radial

[theanomally]

How many sockets can be put on 2.5 radial?

 

[markc123]

Unlimited. Within reason though - you're not going to have like 50. You've got to remember you're limited to 20amps, so you as the installer should work out how much is going to be used and make a professional judgement. There is a table in the OSG somewhere, it's late and i'll be honest i can't be bothered to go out to the van and reference from it now

Don't forget it's a 20amp MCB, unless you change to 4mm.

 

[theanomally]

Cool thx

 

[GLENNSPARK]

Unlimited. Within reason though lol.

Don't forget it's a 20amp MCB, unless you change to 4mm.

aye...and you`d be watching your Zs as well with 4.0/1.5mm flat...

 

[markc123]

Good point glenn - i shouldn't have really forgotten that...but its bank holiday, and i'm starting a day drinking session in york in roughly 10hours...forgive me if im a little distracted lol. Yes OP, watch the Zs reading like a hawk

It feels like christmas. Drunk isn't going to be the word

 

[MDJ]

I doony like the OP myself, why ask about the quantity your allowed to add on a 2.5mm2 radial? a better design immediately comes to mind, whats going into the sockets? distance of cable run? whats protecting it? why a radial? why 2.5mm2? why not a ring? what enviroment is the so called "radial" going to be in? how is the cable going to be run, installed or is it already in? lets have more and we can give more.

 

[theanomally]

Purely to see what you can add to an existing 2.5mm radial.I thought there was limits,within reason.Just basically when you are called in to add a Sso somewhere and it's not practicable to run new circuits.Cost,time etc

 

[markc123]

Depends what the existing sockets are being used for, and what the new ones are going to be used for.

The term 'unlimited' is used loosley so that you decide for yourself.

 

[GLENNSPARK]

Depends what the existing sockets are being used for, and what the new ones are going to be used for.

The term 'unlimited' is used loosley so that you decide for yourself.

yes but you also have to assume change of use for points served...
a good reason why initial consutation with the client as to intended use should never be overlooked...

 

[chilliwilly]

Hello folks, Ive just joined the forum and I thought I'd give my tuppence'a'penny about radials. I have recently just started to work for myself again after working as a service engineer for five and half years. Previously before that i had my own electrical contracting business with niccy membership.

In the first niccy snags and solutions book back in the eighties, they stipulated a maximum of 2x twin sockets on a 20 a radial. Despite the 15th edition stipulating an unlimited number covering a maximum floor area of 25 meters. But the guy that I helped back then would just simply spur off a ring as many as he wanted without giving a sh!t!Instead of breaking into the ring or running a new circuit.

After working in the U.S back in the nineties and getting my head around their regs (the National Electrical Code), I discovered that they don't use ring mains but only radials, serving both floors for lights and power on the same circuit. After this experience I eventually stopped using rings over here and decided to adopt their practice of reliabillity and install 20 and 32 amp radials.

In a domestic situation where it is almost impossible to ommit the use of RCDs, I install 2 or more 20 amp radials serving the same rooms on both floors, 2 lighting circuits serving both floors, and a 32 amp radial in a kitchen for sockets. And in most cases have one of the other radials serve the kitchen on the outer areas for for smaller loads. This vastly improves reliabillity and cuts down on the inconvenience of unwanted tripping causing complete power failure on 1 floor. And keeps the job within budget where a split board is used.

In the case following a EICR/PIR, if my customer wants me to carryout the remedial action to neccesitate a board change. Where a departure is found to be excessive non fused spurs, I always encourage them to let me split the ring into 2 radials and leave the spurs as branches, to cut down on damage to decor and keep costs under control. I usually end up with about 8 sockets on each circuit. But in a kitchen more thought to loading has to be considered, in some cases I have installed an extra 20 amp radial using pyro to serve fridges and boilers to ommit the use of RCDs.

As you can gather I do not agree with the over stipulated use of RCDs that we are forced to use or consider, that in my opinion is unneccessary. But that's just me and my meandering better judgement based on experience. And not miss interpretation of regs as I have recently been accused of from another contractor who dare not ommit the use of RCDs. Even within a controlled environment under supervision, or when the 50mm+ rule is applied.

 

[GLENNSPARK]

Hello folks, Ive just joined the forum and I thought I'd give my tuppence'a'penny about radials. I have recently just started to work for myself again after working as a service engineer for five and half years. Previously before that i had my own electrical contracting business with niccy membership.

In the first niccy snags and solutions book back in the eighties, they stipulated a maximum of 2x twin sockets on a 20 a radial. Despite the 15th edition stipulating an unlimited number covering a maximum floor area of 25 meters. But the guy that I helped back then would just simply spur off a ring as many as he wanted without giving a sh!t!Instead of breaking into the ring or running a new circuit.

After working in the U.S back in the nineties and getting my head around their regs (the National Electrical Code), I discovered that they don't use ring mains but only radials, serving both floors for lights and power on the same circuit. After this experience I eventually stopped using rings over here and decided to adopt their practice of reliabillity and install 20 and 32 amp radials.

In a domestic situation where it is almost impossible to ommit the use of RCDs, I install 2 or more 20 amp radials serving the same rooms on both floors, 2 lighting circuits serving both floors, and a 32 amp radial in a kitchen for sockets. And in most cases have one of the other radials serve the kitchen on the outer areas for for smaller loads. This vastly improves reliabillity and cuts down on the inconvenience of unwanted tripping causing complete power failure on 1 floor. And keeps the job within budget where a split board is used.

In the case following a EICR/PIR, if my customer wants me to carryout the remedial action to neccesitate a board change. Where a departure is found to be excessive non fused spurs, I always encourage them to let me split the ring into 2 radials and leave the spurs as branches, to cut down on damage to decor and keep costs under control. I usually end up with about 8 sockets on each circuit. But in a kitchen more thought to loading has to be considered, in some cases I have installed an extra 20 amp radial using pyro to serve fridges and boilers to ommit the use of RCDs.

As you can gather I do not agree with the over stipulated use of RCDs that we are forced to use or consider, that in my opinion is unneccessary. But that's just me and my meandering better judgement based on experience. And not miss interpretation of regs as I have recently been accused of from another contractor who dare not ommit the use of RCDs. Even within a controlled environment under supervision, or when the 50mm+ rule is applied.

bad practice

not good...

not necessarilly...method C?

RCDs...serving points that are to be used by unskilled/uninstructed person/s not under supervision...

the use of RCDs is not cast in stone..
agreed that in most instances the use of RCDs for compliance is a necessity...
but just using radials is going to result in a C/U that may be too large to fit in the space alotted to it

 

[telectrix]

well, i'v ejust managed to stack 48 double sockets on a radial, but when i put the 49th one on, the whole pile coillapsed.

 

[GLENNSPARK]

well, i'v ejust managed to stack 48 double sockets on a radial, but when i put the 49th one on, the whole pile coillapsed.

what? without using `lego bricks`?...well i`m suprised at you Tel....

 

[SJD]

If you check fig 15B in appendix 15 of the BGB, you will see the statement "historically, the floor area served has been limited to 50m2" for a radial with 20A overcurrent protective device and 2.5mm2 live conductors. I read into "historically" that it is not a hard and fast requirement, but as already said, much depends on what will be connected, and would be quite easy to take much more than 20A in a kitchen, for example.

 

[Engineer54]

Hello folks, Ive just joined the forum and I thought I'd give my tuppence'a'penny about radials. I have recently just started to work for myself again after working as a service engineer for five and half years. Previously before that i had my own electrical contracting business with niccy membership.

In the first niccy snags and solutions book back in the eighties, they stipulated a maximum of 2x twin sockets on a 20 a radial. Despite the 15th edition stipulating an unlimited number covering a maximum floor area of 25 meters. But the guy that I helped back then would just simply spur off a ring as many as he wanted without giving a sh!t!Instead of breaking into the ring or running a new circuit.

After working in the U.S back in the nineties and getting my head around their regs (the National Electrical Code), I discovered that they don't use ring mains but only radials, serving both floors for lights and power on the same circuit. After this experience I eventually stopped using rings over here and decided to adopt their practice of reliabillity and install 20 and 32 amp radials.

In a domestic situation where it is almost impossible to ommit the use of RCDs, I install 2 or more 20 amp radials serving the same rooms on both floors, 2 lighting circuits serving both floors, and a 32 amp radial in a kitchen for sockets. And in most cases have one of the other radials serve the kitchen on the outer areas for for smaller loads. This vastly improves reliabillity and cuts down on the inconvenience of unwanted tripping causing complete power failure on 1 floor. And keeps the job within budget where a split board is used.

In the case following a EICR/PIR, if my customer wants me to carryout the remedial action to neccesitate a board change. Where a departure is found to be excessive non fused spurs, I always encourage them to let me split the ring into 2 radials and leave the spurs as branches, to cut down on damage to decor and keep costs under control. I usually end up with about 8 sockets on each circuit. But in a kitchen more thought to loading has to be considered, in some cases I have installed an extra 20 amp radial using pyro to serve fridges and boilers to ommit the use of RCDs.

As you can gather I do not agree with the over stipulated use of RCDs that we are forced to use or consider, that in my opinion is unneccessary. But that's just me and my meandering better judgement based on experience. And not miss interpretation of regs as I have recently been accused of from another contractor who dare not ommit the use of RCDs. Even within a controlled environment under supervision, or when the 50mm+ rule is applied.

I pity the electrician that comes in after you, tracing out lighting circuits and socket circuits running up and downstairs rooms. Never heard of anything so bloody stupid. You must have picked up that little Gem of a system in the States.

It's a good job that our domestics are mostly single phase, or you'll be using the Yank multi branch circuit for lighting and sockets too!! ....lol!!