swa cable size?

[gt67]

Hi,

I am after a bit of help/advice with regards to the correct size swa cable to feed a home office approx 40m at the end of a garden.

Requirement to feed:

1 x pc

1 x printer

1 x ADSL modem

1 x monitor

1 x lighting cct

1 x electric heater (oil filled approx 2.5kW)

1 x radio

At the moment there is an swa cable feeding 2 garden sheds which caters for 2 x light ccts (1 in each), 4 x sockets. This is fed from the main house fuse board via 2 more fuse boards (assume they are RCD's) but not checked yet as access not yet sorted. I wasd planning to remove this existing cable so it can be fed from existing boards.

So:

Q1 - in your collective opinions and not seeing the site, does this sound acceptable?

Q2 - would 6mm 3 core swa be suitable if it is clipped directly to a wall or is 4mm OK?

Thanks for any help and advice given,

Graham

 

[Andy™]

without working out anything, id probably go with 6mm

 

[SPECIAL LOCATION]

Not enough info IMHO......

What is the earthing type?

What method of earthing are you intending for the shed?

Has the shed got any extraneous metal parts?

Why 3-core?

Would a 2-core + rod be more effective if not exporting any earths?

What calcs have you done?

Is there any probability that load may increase in a couple of years?

Whats your expected max demand?

Whats your expected volt drop?

What protective device are you using & can you meet max Zs?

Have you included Part-P notification costs?

etc..

etc..

:coffee :C

 

[Evans Electric]

I'd say you'd be good to go with 6mm. Why not do the calc for 4mm X 3c , office load is about 15A max . If the shed plugs are for a lawn mower or occasional drill I'd ignore them for the calc.

 

[Theorysparky]

i got an office 15m from house and has your spec

4mm does the job

but 6mm is what i would use for that distance

 

[kme]

Again - without any calcs, on the (very) limited info provided - 6mm. (although I would calc. it, if it were me. I`d also look at the options a la Special Location`s post above.

KME

 

[Badger]

max demand 20 amp supply is what id say, just be be careful calcs work out at :

4mm 3 core at 40 metres works out at 8.8 volts drop at 20 amp supply

6mm 3 core at 40 metres works out at 5.84 volts drop at 20 amp supply

 

[kerching]

I would have said 10mm..................only because somebody just gave me a 95m drum of it!

and nearly full drum of 16 and 10 earth

......................today was a good day...................... :coat

 

[Badger]

well if you dont want it kerching leave it on your driveway and ill call round at 2 am a pick it up when your asleep :slap

 

[kerching]

well if you dont want it kerching leave it on your driveway and ill call round at 2 am a pick it up when your asleep :slap

Too late, sorry. It looks like next weeks sub-main job has just been uprated to a 10mm one!............REEEEEEESULT! :coat

 

[batty]

I would probably use 10mm 2 core as that is what i use for most shed/office jobs gives you scope for extras if needed.