Spur help?

[wildm]

In one of my upstairs rooms I have 3 double sockets. This is not a ring but a radial circuit. The curcuit is fed from a 16Amp breaker on the consumer unit (installed by an electrician last year - I say 16Amp as it is labelled as B16...)????

There is a spur running from a junction box on this radial circuit to the loft (1 x double socket).

Is this OK or should this spur be from a ring circuit or on its own seperate radial????

I need to understand whether I need to do something or whether it is safe. The loft socket is only used sparingy as the loft is just used for storage.

 

[pda]

it is perfectly safe the total number of spurs should not exceed the total number of socket outlets (unless fused spurs fitted) as long as the 16amp socket outlets comply with BS 4343 and the maximum demand is known not to exceed the rating of the overcurrent device which in ur case is 16amp

 

[wildm]

Thanks.

I wasn't sure as everything I have read talks about spurs running off a ring circuit - not a radial. That is why I wanted confirmation.

 

[andy]

it is perfectly safe the total number of spurs should not exceed the total number of socket outlets (unless fused spurs fitted) as long as the 16amp socket outlets comply with BS 4343 and the maximum demand is known not to exceed the rating of the overcurrent device which in ur case is 16amp

he says the radial has double sockets protected by a B16 MCB. he makes no reference to BS4343.

wildm - providing the cable going to the spur in the loft is the same CSA used to the radial (should be 2.5mm) then there is nothing wrong with what you have. you can take spurs from both ring and radial circuits. the number of unfused spurs (which is what you have) must not exceed the number of sockets on the circuit. there can be an unlimited number of fused spurs

 

[wildm]

Thanks - I am reassured now.

The majority is 2.5mm but there is some original wiring (advised this is lead wiring) between two sockets. I am going to relace this with 2.5mm

The BS4343 has cmpletely confused me though. I have searched and anything Ican see related to BS4343 do not look like standard double sockets as used in the home. The consumer unit is new and was fitted by qualified electrician etc in the last few months so I would expect everything to comply with the latest regs?

 

[andy]

Thanks - I am reassured now.

The majority is 2.5mm but there is some original wiring (advised this is lead wiring) between two sockets. I am going to relace this with 2.5mm

The BS4343 has cmpletely confused me though. I have searched and anything Ican see related to BS4343 do not look like standard double sockets as used in the home. The consumer unit is new and was fitted by qualified electrician etc in the last few months so I would expect everything to comply with the latest regs?

BS4343 are the 16A industrial sockets (the yellow type used on 110V equipment, blue for 230V and red for 3 phase).

 

[plugwash]

BS4343 has nothing to do with the original question (its a standard for industrial socket outlets)

and the spur rules are for rings not radials

i start to smell a b**********

 

[wildm]

So the BS434 comment is irrelevant then? I am talking about wiring in the home....

I don't understand why the BS4343 was mentioned???

 

[andy]

So the BS434 comment is irrelevant then? I am talking about wiring in the home....

I don't understand why the BS4343 was mentioned???

BS4343 is irrelevant. i have no idea why it was brought up.

 

[andy]

and the spur rules are for rings not radials

so what are the rules for spurs on a radial?

 

[wildm]

Seen the reply on BS434 - thanks. To be honest I know the rules on spurs not exceeding existing sockets etc.

I now have 1 person saying I can run a spur from a radial and one saying I can't. As i said everything I have seen only talks of spurs from a ring main not a radial. If someone could help me out on this that would be great.

If not I suspect that I am going to have to run the loft double socket as a spur from a ring.

 

[plugwash]

there isn't really any such thing as a spur on a radial cuircuit just branches.

and just like on a lighting cuircuit you can branch however you like on radial socket cuircuits

rings are a special case allowed by the regs where you can use a lower rated cable than the breaker size provided you use a ring of cable back to the CU and you follow thier special spur rules.

 

[wildm]

Ah, I see.

So it is really just the terminology here. Spurs v branch.

You knew what I meant so it looks fine. I always suspected it was but as all the floorboards are up etc now is a good time to sort everything out.

Thanks

 

[Damocles]

Now we have established that there are no problems about spurring off a 16A circuit wired in 2.5mm cable, what was that bit about lead?

Did you mean cables with an outer sheath made of lead, or with silver coloured conductors inside? If lead sheathed, then it might need attention. Very old. If the conductors are silver coloured then they are copper coated with tin. Quite old. But if PVC insulated then fine provided the conductors are the correct size.

 

[Adam_151]

But if he has got the floorboards up, he may as well replace it (the lead cable) with new 2.5mm T&E then there is no question about is it ok or not