What is a surge protector and how it works



High load on the grid, depreciation of network equipment, failures of electrical substations, lightning, lightning strikes close to power networks - all this leads to voltage drops. To prevent unpleasant consequences of such changes in everyday life and in industry apply network filters.

Network of the filter is flowing an alternating current and filtering in this emerging high-frequency and impulse interferences, thus it protects downstream to the network devices. Most of the standard network filters consist of two elements: it is a varistor and LC filter.


Varistor is a semiconductor resistor that converts the energy of impulse noise into heat. It is supplied by the same voltage as the protected device, since they work in parallel. The higher the applied the findings of the varistor voltage, the lower the resistance. In normal conditions, in the absence of impulse noise and normal voltage supply through the variable resistor passes a current of low intensity. When the network appears the high voltage pulse, the resistance of the varistor decreases dramatically, and at this time flows through a current of great strength.

The element LC filter designed to suppress high frequency noise (100-100 thousand HZ), which result in distortion of the sinewave of AC voltage in the network, causing interruptions in the operation of electrical equipment. Sources of RF interference can be a powerful electrical device. Such a device neighbor can connect to the network, and this will impact on your technique. In the network filters of different brands and models use LC-circuits of different power, which is measured in decibels. L is the coil inductance, and capacitor.

The differences between the different models



Filters can have a different number of connectors (1-8) to connect devices. In any case, it is better not to connect many appliances at the same time. Network filter, in addition to its primary purpose, used as the extension, so pay attention to the length of the cord.

Some models of filters are equipped with indicators system health led's. If one system fails, the led turns off.

There is a maximum current value of pulse interference that the filter is able to pass through itself, so it does not damage the filter itself and the connected equipment. There is also a maximum allowable load (the total power of all connected to the filter appliances), above which automatically fuse and network filter switches off.

Pick the model based on their needs: some filters designed for home, office, and others - for use at increased requirements to stability of voltage.