upstairs lighting circuit

[fatty]

We've recently moved into our new (to us) house and I am looking to insulate and board the loft (and have posted separately on this matter). I have just noticed that there is a total of 26 halogen spotlamps upstairs and each one is rated 50W. That's a total of 1300W if all are switch on together. Taking the mains voltage to be 230V and assuming Power = Voltage x Current, it suggests about 5.7 amps in the circuit. The fusebox has a 5 amp fuse in it. The cabling used appears to be 2.5 mm square (solid copper) - is that called twin core + earth? I have 2 questions:

1) Is it safe as it is? I assume that if I were to switch on all the lights the fuse would pop and that would be all.

2) Would it be safe to install a fuse with the next highest rating or would I be running into trouble with heat dissipation in the cables (I realise that my calculation above assumes no resistance in the cables)?

3) Is the best option to remove the 50W bulbs and replace them with 35W lamps (totalling 910W and approximately 4 amps in the circuit)?

Thanks.

 

[sm1thson]

1) yes assuming all else is well, in prctice it might never blow at 6A (or they all would have to be on a long time)

2) normally no, but you say its 2.5mm cable, -this can take more, but i would expect that this has been added (bodged) later to put the new lights in and that the run from the fusebox and or other lights on the circuit are on 1.5 so the answer is still no.

3) yes you probably dont need that much light! and it will save on your bill -even beter would be energy saving bulbs etc.

 

[jj4091]

3) Is the best option to remove the 50W bulbs and replace them with 35W lamps (totalling 910W and approximately 4 amps in the circuit?

It depends how high your ceilings are, & I would not recommend it in rooms that need strong lighting. Why not buy a couple first & try them out to see the difference

 

[fatty]

Thanks for the help. A mix of 35s and 50s it is.