4mm spur off ring

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m4tty

Scaredy cat™
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Hi,

Is this allowed ??

To spur off the 2.5mm ring using 4mm cable. i.e. creating radial circuit from ring.

I thought spur off spur is not allowed??

Thanks

 
Although the 4mm can handle the current, you could be drawing from a point in the ring where you`d prospectively cause overload in one of the legs of the ring.

It`d be better to take the 4mm back to the CU, or feed 1 socket only; thereby negating the necessity for 2.5

HTH

KME

 
a spur from a spur is a no no but you are asking can you take a spur from a ring and this is allowed. :D

 
I would say that you should only feed the max of 1 double unless you come off the output side of a FCU sat on the ring.

While in theory the 4mm could take more points, what happens if the ring is spilt into 2 radials down the line, this will leave your bit plus what

 
a ring is designed with a max draw of 13A at any point (or something like that). so although the 4mm can safely take the full 32A, you would be overloading a point on the ring, and if its close to one side, you could easily overload one leg of the 2.5

 
My thoughts are its better to take a spur of ring in 4 mm than extend ringmain again and again. I have been to properties that have been extended where ringmain has been extended so much readings are of the scale. Although when I am doing extensions I put new circuits in unless its a real problem.

Batty

 
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