Does this comply.... thinker of the day!

[Darkwood]

Im bored so I thought Id get your heads thinking and take note who's posting this so Im not after a straight answer yes or no! Back your comments up please with regulations.

I have a small house and they complain when a lamp blows the bs3036 5amp wire blows and they have to replace it (nuisance tripping/blowing), the lighting is on 1 circuit and covers 5 fittings - kitchen, room, stairwell, bathroom and bedroom.. they are adamant to keep using their stock of filament lamps so for the sake of this debate we are not replacing the style of lighting nor upgrading the board or fuses...

Can i fit a 15amp or 30amp fuse wire in the lighting fuse carrier noting that under the circumstances the Zs is still in compliance and still be within BS7671 and not breaching any regs.

Remember alternative solution are off the table this is theoretical to test your understanding of the regs.

 

[GLENNSPARK]

Incorrect .....Calcs above ok but im using the 433.3 as we can tot up all the lamps and get a fixed load value ... the circuit cannot overload due to the nature of the loads on it so you can be cheeky and apply the regulation ... although it not common practice in domestic which i think is a good thing.

my only concern would be if Kev kitchen decided to start pullin a load of other stuff off it as well...`caus it was convenient`...

seen it done...

 

[shanky887614]

my only concern would be if Kev kitchen decided to start pullin a load of other stuff off it as well...`caus it was convenient`...

seen it done...

I was taught by kev at college he fancied himself as a good electrician

 

[Darkwood]

As my final note on this ... this was theoretical just to show a point that most domestic circuits don't require OL protection as they can be classed as fixed loads ... think about it how many BS3036 boards have you stripped out with copper wire in them and wandered why there is never a fire...

Having said this its good practice to implement OL protection due the nature of domestics circuits been prone to alteration and addition by both untrained and trained people.....but see most of you are on the ball today but hope it got you thinking

 

[Guest55]

well if lamp element failure is causing a brief current rush i'd just fit 5a fuse wire with a type D fault curve , job done.

didnt see that little gem coming did ya ? B-)

 

[GLENNSPARK]

well if lamp element failure is causing a brief current rush i'd just fit 5a fuse wire with a type D fault curve , job done.

didnt see that little gem coming did ya ? B-)

yep..

you definately nailed that one Biff...

 

[D Skelton]

5 bulbs @ 100W say 2.5A for cash. Over a 200m radial run wired in 1.5mm T&E to method 100 --- VD = 16mV/A/m ~ 8V ( should be 7V)

So there, forget all this fannying around with overload characteristics, short circuit dilemas and adiabatic calcuations it all boils down to knowing your voltage drops.

Its non-compliant end of ......

Erm, filament lamps mate. 525.1

Also, remember, your three and five percent voltage drop values are in the informative section of the appendices, not the normative.

Voltage drop could be taken into account for lighting design purposes but in ordinary circumstances, it isn't an issue on a filament lamp circuit.

All that said, that's a rather large domestic ighting circuit! lol

And yes, I do realise that you are being facetious

 

[Richard Burns]

Thanks Darkwood, apart from having to go out to fix and oven at the end, quite interesting.:yes: