act immediately because of the slight delay caused by the way they work. In other words the longer the response time the longer the connected equipment will be exposed to the surge. The most used composite parts used for making the surge protectors are the Gas discharge tube (GDT) and metal-oxide varistors (MOV). They have response times measured in nanoseconds which in most cases it is enough to protect your system.

A standard metal-oxide varistor protector is made of a plate of metal oxide (typically granular zinc oxide), connected to both the grounded and the main supplying cables through a couple of semiconductor elements.If the voltage is low (below a predefined level) the semiconductor material reaches a very high resistance levels and the electrons flow along the supplying cable.In case the voltage gets higher, the semiconductor gets “unleashed”, which makes him very low resistant.Then some of the electrons are diverted through the grounded conductor and the sensitive electronic equipment is already  surge protected and safe.

The second type of surge protectors – Gas discharge tubes (GDT) are very similar to the metal-oxide varistors, talking about the way they operates.The difference is, that instead of the triple semiconductor-metal-oxide system they are using an inert gas. If the voltage is low (in the normal levels) the electrons flow along the supplying cable and the connected devices work normally. In this case, we can say that the inert gas is a “weak” conductor, because the low voltage isn’t enough to ionize his electrons. However, when the voltage gets too high, the electrons flow ionizes the inert gas and it becomes a conductor, consequently it diverts the unnecessary energy through the grounded end of the protector.

As we mentioned before, the thing these two methods have in common is their operating principles – the unwanted energy is being diverted away of the circuit. But, there’s another type of surge protectors – instead of diverting the unwanted electrons flow, these devices are just slowing it down.

Uninterruptible Power Supply (UPS).

Generally, those types of devices contain a battery and a logical (electronic) block. When working in a normal mode (no power crashes) the battery is being charged by the standard electrical installation, and it’s ready to supply you with energy in case of a power break down. The logical block role is to watch out for such crashes and when detects one to provide the computer system with power form the battery. There are few different types of Uninterruptible power supplies but the most used are - Offline, Line – Interactive and Online UPS.

The offline UPS is the simplest and the cheapest one. Its role is to watch for the incoming voltage and to transfer it to the protected device if it is in normal rates. In case something goes wrong (power breakdown or over voltage), then system switches the power consumption to the battery.

The Line-Interactive UPS is a little bit more expensive compared to the Offline UPS. But it is capable to compensate the insignificant power hesitations, without the need of switching to emergency mode.

The most expensive and also most complicated UPS devices are the so called Online UPS. They have the ability to transform the incoming voltage, creating an extremely stable outgoing electric flow, which form and parameters doesn’t depend on the voltage coming from the electrical network. They are typically used in the hospitals for securing the life saving equipment.

In conclusion I want to note that a hundred percent effective surge protection still isn’t invented. Even the most expensive devices from the most famous companies cannot guarantee you a completely normal work during a power failure. Despite all, their use could significantly reduce the risk of data loss and destruction of expensive equipment.

Your safest thing to do in my opinion is at night when you are finished using your computer physically unplugs it from the wall socket. 

When there is a risk of thunder and lightening, unplug, if you are experiencing a power cut unplug your computer and do not plug it in again until the power has come back on and stayed on.

And finally if you see a lot of ESB maintenance going on in your area unplug your computer in case there is a power outage.