Surge current ratings for extension leads explained

Surge protected extension leads are available with different maximum surge current ratings. This value, stated in amperes (A), is one of the technical specifications used to describe the capacity of the surge protection circuit when dealing with short-term surge currents. The rating can help when comparing different surge protected extension leads, but it should not be considered in isolation. The devices being protected, the design of the protection circuit and the overall surge protection concept are also important when choosing a suitable product.

What does the surge current rating of an extension lead mean?

The maximum surge current indicates the surge current the protection circuit is designed to handle under its specified test conditions. When a voltage surge occurs, components inside the surge protection device are designed to limit the voltage reaching the connected equipment and divert surge energy through the protective circuit. A higher maximum surge current rating generally indicates that the protective circuit is designed to handle a greater surge current capacity, but this figure alone does not describe every aspect of surge protection, so the complete product specification should always be considered.

Why do surge protected extension leads have different ratings?

Different applications can require different levels of protection. An extension lead used for everyday electrical equipment may have different protection specifications from a product designed for valuable computers, entertainment systems, network equipment or other sensitive electronics. brennenstuhl® therefore offers surge protection products with different maximum surge current ratings, while the exact values and product combinations available can vary depending on the model and product range.

Is a higher surge current rating always better?

A higher surge current rating represents a higher specified surge current capacity, but this does not automatically mean that the product is the best choice for every application. The appropriate solution depends on what needs to be protected and which other features are required. The number and arrangement of sockets, interference suppression, switching functions, USB charging and the intended installation location may also influence which surge protected extension lead is most suitable.

How much surge protection do I need?

The required level of surge protection depends primarily on the equipment being connected and how important it is to protect that equipment against voltage spikes. Sensitive, valuable or difficult-to-replace electronics can justify choosing a product with a more comprehensive surge protection specification. Rather than selecting an extension lead purely according to one numerical value, compare the complete technical specification and consider the connected equipment as a whole.

The basic causes of voltage surges and how protection works are explained in What is surge protection and why is it important?.

What does 13,500 A surge protection mean?

A maximum surge current rating of 13,500 A means that the protection circuit has been specified for this maximum surge current according to the relevant product specification. brennenstuhl® uses this protection level in selected surge protection products intended for a range of everyday electrical and electronic applications. Whether this protection level is suitable depends on the equipment being connected and the individual requirements of the application, so the maximum surge current should always be considered together with the other technical characteristics of the product.

What does 19,500 A surge protection mean?

Selected brennenstuhl® surge protection products are specified with a maximum surge current of 19,500 A. Compared with a product with a lower maximum surge current rating, this represents a higher specified surge current capacity of the protective circuit. This type of surge protected extension lead can be considered for electronic equipment where a higher protection specification is desired, while the overall product specification and intended application remain important.

What about higher surge current ratings?

Surge protection products are also available with considerably higher maximum surge current ratings. These products are particularly relevant where valuable or sensitive electronic equipment is to be protected and a higher specified surge current capacity is required. The exact protection level should always be taken from the technical information for the individual product, as product availability and specifications may differ between ranges and markets.

Which devices can benefit from higher surge protection?

Higher protection specifications may be considered for sensitive or valuable electronics such as computers, televisions, home cinema equipment, gaming systems, routers, network devices and other equipment containing sophisticated electronic components. The financial value of a device is not the only consideration: data stored on a computer, network availability or equipment that would be difficult to replace can also make additional surge protection worthwhile.

Does the surge current rating affect the maximum electrical load?

No. The maximum surge current rating and the maximum electrical load of an extension lead describe different properties. The surge current rating relates to the surge protection circuit, while the maximum electrical load determines how much power the extension lead can carry during normal operation. A higher surge protection rating therefore does not mean that more powerful devices can be connected, and the combined electrical load of all connected equipment must always remain within the maximum load specified for the individual extension lead.

What is the difference between surge current and normal operating current?

The normal operating current is the current drawn by connected devices during regular use. A surge current, by contrast, is a short-duration electrical event associated with a voltage surge and is handled by the protection circuit for a very different purpose. This is why a maximum surge current value of several thousand amperes should not be confused with the rated current or maximum electrical load of the extension lead during everyday operation.

Do I also need an interference suppression filter?

An interference suppression filter performs a different function from surge protection. While surge protection is designed to limit short-term voltage peaks, an interference suppression filter helps reduce high-frequency electrical interference that can affect connected equipment. Some surge protected extension leads combine both functions.

The differences and the way these filters work are explained in How do interference suppression filters work in an extension lead?.

How do I choose a surge protected extension lead?

When comparing surge protected extension leads, consider the maximum surge current rating together with the equipment you want to protect and the other product features required for the application. The number of sockets, socket arrangement, cable length, switching functions, USB charging, interference suppression and mounting options may all influence the choice. The maximum surge current is therefore an important comparison value, but it is only one part of the overall product specification.