Too ring or not too ring, let that be the question...

[Let me think]

I'm old school and usually install RFC in domestics - downstairs ring and upstairs ring - old dog, new tricks and all that. However my eyes have been opened and see the benefits of radials, especially when it comes to small extensions.

Friend of friend, has small(ish) extension, bedroom, vaulted celling with bi-folding doors opening to the garden, so thought this would be the ideal job to break my radial virginity on 16A or 20A MCB using 2.5mm t&e. CU only has one spare way. Trying to convince them to upgrade CU as everything is off an 80A 30mA RCD - installed 2001.

'Traditional' radial (daisy-chain) pushes me close to max VD, so was consider 'branch' radial to keep VD well with inside limits - split feed at entrance to room, branch down each side of the room (four sockets one side and three the other)- some may frown upon this approach.

Extension was supposed to have a wood burner for heating, which they no longer want (cost?) as room is well 'insulated'. So just encase room gets cold, which it well, they thought they would just plug in a freestanding heater if(when) required.

Have feeling this free standing heater will turn into two further down the line.

My heart say's this isn't the job to embrace radials and one should just 32A ring it. BTW RFC here will be much more hassle (extra couple of hours in cramped, spider and mouse infested loft with rash inducing fibreglass insulation), so more than happy if someone can convince me to do radial here.

Thoughts?

P.S. Sorry for not being on in while quite, a few folks I know have passed away over the last month (non-COVID related)

 

[littlespark]

Sorry to hear of your recent bad news.

Go with the radial.... Even a couple of heaters wont break a 16A radial... 20A even better.

Itys not like its a kitchen with toaster, kettle, coffee machine, george forman, microwave etc etc


As long as future plans dont include spurring off to outside to feed the inevitable hot tub

 

[SparkySy]

Will the cable be running in the insulation as that will decrease it's ccc, could you not run it as a 32a radial? Or you are back to a ring again! You will probably be fine on a 20a as most heaters have been hit with the 2.2kw euro rules nowadays! imho

 

[Let me think]

Sorry to hear of your recent bad news.

Go with the radial.... Even a couple of heaters wont break a 16A radial... 20A even better.

Itys not like its a kitchen with toaster, kettle, coffee machine, george forman, microwave etc etc


As long as future plans dont include spurring off to outside to feed the inevitable hot tub

Thanks.

Future plan does include the inevitable hot tub, so have already ran a 6mm cable for this..overkill, but had some 'free' 6mm to use up

 

[Let me think]

Will the cable be running in the insulation as that will decrease it's ccc, could you not run it as a 32a radial? Or you are back to a ring again! You will probably be fine on a 20a as most heaters have been hit with the 2.2kw euro rules nowadays! imho

Using ref method 102.

32A radial is not an option as would be back to ring at this stage with using 2.5mm t&e.

Another vote for radial. Thanks.

 

[telectrix]

Using ref method 102.

32A radial is not an option as would be back to ring at this stage with using 2.5mm t&e.

Another vote for radial. Thanks.

thought.... you could run a radial in 4.0mm. this will solve the volt drop issue. dependent on installation method, you could downrate the MCB to 20A if you need to derate the cable.

 

[Vortigern]

Curious to know why ring final circuit will involve itchy lofty things where radials wont? Is that what you are saying?

 

[Let me think]

thought.... you could run a radial in 4.0mm. this will solve the volt drop issue. dependent on installation method, you could downrate the MCB to 20A if you need to derate the cable.

4mm would have been idea, but don’t have any to hand.

 

[Let me think]

Curious to know why ring final circuit will involve itchy lofty things where radials wont? Is that what you are saying?

Having to back up loft again, as I had initially run single of 2.5mm for sockets as plan was to run radial.

Really was look for any work around not to go back up the loft, unless absolutely necessary.

So looks like ‘branch’ radial will address my VD concerns and folks appear to be okay with a couple of heaters plugged into this. ?

 

[stevethesparks]

There seems to be a fairly recent method of thinking of trying to avoid final ring circuits? If running outlets on either side of a room, my way of thinking is to just make it a ring. Also easier for any possible extensions/additions in the future, as well as more chance of maintaining a cpc at each point in the event of a fault, and possibly saving another spare way in the CU.

In the case of this OP, would it not be possible just to extend from the existing final ring circuit? If you are trying to avoid the loft, can you not make more use of safe zones at a lower level?

 

[Dustydazzler]

I myself would always install a ring for multiple socket outlets , if it was just one double socket needed I would run a 20a radial.
i have on occasion used 4mm to run a 32a radial for a couple double sockets but that is only if I have 4mm to use up after A previous job...

 

[Let me think]

There seems to be a fairly recent method of thinking of trying to avoid final ring circuits? If running outlets on either side of a room, my way of thinking is to just make it a ring. Also easier for any possible extensions/additions in the future, as well as more chance of maintaining a cpc at each point in the event of a fault, and possibly saving another spare way in the CU.

In the case of this OP, would it not be possible just to extend from the existing final ring circuit? If you are trying to avoid the loft, can you not make more use of safe zones at a lower level?

Thanks for feedback.

Extending existing ring wasn’t a viable option.

 

[Let me think]

I myself would always install a ring for multiple socket outlets , if it was just one double socket needed I would run a 20a radial.
i have on occasion used 4mm to run a 32a radial for a couple double sockets but that is only if I have 4mm to use up after A previous job...

Thanks.

Now feeling drawn back to ringing it....

Guess I should have started a poll and go with the majority. Currently using my ask the audience life line ?

 

[littlespark]

Ask the audience? Last time it was on telly, there wasn’t one. We’re more under “phone a friend”

the only problem I see with a radial could if you have 2 branches coming from the OCPD. Next smart --- comes along, no testing, takes your 16 or 20 out and replaces with a 32.

 

[Let me think]

Thanks for all the feedback.

After chopping and change my mind. Decided to just ring it - helped by the fact the spare/un-used way in CU was 32A MCB and I didn’t have to hand a 16A or 20A MCB that would match existing MCBs (GE brand).