Historical question WRT 15 amp sockets.

broadgage: 
 

It has been decided to leave the existing wiring largely as is. Works fine, insulation resistance and earth loop tests all good. New 25 amp fuse wire fitted in each fuse carrier.

Where the existing socket outlets do not meet present day needs, then extension leads, rather reluctantly. Installing extra outlets is not realistic in most areas due to an historic interior.

 

What happens when I plug in a small load appliance wired in 0.5 or 0.75mm2 flex using a 15 Amp plug, when the appliance become faulty? Say it internally shorts. I suppose that staff have been instructed not to do such.

Z.

This perhaps Z.

Thanks Z.

Z.

What happens when I plug in a small load appliance wired in 0.5 or 0.75mm2 flex using a 15 Amp plug, when the appliance become faulty? 

Well it goes ‘bang’ in the best comedy tradition. Racing a bit of 25 A or 30A fuse wire against a 0.5mm2 flex, the fuse will always win, but internal heating means the cable may well be put beyond re-use. (true even for 1mm2 wire under some conditions)  But the defective appliance is probably going in the bin anyway, so the cable can go with it.

A bigger issue is overload - a short circuit to earth part way along a heating element may result in a lot more current than intended, but not enough to bother the fuse.

RCDs help that situation of course.

Mike.

Not a few of these ? As seen in ZA, India etc. Accidents are rarer than you think considering what is in daily use elsewhere. Not so keen on the earth free Schuko there I must admit.

The only appliances likely to be plugged directly into the 15 amp sockets are  heaters. And two standard lamps but these are fitted with 15 amp plugs that contain a 5 amp fuse.

Everything else has 13 amp plugs and is used via extension leads. 1.5mm heavy duty flex from a 15 amp plug into a multiway trailing 13 amp socket. These trailing sockets incorporate a 13 amp fuse. 

Two such leads used at the same time and fully loaded is a bit unlikely, but if it did happen is only a 1 amp overload.

The existing MICC cable is terminated into cast iron boxes, these have a custom made hardwood front cover in which are mounted the two 15 amp sockets.

Disturbance to update is not wanted in the upper floors. PARTS of the ground floor can have new wiring installed from below.

I'm hoping it's just the persepective making a 3-pin plug looks like a 2-pin one…

   - Andy.

It sounds like a most interesting building. Pity it could never be let out! ?

broadgage: 
 

The only appliances likely to be plugged directly into the 15 amp sockets are  heaters. And two standard lamps but these are fitted with 15 amp plugs that contain a 5 amp fuse.

Everything else has 13 amp plugs and is used via extension leads. 1.5mm heavy duty flex from a 15 amp plug into a multiway trailing 13 amp socket. These trailing sockets incorporate a 13 amp fuse. 

Two such leads used at the same time and fully loaded is a bit unlikely, but if it did happen is only a 1 amp overload.

The existing MICC cable is terminated into cast iron boxes, these have a custom made hardwood front cover in which are mounted the two 15 amp sockets.

Disturbance to update is not wanted in the upper floors. PARTS of the ground floor can have new wiring installed from below.

This illustrates just how good quality materials properly installed can last and last. Very impressive.

Z.

Chris Pearson: 
 

It sounds like a most interesting building. Pity it could never be let out! ?

Probably not as residential accommodation,  but the property is fairly regularly used for filming, which is another reason for not adding modern electrical accessories. An actor involved in filming stayed in one of the guest rooms, and finding no power sockets they sent for a B22 adaptor in order to charge something from the bedside lamp. It did not work. A little investigation would have shown that the bedside lamp was fitted with a 12 volt LED bulb and connected to a 12 volt dry battery.

The Semi basement kitchen has modernish wiring, rather badly done with renewal planned, but the rest should be good for another 100 years.