Thread: Fuses
View Single Post
Old 8th Jan 2007, 10:25 pm   #8
Skywave
Rest in Peace
 
Join Date: Jun 2006
Location: Chard, South Somerset, UK.
Posts: 7,457
Default Re: Fuses

My contribution to this important topic.

Mains "plug type" fuses.
As we all know these are commonly fitted in multi-way mains distribution "blocks" - typically 4-way, although 6-way and larger sizes are available. Not wishing to condone the practice of cascading multi-way dist. blocks, but where there are, in effect, several fuses in series - between the originating "13A plug" and the ultimate load, it is advisable to "fuse down" as the final load is approached. Example - 13A fuse in the primary plug, 10A fuse in the 4-way distribution block, 5A (or possibly 7A) fuses in the appliances that connect to this distribution block. Apart from the convenience of knowing where to (most likely) look first in the event of tracing a blown fuse, this also provides a safety margin for the distributed currents. But make sure that the inter-connector wiring is rated accordingly - these fuses so fitted are primarily there to protect the cabling and the inter-connectors, not the ultimate loads.

Well, that's what I was taught (in Gov't. Service).

I expect someone will make an "amendment" to my understanding - which is fine, since selecting fuses, cabling and connectors for a particular application / distribution is not a straightforward affair - as some maintain - and if nothing else, I'm a member of this Forum to learn as well as to contribute.

BTW If anyone wants to expand this Thread into "cables & connectors, mains distributions systems", please start a new Thread.
Thanks.

Al / Skywave
Skywave is offline