OT: house fires - electrical fault

That's a good point, but, this is Australia, the media are just clueless bunnies and don't know how to ask technical questions, if it didn't happen on facebook, they they have no idea who to ask, or what to ask :)

I'd love facebook to die a slow painful death, even for just a week, then these piss poor excuse for journos we seem to have today would have to get off their arses and do some REAL journalism.

Or incompetence by a qualified electrician.

Sylvia.

Note that the Circuit Breaker is there to protect the fixed wiring,

Note that in most cases this would be very impractical, as you can not normally get 10mm2 cable into a 10A socket outlet.

However 25A and even 32A breakers can be used to protect the wiring to a

That might be what the rules say, but it seems to me that its pretty illogical to have a socket and wiring which is rated for a max load of

That said, by far the most likely fault is a short circuit, in which case the current goes sky-high, and hopefully the breaker opens long before the wiring blows up.

Similar arguments apply to any external appliance.

What is to stop the cord to the toaster from turning into a heater element otherwise?

In the UK, where I used to live, the appliance plugs contain a fuse. That's 13A by default (the maximum current for an appliance), but can easily be changed to suit lesser rated wiring. That seems a sensible idea, but I've not seen it elsewhere (I think there are a few other places that use the UK style plug).

Sylvia.

For that to happen there needs to be a fault that causes excess current to be drawn, but not enough to trip the breaker. Typically, so much heat would be generated at the site of the fault that it will quickly either go open circuit, or to a complete short - hopefully before it sets fire to something.

Sylvia.

I've seen stuff done by people who consider themselves engineers that is totally dangerous. Normally by those who consider themselves above the "common" electrician.

In Aus power circuits are 2.5sq mm which is in the main 20 amps so lots of circuits have 20 amp breakers supplying numerous outlets

Fuses blow and breakers trip instantly.

.... Phil

.... Phil

• The UK commonly uses a "ring mains" system with a 32A fuse or breaker in each circuit. Appliance cables are protected by the fuse inside the plug w hich has massive conductors. This allows the use of some very thin applianc e cables ( rated down to 2 or at 3 amps )that would not be allowed elsewher e.

Over-fusing the plug is a fire hazard in the UK that we do not have.

.... Phil

Or indeed, wrapping the failed fuse with metal foil.

But at least it provides extra protection to people who aren't idiots.

Sylvia.

The Australian plugs do sometimes run very hot when used at 10A, and I have seen them where the plastic around the pins has melted. Perhaps those were not in ideal condition before they were last used (pins may have been tarnished, etc.). I regard the 10A rating as being quite "optimistic" for unattended use, and I am even more dubious about the similar versions rated at 15A.

I have also seen BS1363 plugs that have slightly discoloured after prolonged use at 13A, though the rewireable ones are usually made from thermoset materials so they don't tend to melt.

I just tested a 20 year old pair ( Clipsal 415 outlet and 463 plug) to get the above result.

If for some reason a plug and socket is running hot at 10 amps, it definitely needs replacing. The most likely reason is loose or corroded wires in the back of the outlet. Moisture is major contributor to this.

Since there can be many 10amp outlets on a single circuit, the main risk factor is with the cable in the wall and that is well protected by the usual fuses and breakers.

My experience with high current AC supply connectors is that ones that run very hot fail by going open circuit, rather than catching fire.

.... Phil

We also have a problem with unaproved imports with thinner pins(blades) on leads, chargers,power supplies etc.

I don't doubt that. Nevertheless from time to time I do see them melted. Specifically, it is usually the sort that looks like Clipsal 439 or HPM

Don't you lot have fuses in the plugs?!!!

Don't need them. Doubt we have worse accident stats.