Can you plug an extension lead into another?
No. Plugging one extension lead or power strip into another, called daisy-chaining, puts everything on one lead and one wall socket, and fire services warn against it. Use one lead that is long enough, or one strip with enough sockets.
0extension leads plugged into each other
1wall socket behind every chain
3,680 Wthe maximum load of Cords® strips and Extend E1
4sockets on Squared S1 and Circular C2
The short answer: no
Plugging one extension lead or power strip into another is called daisy-chaining. People do it to reach further, or to plug more in. Fire services advise against it: Dorset & Wiltshire Fire and Rescue Service says it “creates a huge fire risk”, and Kent Fire and Rescue Service says never to plug one adaptor into another.
Two things go wrong. Everything on the chain draws its power through the first lead and one wall socket, so it is easy to ask more of them than they are rated for. And every extra lead adds resistance, which turns into heat.
Add up the watts
Every extension lead and power strip has a maximum load, printed on it or in its specification. Add up the watts of everything plugged in: the total must stay below it.
Cubical C1, Circular C2 and Squared S1 are rated 16 A, 3,680 W, and Extend E1 3,680 W. In the UK, safety advice sets 13 A or 3,000 W as the limit for an extension lead.
A lamp, a monitor and a few chargers stay well below that. Appliances that heat are what fill a strip: a heater and a kettle of 2,000 W each add up to 4,000 W, over 3,680 W.
Give high-powered appliances a wall socket of their own: heaters, kettles, microwaves, washing machines.
Need more sockets?
Use one strip with enough sockets, plugged straight into the wall:
| Sockets | USB-C | Cable | |
|---|---|---|---|
| Squared S1 | 4 Type F | None | 1.8 m, braided |
| Circular C2 | 4 Type F | None | 1.6 m, braided, adjustable |
| Cubical C1 | 3 Type F | 2, 65 W | 1.8 m, braided |
| Cylindric UX1 | None | 4, 165 W | 1.8 m, braided |
Chargers take sockets fast. Four plug-in chargers fill a four-socket strip; Cylindric UX1 charges four devices from one socket. More in How to choose a USB-C charger
Need more reach?
Use one lead that is long enough, not two. Extend E1 is a braided extension cable with one Type F socket, 2 m or 3 m, rated for 3,680 W, for indoor use.
Give it one device: a lamp, a fan, a speaker. A power strip on an extension cable is a chain too, so plug the strip into the wall and choose one whose cable reaches.
A cable reel must be unwound all the way. Wound up, its cable can overheat.
Once one strip does the work, put it where it is not seen: How to hide cords at the desk and behind the TV
Questions
Can you plug an extension lead into another?
No. Daisy-chaining puts everything on one lead and one wall socket, and fire services warn that it raises the risk of fire. Use one lead that is long enough, or one strip with enough sockets.
Can I plug a power strip into an extension cable?
Fire services count that as a chain too: one extension plugged into another to reach further. Plug the strip into the wall, and choose one whose cable reaches.
How much can I plug into one strip?
As many things as it has sockets, as long as their watts add up to less than its maximum load: 3,680 W for Cubical C1, Circular C2 and Squared S1.
What should not go on an extension lead?
High-powered appliances: heaters, kettles, microwaves, washing machines. Give each a wall socket of its own.
Do I need to unwind a cable reel?
Yes. Kent Fire and Rescue Service advises unwinding it fully and leaving it loosely coiled, with air around it. Wound up, the cable can overheat.
What if one strip is not enough?
Free up sockets first: one multi-port charger such as Cylindric UX1 in place of several plug-in chargers. If you still run short, have an electrician fit more wall sockets.
Sources
Dorset & Wiltshire Fire and Rescue Service, Electrical safety; Kent Fire and Rescue Service, Electricity safety; Electrical Safety Council (now Electrical Safety First), Don’t overload; University of Aberdeen, Guidance note GN001, Electrical extensions. Product figures are from the specifications of Cubical C1, Circular C2, Squared S1, Cylindric UX1 and Extend E1.
