Comparison Defender DFS 301 vs Gembird SPX3-B-15

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.

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.

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.

The type of plug (plug) used to connect the surge protector directly to the network.

— Normal. A traditional plug for sockets, which is standardly used in Europe and the post-Soviet space. The official name is CEE 7/4, or Schuko. If the filter is planned to be connected directly to a regular household network, you should pay attention to this type of plug. Also note that in models with 400V outlets (see below), a normal plug refers to a standard 400V plug.

— UPS (for UPS). A plug designed to fit into a three-prong IEC 60320 C13 socket, also known as a "computer socket". Such connectors are often found in uninterruptible power supplies, but they are practically not used as ordinary power outlets. Therefore, buying a filter with such a plug makes sense only if it is planned to be used in combination with a UPS.

The number of sockets with type F grounding, provided in the design of the mains filter.

In this case, we are talking about full-size European type F sockets with metal ground clamps on both sides at the edges of the socket. The "socket" in this case means a CEE 7/4 ("Schuko") standard plug. Grounding is required for the safe operation of some types of electrical appliances, in particular, washing machines and other machines that work with water, refrigerators, computers, audio equipment, etc. A detailed list can be found in the reference literature. If you plan to connect such devices through the filter, this filter must have sockets with grounding.

The number of "compact" sockets provided in the surge protector design.

The compact plug (CEE 7/16 standard) has a flat shape and two round contacts. It is used in electrical appliances that have low power and do not create a large load — in particular, chargers for portable gadgets. At the same time, such plugs are quite compatible with full-size "sockets" of the CEE 7/4 standard. Nevertheless, in the design of surge protectors, specialized sockets of the "compact" type can be provided: they take up little space and can be placed even on the "excess" of free space, which is too small for ordinary sockets.

Note that full-size "plugs" are poorly compatible with compact sockets. Such a plug can only be connected via an adapter, while it is worth remembering that compact sockets are designed for low load power. So it makes sense to specially purchase a surge protector with compact connectors only if you initially plan to connect devices with plugs of the same type to it.

Availability of fastening on a wall in a network filter design. Such fastening most often has the form of a characteristic eyelet (loops), designed to be put on a nail driven into the wall or other similar detail. And the installation on the wall itself is convenient in that the filter can be quite close to the user, and besides, it does not take up space on the floor (which, among other things, minimizes the risk of stepping on the device, damaging it during cleaning, etc.) .