Cable length
The length of the cable used to connect the surge protector to the network.
The longer the cable, the farther from the outlet you can install the device. On the other hand, a long cable can be inconvenient over short distances. Models on a coil are deprived of this drawback (see "Type"), this moment is compensated by the actual presence of the coil, but they differ in large dimensions and heavy weight. So when choosing, it is far from always worth chasing the maximum length of the wire.
Max. power
The highest power consumption of the connected devices that the surge protector can tolerate without consequences (to be more precise, with which it can work indefinitely without overloads, overheating, etc.).
This limitation is due to the fact that the higher the power at the same voltage, the higher the current passing through the equipment (in this case, through the surge protector); and off-design currents can lead to breakdowns and even accidents. And although in order to avoid these consequences, modern filters often provide various types of protection (see above), however, the operation of protection is still an emergency situation that is best avoided. Therefore, it is worth choosing a model according to this parameter in such a way that the maximum filter power is at least not lower than the total power consumption of the load. And it is best to have a margin of 20 – 30% — this will give additional guarantees in case of various deviations in the operation of the connected equipment.
Separately, it is worth highlighting the situations when the filter is planned to be used for the so-called reactive load — electrical appliances that widely use circuits on capacitors and/or inductors, for example, power tools or refrigeration units. The total power consumption of such devices (written in volt-amperes) can be much higher than the active power (which is indicated in watts). The recommended line filter power in such cases is calculated using special...formulas that can be found in the relevant sources.
Max. energy absorption
The maximum energy absorption provided by the mains filter, namely, the maximum pulse energy at which the device can safely absorb and dissipate it, completely protecting the connected load. The higher this indicator, the more reliable the filter, the more powerful power surges it can handle. In inexpensive models, the maximum absorption is calculated in tens of joules, in the most advanced models it can exceed 1000 J and even 2000 J.
Wire section
The cross-sectional area of the wire used to connect the filter to the network. The larger the cross-sectional area, the thicker the wire, the more reliable it is and the more current it can pass without overheating. Accordingly, thick wires (
1.5 mm² and
2.5 mm²) are a must for high power devices. At the same time, modern manufacturers, usually, choose the cross-sectional area in such a way as to guarantee the safe operation of the filter at the claimed maximum power (see above). Therefore, in fact, a model with a thicker cable than other similar devices should be chosen if it is supposed to be used in unstable networks in which power surges often occur. If the cross-sectional area seems too small for you (
0.75 mm² or
1 mm²) for the claimed power, there are special formulas that allow you to check the validity of such doubts.
