Voltage Spike

A voltage spike is defined as fast short duration electrical transients in voltage. All electronic and electrical devices are designed to operate within a certain voltage power supply, which is normally written on the product sheet/manual or on the device itself. Voltage spikes can damage these devices. One of the more common types of damage that can be seen is when a bulb is given a supply of power higher than its voltage rate, causing a burn out of its wire or even causing it to burst into flames if there is an over-voltage.

Voltage spikes can happen through natural causes, such as lightning strikes, solar wind and solar flares. A surge in supply within power, phone and signal lines can affect equipment over large areas. A storm that is occurring miles away can induce high voltage spikes in another location. Lightning doesn’t just cause surges when it strikes, lightning between storm clouds can also create magnetic fields that induce surges.

Man-made over-voltage is caused by electromagnetic induction when switching on or off inductive loads (like electric motors or electromagnets). Power outages, tripped circuit breakers, short circuits Electromagnetic Pulses (EMP) with its energy distributed up to 100 kHz in 1 MHz frequency range and inductive spikes. Surges in the power lines can also be generated at the switching station of a local power company. It can also be generated by electrical machinery, appliances and power company operating equipment. Common household equipment can generate 1,000 Volt spikes.

Equipment such as computers, phones, TVs, gaming consoles and home theatre system are at risk from voltage spike damage. The increase in use of microprocessor chips which are highly sensitive to voltage variations makes it even more important to use surge suppressors or protectors. Surges can also cause long term degradation of internal circuitry. This kind of damage cannot be observed and accumulates over time, causing the equipment to perform poorly.

So how do you protect equipment from these voltage spikes?

There are types of protection that you can purchase for these sensitive appliances, such as AC power protection, modem and phone line protection and network, data and signal line protection.

AC Power Protection
AC power protection features a clamping voltage (let-through voltage). The value of the clamping voltage is the limit of voltage the metal oxide varistors (MOVs) inside a protector will let through before it conducts electricity to the ground line. The metal oxide varistor (MOV) contains materials such as granular, zinc, and oxide that conducts current (shorts) when presented with a voltage above its rated voltage. In order to avoid fire hazards, MOVs are thermal fused or otherwise protected. Most AC power protection equipment have a clamping voltage of 330 volts on a 120 V AC device. They can also be valued at 400 V and 500 V.

Surge suppressors or protectors that work on the AC protection concept can be used to protect electronic/electrical equipment. These suppressors come in the form of either a strip or box and have several power outlets for appliances to be plugged into. The power supply to these appliances is made constant through the suppressors by grounding any voltage spike above the safe threshold. A metal oxide varistor (MOV) built within diverts any extra voltage that is being channeled from the power lines to the equipment through the suppressor. A surge protector can have surge amp suppression capability ranging from 4500 to 50 000. The higher the surge amp value, the better protection you are getting.

Since a voltage spike can be caused by power outage, another way of protecting electronic equipments is to use a power supply backup device (or uninterruptible power supply-UPS). A power supply backup device such as the UPS provides power from a separate source when utility power is not available and offers protection from a momentary power interruption. It typically provides 5–15 minutes of uninterrupted supply until an auxiliary power supply can be turned on, utility power restored, or equipment safely shut down. The UPS is always recommended for computers because it allows you enough electricity to safe your work before the computer dies.

Modem and Phone Line Protection
Phones are prone to surges and voltage spikes because the electronics inside a phone are very sensitive. Modern telephones damage easier, because the electronics within these phones break down more easily than the older phones with just transformers, carbon microphones and mechanical rotary dials. The phones of today are all thin wires and computer chips.

Modems are even more sensitive than phones and burn out more often from surges because they have delicate electronics in them and are connected to computers, which are connected to the power in a house or building. Phone lines have a current running through them but nothing as strong as the power running through a house. For these reasons modem electronics are prone to be damaged by both differential and common mode surges. A surge can enter a modem 2 ways, either through a telephone cord that is inserted into the modem for internet use or through the main power which the computer itself is plugged into. Your main concern should be the main power cord. This should be connected to a surge protector. There are surge protectors for internet cords and to get one would be wise, but the chances of a surge frying your modem are higher through the main power cord.

Network, data and signal line protection.
Another option is to install external surge suppressors that not only protect the modem (which can be replaced cheaply) but protect the whole system itself, such as the network, the PC (which holds data) and the lines themselves (which can be expensive to replace). Valuable information and data that is lost is hard to replace, and a large computer system in an expensive business needs this extra protection.

DCPowerSupplies.org