Are 3A plug fuses really necessary? Why not always 13A?

[tabbypurr]

NT

[John Rumm]

BS1362 fuses are quite sloppy in tolerance:

wiki.diyfaq.org.uk/index.php/File:BS1362FusingTime.png

So the 1 sec fusing time for a 3A fuse could represent anything from say

5A to 12A

[whisky-dave]

Which is also why yuo shouldn;t use say a 3 amp fuse in a device that takes 3 amps for any lenght of time, because the fuse will run how and wonlt blow but could cause a fire which is why you'd use a 13 amp fuse now. We still have 1 , 2, 3, 5, 7, 10 & 13amp fuses but the current :-) way of doing this is to have a 3 amp fuse or a 13 amp fuse in the plug.

[Dave Plowman (News)]

I sincerely hope you never go near the design of anything.

[James Wilkinson Sword]

It's quite simple, you divide the watts by the volts and put a fuse of t= hat value (or the next one up if the result is inbetween). If the fuse b= lows when you turn it on, you need a bigger one for inrush.

-- =

FOR SALE BY OWNER. Complete set of Encyclopedia Britannica , 45 volumes.=

Excellent condition, =A3200 or best offer. No longer needed, got married, wife knows everything.

[James Wilkinson Sword]

Dunno if it was the fuse allowing >13 amps through, or the extension not allowing 13A continuous, but I've seen someone melt 4 way strips by plugging in two tumble driers and two washing machines. They really should make a 13A fuse melt if it gets 14A for more than a minute.

[James Wilkinson Sword]

For example?

[whisky-dave]

I feel the same way about you replacing triaacs all the time because you lighting system isn;lt up to what yuor doing.

You carry on replacing triacs till the end, I prefer to find out where the fault is and correct that.

[tabbypurr]

The fault is with your brain.

[RayL12]

Yes, I can see that John. Fair comment.

[whisky-dave]

I see you understand nothing and know even less.

[rajnish1978]

Sir what will happen if a European oven with 13A main fuse rating is used in India where Standard power plugs are rated 16A after changing European plug to the Indian plug

[Tim Watts]

Not much - it's close enough to be safe in my opinion. You should be fine :)

[John Rumm]

Any appliance that is sold for use in europe should be designed such that its flex has adequate fault protection from a 16A circuit breaker - since that is what would be expected in most euro countries. The UK is unusual with the general use of 32A circuits for socket circuits - and hence the need for additional fusing at the point the appliance connects to the circuit.

[The Natural Philosopher]

Nothing much. As long as what it is plugged into has a 16A fuse in it.

[Scott]

I have wondered about this. If an appliance is designed to EU specifications (with a different plug for UK models) does this mean it is designed to operate safely with a 16 amp fuse given that Euro and Schuko etc plugs are unfused and I understand circuits are fused at 16 amps.

[John Rumm]

Its ok for the "plug in" appliance itself to require protection by a lower rated fuse, but in which case it must include that fuse *in the appliance* itself - it can't rely on there being a fused plug. (note this may not apply for and appliance designed to be hard wired to a circuit)

To be saleable anywhere in Europe, the flex on the appliance will have to get adequate fault protection when protected by the typical 16A circuit breaker common in continental Europe. So this is usually done by a combination of specifying a minimum flex conductor cross sectional area, and also by specifying a maximum length of flex.