Safe zones and right angled turns?

[Bunglebonce]

Hi all.

I'm planning my rewire for the kitchen and having had a good look at the guides and forums, I still have a few queries.

1. If I run the twin & earth cable vertically down from my 45amp DP
switch/13amp socket, to below work top level and then change direction
with the cable 90 degrees to the right terminating in a flex outlet, do I
have to put a junction box and cover plate at the intersection of the
safe zones i.e where my right angled change of direction is?

2. According to my calculations, 2.5mm twin & earth will suffice from the
DP switch, as the maximum load generated by the cooker is rated at
4.12 kw. If the cable from the consumer unit forming the radial circuit
to the DP switch/socket is heavier e.g 6mm, am I ok to extend the
circuit with my 2.5mm or will it have to be the same gauge as the 6mm
or conversely, will I have to change the cable from the consumer unit to
2.5mm.

3. Can I continue the radial circuit past the flex outlet mentioned above in
1. and fit a 3 amp fused connection unit allowing connection of the
gas hob ignition flex?

4. Is their a minimum distance permitted between the edge of a gas hob
and the adjacent edge of any wall mounted electrical accessory?

5. Can I take a spur off the 45amp DP switch/13amp socket horizontally, to
feed a 3amp switched fused connection unit, to supply my extractor
hood?


Many many thanks for any help anyone can push my way and apologies for the longwinded post

 

[davy_owen_88]

This work is notifiable, so the first thing you need to do is to contact your BCO and let them know about it.

1) If you are changing directions there must be an accessory to show this - if the right angle turn occurs horizontally from the flex outlet then there is no need for the JB + cover at the turn itself.

2) The size of cable you use is determined by the fuse rating at the consumer unit. If you are running 6mm² cable I'm assuming you are fitting a 32A MCB? If so you can not fit anything less than 4mm² cable at any point on that circuit unless you fuse it down first.

3) Yes you can.

4) 300mm is the recommendation IIRC.

5) If you are taking a spur for the ignition you can not take another for the hood. It would be a better idea to feed both FCU's from the kitchen ring circuit anyway.

 

[Bunglebonce]

Thanks for the help Davy - a couple more questions if I may

a) Re Question 2. The 6mm is existing to the cooker switch/13amp socket
and yes its on a 32 amp MCB. If I swaped it to a 20 amp MCB could I
then fit 2.5mm beyond the switch and would it be ok to leave the 6mm
in place that runs from the CU to the switch.

For the record, I don't mind changing the existing 6mm to 4mm or 2.5mm, I just wondered whether it was safe to mix cable gauges so long as the lightest gauge is sufficient to cope with max load and is correct relative to the MCB rating.

b) Re Question 5. I thought that as I was just extending the radial
circuit by a single FCU, this would not be classed as a spur?
My spur (if that's the correct terminology when talking about radial
circuits) was going to come off the DP cooker switch/13amp socket, so
I assumed that would be ok?

 

[Bunglebonce]

Bump

 

[Albert]

2) The size of cable you use is determined by the fuse rating at the consumer unit.

And both by the load if i may add...