Calculating circuit load

[Octopus]

OK, got my tin hat on and have my running shoes on so I can to the bunker......

Looking at a customers "downlight" design for the kitchen/breakfast/family room. They have 32 lights marked and yes, they are planning on buying 240v x 50w fittings.

Calculating load says you should use 100w per location but surely no numpty would put 32 x 100w fittings in a room such as this so is it permissible to use 50w??

And before anyone asks they are "split" into 4 switched areas and no dimmers are required.

Thanks.

 

[topquark]

I think the rationale for the 100W per fitting came from the ability to substitute 100W incandescents for whatever was installed. So unless they can take R63 or R80 (up to 100W) then I'd say that's reasonable (tin hat on as well).

 

[Octopus]

I have suggested to the builder and the homeowner that building control may not like seeing so many 50W fittings!

 

[Octopus]

Now then you're talking, 32 x R63 or R80s's - that would look............ (insert work to suit)!!

 

[topquark]

If BC do winge (unlikely) ... If they're not dimmable then they could substitute some of the newer LED's without having to find a compatible dimmer. Even if dimmable not too much of a problem these days, just a question of getting the colour right.

 

[Guest55]

...............they are planning on buying 240v x 50w fittings.

Then that is the info you use in your calcs.Although nominal voltage is given at 230 these days
Simples.

 

[Guest55]

So , following on .....
50 x 32 / 230 = 6.9amps
oops , not gonna fit on one 6a mcb lol.

 

[topquark]

So , following on .....
50 x 32 / 230 = 6.9amps
oops , not gonna fit one one 6a mcb lol.

That's OK biff he's wiring it in 1.5mm/10A .... assume the four switched areas was both a switching and supply based decision.

 

[Guest55]

That's OK biff he's wiring it in 1.5mm/10A .... assume the four switched areas was both a switching and supply based decision.

Yeah ! live life on the edge and use a 10a mcb , welome to the world of the reckless ! Yeehaa !

 

[Octopus]

That's OK biff he's wiring it in 1.5mm/10A .... assume the four switched areas was both a switching and supply based decision.

Actually I was planning to put 1 "bank" on the existing circuit and the rest on a new dedicated circuit.

 

[topquark]

Actually I was planning to put 1 "bank" on the existing circuit and the rest on a new dedicated circuit.

Leaving spare capacity for wiring the Phasor bank in as a kitchen waste disposal

 

[telectrix]

and don't forget to allow for the photon torpedoes.

 

[Octopus]

Beam me up Scottie!

 

[Guest55]

And the forward shields use at least 4 terrawatts , that one hell of a mcb.
:-D

 

[RogertheBodger]

And the forward shields use at least 4 terrawatts , that one hell of a mcb.
:-D

It should be obvious that 4TW is not enough for the shields Biff, a couple of good hits off an enemy ship and we're down to 6A again