Shed Electrics

[optician]

Electrics to shed. No water or gas.
Consumer unit in the middle of the house at the bottom of a nicely decorated wall with concrete floors.
In other words, no chance of separate circuit.
All earthing present and correct.

Rcd covering kitchen circuit and others.


Thinking of connecting to said 4mm kitchen radial on a 32 amp breaker Zs .32 at this point(Double socket)
Run another 4m in 4mm t&e(under units) to outside wall.
Connect to 6mm 3 core swa for 30 m (down and under garden) to brick shed to supply a 20 amp radial and 6 amp lighting circuit. metal consumer unit.
Any thoughts greatly appreciated.

Dave G

 

[Pete999]

Can you not exit through the rear of the CU or just below or above and form a new circuit? or is the CU full to capacity? it's just a thought, you could then exit the CU in PVC/PVC and joint to the SWA in an adaptable box, not being able to see the set up. it's only a suggestion.

 

[simpson93]

Why the 6mm armoured and not 4mm?

 

[Pete999]

Why the 6mm armoured and not 4mm?

No mention of any measurements so could he be concerned with volt drop, but like you said why 6 and not 4

 

[simpson93]

Either way it's far from ideal to have it on same circuit as kitchen

 

[Pete999]

Either way it's far from ideal to have it on same circuit as kitchen

Agree with you on that

 

[Leesparkykent]

In an ideal world it would be a new circuit but sometimes you've got to just work with what you've got. You would want some kind of double pole isolation in the house as in the event of a fault you would want to be able to isolate the outside part of the circuit so as not to affect the kitchen/other circuits on the same RCD. What's the design current of the brick shed? For example is it one light, one double socket or multiple sockets that are going to run heaters, tools, etc. How long is the existing 4mm² kitchen radial to base volt drop calculations on?

 

[optician]

The CU is full andI cannot run a new circuit as the cu is on the party wall of a semi.

 

[Pete999]

The CU is full andI cannot run a new circuit as the cu is on the party wall of a semi.

OK Ta that rules my idea out

 

[optician]

Yes 6 mm as i wanted to minimize volt drop, but also wanted a zs at shed that was low. As the point of connection to the kitchen
circuit there is already .32 impedance.
The kitchen circuit is protected with an Rcd which covers others so if in future there is a prob with the circuit tripping others i
can put it in its own CU. Its the cable i have no chance of running.
Only computers in shed with lighting no heavy heaters etc

 

[David M]

As Leesparky said, I'd definitely put a double pole isolator with easy access as near to your supply connection as poss.

 

[Andy78]

If the supply is to be taken from an existing circuit I would not bother with the garage CU I don't think. Just fuse down for the lights from the extended circuit.

 

[Leesparkykent]

Yes 6 mm as i wanted to minimize volt drop, but also wanted a zs at shed that was low. As the point of connection to the kitchen
circuit there is already .32 impedance.
The kitchen circuit is protected with an Rcd which covers others so if in future there is a prob with the circuit tripping others i
can put it in its own CU. Its the cable i have no chance of running.
Only computers in shed with lighting no heavy heaters etc

With a Zs at the point of connection of .32 using 4mm² 3core swa on a 32A type B mcb using the 3rd core as a CPC would roughly give you a maximum length of around 69 meters from the point of connection. Probably wouldn't comply for volt drop though.

 

[optician]

Many thanks All for your responses.
Dave G

 

[telectrix]

aas previous posts, fit a 13A SFCU next to socket, then cable to shed direct to sockets, then FCU @ 5A down for loghts.