10 amp fuses - quick moan

[Owain Lastname]

We don't have many BMWs.

Owain

[Andy Burns]

Send him this link, or clive's video

[SH]

actually, aren't some Moulded IEC leads only rated for 10A? so 5A to 13A would be too big a jump so 7A or 10A fuses could be appropriate here?

[John Rumm]

They seem to come pre fused at either 13A or 5A these days....

(the really dodgy ones are unfused!)

[Owain Lastname]

Already have.

Owain

[SteveW]

I'm glad to say that I've only seen one of those.

[John Rumm]

They are usually easy to spot - very small, almost triangular plug with very little extra body around the outside of the pins. Quite often sport a partially insulated earth pin as well.

[Animal]

I don't know any domestic portable appliances that run on a 32A fuse. (Except welders where someone replaced the fuse with a bolt.)

[Animal]

In reality there is plenty of kit that's not fully safe on a 13A fuse. Historic goods, noncompliant stuff & extension leads are not uncommon. To assume everything is ok on 13A is simply wrong. Yet many that ought to know it don't.

[Andy Burns]

You get plenty of unfused C14->C13 leads used in server racks, fed from 20 way PDUs with a 32A commando, often on a type C MCB to prevent trips when half a rack of servers get energised at once ...

[Scott]

Are they suited for use in countries with different wiring systems? Do any countries use 16 amp radial circuits and square pin plugs?

[Scott]

My understanding too. Does the same not apply to some power strips?

[Mark Carver]

Yes, in some Middle East countries, they use BS1363 plugs and sockets etc, but that's about as far as it goes adopting UK style standards.

I've been presented with power feeds where all three conductors are black. 'Live' is quite easy to reasonably assume, but Neutral and Earth are trickier !

[Mark Carver]

Or sequential switched PDUs, the more elegant way of doing it. Back in the days of studio galleries and OB Trucks with CRT monitor 'walls' they were a must, to avoid trouble with 32 simultaneous de-gauss bursts !

[Andy Burns]

The servers themselves can often be set to use random turn-on delays, but it was the PSU caps charging before boot when returning from weekly generator test that tripped the B curve MCBs ...

[John Walliker]

The 32A example I was thinking of was a device connected to the fixed wiring such as a Bluetooth controlled relay box. John

[lacksey]

Yep, no need for plug fuse with radial as opposed to ring mains.

Plenty do have the same plug format but usually 10A radials, mostly ex colonies.

[John Rumm]

Indeed, as mentioned.

Although as a proportion of the whole, I would suggest the amount actually in use is tiny. The vast bulk of the explosion of small appliances that fill most homes, has occurred in the last 30 years, and in that time most of that same kit will have been sold into multiple markets in addition the UK.

If it can be sold in the same configuration elsewhere, then it won't be designed to rely on the presence of a fused plug.

Which one must assume is unsafe under any circumstances, unless you have the ability to test and inspect it and prove it satisfactory.

I don't recall anyone suggesting "everything" is ok on a 13A fuse.

I expect it is actually the other way around!

Few will understand the distinction between overload and fault protection, and what role a plug fuse plays.

Assuming they give it any thought at all, they are more likely to believe that because it is a low power device with a skinny 3A flex that it *must* be fused at 3A. Even though in most cases that might not actually be true, the outcome is safe since there is not usually any harm done fusing more closely than is actually required.

[John Rumm]

That depends a bit on how you interpret that :-)

The reality is that they are just very cheap tat sold to the unsuspecting. They purport to comply with BS1363, but don't - even though they will physically fit in the socket.

Yes, the UK for example... :-) (we also use and 20A radials and 32A rings - plus a few other less common configurations)

Now there *may* be countries that have adopted BS1362 plugs and sockets, but also never place them on a circuit protected above 16A. However even that does not justify the dodgy plugs since they typically fail compliance on a number of issues, not just the lack of a fuse.

If you compare the unfused ones to the actual physical specs, all those I have seen fail to meet the required tolerances like having at least

9.5mm annulus of material around the L & N pins:

[Animal]

There's a fair bit of pre-1970 portable lighting still about.

It covers the full range from some trivial issue to omg you're not plugging that in. Plenty is in the former lot.

There's no shortage of folk insisting everything's safe on a 13A fuse.