Can you plug an extension lead into another extension lead?
Connecting one extension lead to another is commonly known as daisy chaining. Although it may seem like a simple way to gain extra sockets or reach equipment further away, extension leads should not be connected one after another.
Daisy chaining does not increase the amount of electrical power available from the wall socket. Instead, all connected devices ultimately draw their power through the same supply point. This can increase the risk of overloading plugs, sockets or extension leads and may lead to overheating.
What is daisy chaining an extension lead?
Daisy chaining means plugging one extension lead into another extension lead instead of connecting each extension lead directly to a wall socket.
For example:
- Extension lead 1 is plugged into a wall socket.
- Extension lead 2 is then plugged into extension lead 1.
- Several electrical devices are connected to both extension leads.
Even though this provides more socket outlets, the electrical load is still supplied through the original wall socket and the first extension lead.
Why should you not plug extension leads into each other?
Connecting extension leads in series can increase the risk of electrical overload and overheating. Each additional plug and socket connection also creates another point in the electrical path where heat may develop if the connection is damaged, loose or overloaded.
Electrical Safety First recommends using only one socket extension device per wall socket and advises against plugging one extension lead into another. :chatgpt-content-reference{index="2"}
Does using two extension leads increase the available power?
No. Connecting a second extension lead does not increase the electrical capacity of the wall socket or of the first extension lead.
The combined power consumption of all connected devices still has to remain within the maximum electrical load specified for the extension lead and the electrical supply.
This means that adding more sockets does not mean that more high-powered appliances can safely be used at the same time.
Can daisy chaining cause an extension lead to overheat?
Yes. If too much electrical load is drawn through an extension lead, the cable, plug or socket connections can become excessively warm. Overloading may therefore increase the risk of heat damage or fire.
Warning signs can include:
- an unusually hot plug or extension lead
- a smell of hot or burning plastic
- discolouration or scorch marks
- buzzing or crackling noises
- damaged or melted plastic
If any of these signs occur, stop using the extension lead and disconnect it from the mains if it is safe to do so.
How many extension leads can I plug into one wall socket?
Only one extension lead should be connected to a wall socket. A second extension lead should not be plugged into the first one.
If more sockets are regularly required in one location, it may be more suitable to use a single extension lead with enough socket outlets for the intended devices or to consider having additional fixed wall sockets installed by a qualified electrician.
What if my extension lead is too short?
If the cable does not reach the required location, do not solve the problem by connecting another extension lead to it.
Instead, choose an extension lead with a suitable cable length or consider whether an extension cable or cable reel is more appropriate for the application.
For longer distances, the correct product should be selected according to the intended use, environment and electrical load.
What if I need more sockets?
If you regularly need more socket outlets, choose an extension lead that already provides a sufficient number of sockets for the equipment you want to connect.
However, the number of sockets does not increase the maximum electrical load of the extension lead. The combined power consumption of all devices used at the same time must remain within the rating specified for the individual product.
How to calculate the combined load is explained in Maximum load of an extension lead.
Can I connect a cable reel to an extension lead?
Extension devices should not be connected one after another simply to increase cable length or the number of available sockets. The same principle applies when combining different extension products.
Choose one product that is suitable for the required distance, environment and electrical load. If a cable reel is used, follow the manufacturer's instructions and observe the maximum load specified for the wound and unwound condition.
How to use an extension lead safely
- Connect only one extension lead directly to each wall socket.
- Do not plug one extension lead into another.
- Check the maximum electrical load of the individual product.
- Add together the power consumption of devices used at the same time.
- Choose a cable length that reaches the required location without daisy chaining.
- Do not use damaged plugs, sockets, housings or cables.
- Stop using an extension lead if it becomes unusually hot or shows signs of damage.
Using one suitably sized extension lead instead of connecting several extension leads together helps reduce the risk of overloading and overheating.