On Friday, November 9, 2012 2:37:00 PM UTC, charles wrote:
In article ,
whisky-dave wrote:
On Friday, November 9, 2012 1:58:11 PM UTC, Mike Tomlinson wrote:
In article ,
whisky-dave writes

True but how do you calculate the minimum fuse necessary, it's not
always that
easy.

Yes it is, you look at the appliance rating plate and if it's in watts
not amps, apply Ohm's law.

So what fuse do you put in a fan that's rated at 50W a 3 amp ? As that's
what's in the fan we brought and it has been PAT tested and passed.
for me 50/230 is NOT 3 So are you saying I should put in a ~250ma fuse
instead ? As that's how I'd calculate it, but I'd put a 3 amp fuse in the
plug as that's what the manufactuer did.

You forgot the switch on surge. the 50w is the running power

Exactly. There's also availability, and the fact that fuses below 3A often die of their own accord over time.


NT