Spider Radial

[AngusSparkie]

Hi all, my first post. Just been to see a job to change a fuse box to a 17th edition CU. Did some testing to see what I'll be dealing with. All seems well apart from 1 radial that has 3 ends of line. What are my options? Do I need to make a ring with a non fused spur? or can I use the highest Zs and put it into a 20A MCB? Each spider leg has 1x 1G skt, 4x 2G skts and 3x 2G skts. The radial/spider is currently fed from a 15A fuse. Not looked for JB's etc as didn't want to lift the floor coverings. Many thanks.

 

[telectrix]

put on a 16A or 20A MCB. assuming 2.5mm cable and satisfactory Zs and IR readings.

 

[stuartcourt]

^^^^^^^^ job done

 

[AngusSparkie]

Thanks for the fast response. I was a bit worried as I couldn't find this in the regs. If I ever run a radial its always linear. This one splits from 1 into 3. Old houses I guess but if it complies, that'll do me. Thanks again.

 

[telectrix]

glenn, you are really trying to take the mr. grumpy title from tony. let me know when the head to head comes. :20:

 

[GLENNSPARK]

glenn, you are really trying to take the mr. grumpy title from tony. let me know when the head to head comes. :20:

i`m sick of reading drivvel from them saying their doing board changes etc...who clearly havn`t grasped the basics...
sick of it..

 

[kingeri]

Nothing wrong with branching radials, even the IET is endorsing them with their little pictures in the 17th. Not how I'd wire something from scratch, as it does mean multiple ends to test, but in the case your detailing as long as the circuit tests ok, just use the longest leg as your basis for selecting your OCPD and filling in the paperwork. If it is 2.5mm T&E just check for installation method as this may help you select either a 16 or 20amp MCB/RCBO.

 

[kingeri]

what you going to do?...
hold his hand whilst he does it?...
if he dont know this then he shouldn`t be doing it....

You're probably right Glenn. However, if it's ok with you, I'll respond in the way I see fit, as you seem to be doing tonight.

 

[7029 dave]

ffs give the fella a break its his 1st post!!, be nice!!

 

[AngusSparkie]

Thanks all. Glenn if you read my post I ask if I'm ok to do what everyone else has suggested. I sought clarification as I could not find spider radials in the 17th ed. (I would be grateful for a page no.) and therefore sought clarification that they are ok even if the test results are all fine, which they are. I realise that this was popular in the 70's but that doesn't mean it's current and as I've said I can't find a reference to it in the regs hence my question. I would never wire like this and it wasn't covered on my 17th ed course. Regards.

 

[GLENNSPARK]

You're probably right Glenn. However, if it's ok with you, I'll respond in the way I see fit, as you seem to be doing tonight.

hmm....

 

[kingeri]

hmm....

I was trying to stimulate a conversation about branching radials 'cos I really love 'em.

 

[Marvo]

Hi Angus, Tel's advice was spot on in post#2. You don't need to apologise for seeking clarification on something you're unsure about.

Others who have nothing constructive to say need to walk away without comment.