which is the besst way?

[thekingiam]

rewired all the house and forgot about light in pantry where consumer unit is.
would it be beter to run a cable from cu and put an extra mcb in, i have to put a socket in there as well from a 16 mcb so i could connect from the socket to a fcu into lighting circuit as well which would you do?

 

[thekingiam]

and work in progress

 

[steveberry11]

wouldn't want to pull back cable as i have had difficulty getting all cables to cu as it is .
as you can see not much space to drop cables. lighting cables in 25 mm trunking on the right and i need them on the left, running a new circuit from cu would save me alot of sress and effort, would i need a seperate mcb for 1 light or connect to existing mcb in cu?
View attachment 13488

You can use the feed as a draw to pull the new cable in and a new mini trunking for the switch drop (easy) or divert the supply out the side of the trunking and fit a wall mounted bulkhead.
if its that tight would it not be better to fit a length or 2x2 trunking in place of those 3 lengths
Have you taken into account the grouping factor for those cables?

 

[thekingiam]

i think i need a light to carry on so i will do it in the morning thanks guys again.:bucktooth:

 

[HandySparks]

if i connected the socket to the 32 amp ring main mcb when i come to test would i use this spur to get my readings for R1 and R2.

No.
You need to check the R1 and R2 on this spur, but this spur will be short, so will give untypically low figures for R1+R2. You need to record the highest R1+R2 for the circuit, which will be somewhere near the middle if it's a ring, or at the extreme end if a radial, or possibly at the end of a long spur off the ring.

 

[HandySparks]

could non rcd protect in mini trunkiing, but tt system so main rcd usually trips out everything first before split load rcd s in cu.

Which says to me that the "main" RCD is not time delayed. Are you intending to remove or replace it when you've finished wiring the CU? (I assume that all final circuits are protected by RCDs in the CU.)

 

[Taylortwocities]

Make that pantry light an emergency one. Then you have illum even if the RCD does trip.

Simples!

 

[ipf]

No.
You need to check the R1 and R2 on this spur, but this spur will be short, so will give untypically low figures for R1+R2. You need to record the highest R1+R2 for the circuit, which will be somewhere near the middle if it's a ring, or at the extreme end if a radial, or possibly at the end of a long spur off the ring.

If it's a complete ring, the R1+R2 should be the same throughout the circuit, surely.

 

[DaveyD]

highest R1+R2 for the circuit, which will be somewhere near the middle if it's a ring

?

If it's a complete ring, the R1+R2 should be the same throughout the circuit, surely.

Agree.

 

[HandySparks]

If it's a complete ring, the R1+R2 should be the same throughout the circuit, surely.

I think you're getting confused with r1 and r2.

 

[HandySparks]

?

If you measure R1 and R2 (or R1+R2) directly at various points on a ring, rather than by doing the figure of eight test, the maximum figure (which is the one to record) should be found at the socket outlet "furthest" from the origin, ie about half way round the ring.

 

[ipf]

If you measure R1 and R2 (or R1+R2) directly at various points on a ring, rather than by doing the figure of eight test, the maximum figure (which is the one to record) should be found at the socket outlet "furthest" from the origin, ie about half way round the ring.

R1+R2 is the result gained via the figure of eight test and should be equal at each point of the rfc.

 

[HandySparks]

R1+R2 is the result gained via the figure of eight test and should be equal at each point of the rfc.

Yes, I understand that, but are you saying that it is not permitted to measure it directly, like on a radial circuit? ie do you HAVE to use the figure of eight method?

 

[Taylortwocities]

Yes, I understand that, but are you saying that it is not permitted to measure it directly, like on a radial circuit? ie do you HAVE to use the figure of eight method?

If you want to get your R1+R2 figure then you can use the figure of 8 method
or you could add r1 to r2 and divide by 4.
The figure of 8 test (as detailed in the OSG) if the recommended method because you can check R1+R2 at each point and check polarity (also as detailed in the OSG).