In article ,
whisky-dave wrote:
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

No I didn;t because I estimated that the switch on surge would be low for
this type of applience well low is respect of the fuse rating.

How would you calculte the switch on surge if you needed to ? How would
you allow for this value in the fuse you choose ?.

I wouldn't calculate it. It needs to be measured. and no, I don't have
the correct meter for the job.

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