Hello All!

Have been doing a little job at the British Legion today.  The club needs a Periodic Inspection so I am helping to make this happen.  I was working on the main distribution board and found something that may be of interest to the to the regular ‘Part P’er’ who doesn’t venture into factories and the like……

Now of course you come across and fit protective devices every day, but these are special. Like £15 each special!  It is a BS 88 fuse, which in class, I call the Arnold Swarzenegger of fuses!  And why would I heap praise on this little beauty?

Well of course you can have a big bang on a job, whether caused by you or not!  On a domestic installation, the biggest fault current I have ever seen was 3,000 Amps.  Funnily enough this was on the mains featured in the latest instalment of the  ’Part P Doctor’…. Anyway , it is no big deal as you know that an mcb or fuse can easily cope with this potential fault current.  However, when you go into industry you will find that 3,000 is nothing much and can be far higher.  The BS88 fuse is AKA a HRC or HBC fuse.

These acronyms stand for ‘high rupturing capacity’ or ‘high breaking capacity’ and there is the whole story.  These types of fuse can safely break up to 80,000 Amps.  Yes you just read that right…… EIGHTY THOUSAND AMPS!

So, why £15 for a fuse.  Well that may have a little to do with the high quality silica sand filling of the fuse chamber or perhaps more to do with the fact that the fuse wire inside is silver…..  Cue “Ah ha Jim lad” ala Treasure Island!