Which fuse to use as standard?

  rickf 15:57 27 Sep 2019

Hi Which fuse to use safely in 3 pin pc power cable? They seem to vary from 5a,10a to 13a> Thanks

  john bunyan 17:25 27 Sep 2019

Depends on what it feeds. Eg a table lamp etc - 3amp; TV or similar 5 Amp or irons, vacuum cleaner etc13 amp

  john bunyan 17:26 27 Sep 2019

Look a appliance brochure or instructions

  Brian Hamilton 17:37 27 Sep 2019

I tend to install these:

Anything above you tend to be in HV/LV Switching.

  Secret-Squirrel 18:55 27 Sep 2019

Rick, for your PC (and other appliances rated at up to 700 watts) you should use a 3-amp fuse.

  rickf 20:06 27 Sep 2019

Thanks guys. Might go with 5a as just checked my pc and it's fitted with that. Asking this question for a friend really and I didn't know. Thanks all.

  x13 20:34 27 Sep 2019

Easy calculations if you scroll down a bit here.

  Secret-Squirrel 09:32 28 Sep 2019

........Might go with 5a............

The UK Electrical Safety Council also say you should use a 3-amp fuse for a PC.

  alanrwood 13:14 28 Sep 2019

Remember that the wall plug fuse is there to protect the mains cable not the product. Internal fuses protect the product itself. Also it is a misconception that a 3 Amp fuse will blow if it passes just over 3 Amps. 3 Amps is its safe rated current value and will pass that ad-infinitum until it itself develops a fault.

  Peter~24 13:48 28 Sep 2019

As I understand it a 3 Amp fuse will blow "instantaneously" when 6 Amps flows through it, but will take longer to blow when the current exceeds 3 Amps, blowing quicker and quicker as the current rises to 6 Amps.


  mrgrumpy 16:01 28 Sep 2019

Hi to x13 I found your link very interesting , I recently retired from working as a tester/inspector at a vending machine manufacturer. All machines were fitted with standard 13 amp fuses because they contained either fridges or water heaters , that said , all my test benches were fitted with very sensitive rcd trips and only 5 amp quick blow fuses so that if a fault occurred during testing the trips would pop and avoid an electrical short/possible fire on the power/control boards.

Maybe its because of the job I did but when I buy anything electrical I always look at the supplied fuse rate , its surprising just how many people take the easy option and wack a 13 amp fuse in things that don't need it.

What is Markdown?

Markdown lets you add more formatting to your post. Simply type in your post and it will display as written.

If you wish to add bold or italic characters, add a hyperlink to another website, a heading or a horizontal line, simply use the relevent icons above the text input field.

A preview of your post will appear in the grey box below. If you make a change and you're not happy, simply press the back arrow icon to undo.

Post a Reply


Elsewhere on IDG sites

Samsung Galaxy Watch Active 2 review

Best Black Friday deals for designers and artists 2019

macOS Catalina: Latest Version, Updates, Problems, Fixes & Features

Les meilleurs téléphones Android (à moins de 600 €)