cable calc

[paul b b]

hello chaps,

would 2.5 be ok for a 10m run through house to box into swa for 15m to run a lamp post style garden light? she may also want another pir run off the same circuit.

thanks

 

[revjames]

Wattage? grouping factor? thermal insulation? Type of protective device? Cable buried underground?

Sorry Paul total overkill I know just been doing an assignment for 2391-20 and all these are factors that seriously derate cable sizes.

On the face of it assuming lamp wattage of 500W for your average TH fitting I would say 2.5mm would be more than adequate.....

 

[Evans Electric]

Yes.

 

[Apache]

Yes.

Oh, Sandra - you do make me laugh!

ROTFWL

straight to the point as always

 

[septiclecky]

Yes.

Is that yes to Paul or the Rev?

 

[green-hornet]

If you assume 500watts circuit design and clipped direct you could use 1mm cable!

Supply voltage = 230 Volts

Ib - design current = 2.2 Amps

Protective device type = MCB typeB

In - protective device rating = 6 Amps

Length of run of cable = 25 meters

Power factor = 1

Cable Type : General purpose PVC - Multicore

Installation Method : Single-core or Multi-core cables Fixed on (clipped direct), or spaced < 0.3 x cable diameter from a wooden or masonary wall

method C

Ambient temp = 30

 

[ianmacd]

(Maximum permissible voltdrop (regulatuon - 525) = 11.5 Volts)

Shouldn't that be 3% as its a lighting circuit?

 

[green-hornet]

Shouldn't that be 3% as its a lighting circuit?

Yes you are correct it should be 6.9 my fault, and thanks for picking it up I will edit accordingly

 

[paul b b]

wow thanks GH