Why are there fuses in British electrical plugs?

The Workshopshed blog writes about a conversation on Mastodon which started as to why the USA have communal laundry rooms in their apartment blocks and diverged into a discussion on UK home wiring, raisng the question. Why does the UK have fused plugs and how does everyone else manage without?

Looking around my house, I realised that not everything that fits in the socket has these cartridge fuses. And I think this is a big clue to why the fuses are there.

It is because of the ring main.

One commenter was insistent that the reason the fuses were there was because of the ring design of our socket wiring. This statement is repeated around the internet, but it didn’t seem like the whole answer to me as there’s nothing inherent the ring topology which means we need fuses.

The fuses in UK plugs are 13A for large appliances and 5A or 3A for smaller devices. There are certain devices such as AC to low voltage DC that don’t have fuses, sometimes known as “wall warts”. The key feature of these is that they have no wire between the device and the plug, so there is no wire to protect. As the only output is low voltage these devices often don’t have an earth either. These devices have multiple layers of casing to protect the user from any possibility of exposure to high voltages.

So in summary, the UK has fuses in their plugs so they can do their laundry at home.

Read more in the post here.


Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 38,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — JP’s Product Pick of the Week @adafruit @johnedgarpark #adafruit #newproductpick

Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: MicroPython v1.24.0 is here, a Halloween Wrap-up and Much More! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

Adafruit IoT Monthly — Halloween, WiLo, and more!

Maker Business – Adafruit Daily — First Solar’s $1.1 billion development of vertically integrated factory in the U.S.

Electronics – Adafruit Daily — Oscilloscope Jumble

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



No Comments

No comments yet.

Sorry, the comment form is closed at this time.