Ring from a radial ?

[KEVINDOE]

Hi Guys,

Changing a c/u today, i have discovered that the existing 6mm t+e , originaly for cooker supply , now has a 2.5mm ring final connected into the existing cooker connection unit, there are three , two gang sockets connected to this , has anyone come across this before, ? looks like the kitchen fitters work to me, any thoughts ?

Thanks Jem

 

[Electricalserv]

Hi Guys,

Changing a c/u today, i have discovered that the existing 6mm t+e , originaly for cooker supply , now has a 2.5mm ring final connected into the existing cooker connection unit, there are three , two gang sockets connected to this , has anyone come across this before, ? looks like the kitchen fitters work to me, any thoughts ?

Thanks Jem

Nope never had that before, sounds like a DIY job. Is there any paperwork? Old test results etc???

 

[KEVINDOE]

Hi elec,
no paperwork, owner just moved in, kitchen is five years old,...i would like to fuse it at 32amp as oven (13amp),, and two other two gang sockets are on this ring

 

[IQ Electrical]

What's the rating of the protective device ?

It's commonly referred to as a 'lollipop' circuit, normally found where RCD protection has been added to a ring by way of a stand-alone RCD in an enclosure.

The 6mm feeds the RCD, the ring being connected to the outgoing side.

Unconventional but If the OPD is 32A or less and the connections are accessible then it's just an issue of bad practice in my opinion.

 

[Des 56]

Its not seen that much,but there is little wrong with the arrangement
The 6 mm on a 32 amp mcb is ok
The circuit can be tested as a ring + radial, as long as there is indication of the circuit arrangement on the certificate

 

[telectrix]

it's just as if the cooker isolator is a sub main. OCD of 32A, as long as tests confirm circuit/s are OK, note on cert. i assume the 6mm is RCD protected. if not bung in a RCBO.

 

[KEVINDOE]

Thanks I.Q,

The box im replacing is a 6 way 3036, new one will be 17th , split load with 30 m/a R.C.D protection, all connections are accessible, so i am hoping to protect at 32amp, all cabling good , loop is .39, Ze is .12 (PME), I.R. is >299 all round.
Should i note it on E.I.C ?

Jem

 

[telectrix]

note it just so as it is seen that the ring final is supplied via cooker isolator. one advantage is that , in the case of a fault, the kitchen sockets have local isolation.

 

[Chr!s]

Not sure any note need be made as such.

You could class the 6mm as a distribution circuit, providing theres no connections en route.

The cooker connection unit is now the origin of the circuit.

Overload is omitted as per 433.3.1

And fault current 434.2.2

 

[Sintra]

The only part of the regs that would contradict this set up is in appendix 15 were it states.

"A ring final circuit starts and finishes at the distribution board, where it is connected to a 30A or 32A overcurrent protective device."


Sent from my iPhone using Tapatalk.

 

[Chr!s]

The only part of the regs that would contradict this set up is in appendix 15 were it states.

"A ring final circuit starts and finishes at the distribution board, where it is connected to a 30A or 32A overcurrent protective device."

Well appendix 15 is informative only, and what im saying is the cooker control switch is now the DB, and the overcurrent requirements have been omitted from that point in accordance with 433.3.1 and 434.2.2

 

[Des 56]

The only part of the regs that would contradict this set up is in appendix 15 were it states.

"A ring final circuit starts and finishes at the distribution board, where it is connected to a 30A or 32A overcurrent protective device."

.

Agreed, a standard ring circuit should start and finishes at the board
The circuit in question is not standard,the best description was IQs A Lollipop
Being a non standard circuit,if it ticks all the boxes it is acceptable

 

[Chr!s]

Agreed, a standard ring circuit should start and finishes at the board
The circuit in question is not standard,the best description was IQs A Lollipop
Being a non standard circuit,if it ticks all the boxes it is acceptable

Whats stopping the 6mm from being a distribution circuit?

By definition a distribution board is fed via a distribution circuit.

Look at the definition of a distribution board?

So if we omit overcurrent from the DB as per the regs already stated, the ring starts and finishes at the DB, or by definition a sigle point of supply.

 

[Chr!s]

Or if you dont like that approach, then its a non standard circuit called the lollipop, providing it meets the requirements of BS7671 then wheres the problem, BS 7671 allows us to design non standard circuits.

 

[Des 56]

Or if you dont like that approach, then its a non standard circuit called the lollipop, providing it meets the requirements of BS7671 then wheres the problem, BS 7671 allows us to design non standard circuits.

I am not dis agreeing Chris
On the contrary I see no problem whatsoever with the arrangement, as I posted previously