View Single Post
Old 7th Jul 2019, 11:01 am   #89
GrimJosef
Dekatron
 
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,310
Default Re: 13 amp fuse for 1.5mm mains flex?

The default format for plug fuses is not slow-blow, in that the fuse wire is not loaded with a thermal mass, or tensioned with a spring, or formed in a particular way to delay the blowing in the event of a current surge. The sad fact is that the transition between a wire's continuous current rating i.e. the current which it will carry without degradation for, say, thousands of hours, and its fusing current i.e. the current needed to blow it acceptably quickly is not sharp. A 3A fuse will carry 3A pretty much for ever but it will not blow quickly at 3.01A.

The fusing characteristics are indicated here https://www.pat-testing-training.net...cteristics.php.

We shouldn't put glass-bodied fuses without sand in plugs. Their breaking characteristics are often much poorer than proper BS1362 fuses, which means an arc may continue for long enough after the wire has melted to allow serious damage to occur downstream. And they can also shatter explosively, leaving lots of sharp glass fragments to hurt you in more obvious ways.

Cheers,

GJ
__________________
http://www.ampregen.com
GrimJosef is offline