Interested in your thoughts....

[Adam W]

lol!! ...Enough said then!! Your problem, ...not mine!!

Post #1 suggests differently.

 

[Engineer54]

Post #1 suggests differently.

Explain yourself then, ...cause everyone loves a smart arse!!

 

[netblindpaul]

BTW E54, I did not post my conclusions, because I would have come up basically with your points, obviously bar the knowledge of the actual specs of the job.
A lollipop is "acceptable" but confusing.
I would not install one on a new install, but, I would be tempted to mod an install to one, if cost was a significant factor.
BTW why rings not radials?
Is it a load distribution/volt drop thing?
If so you had better ensure that the rings are wired "every other" as it were!

 

[Engineer54]

BTW E54, I did not post my conclusions, because I would have come up basically with your points, obviously bar the knowledge of the actual specs of the job.
A lollipop is "acceptable" but confusing.
I would not install one on a new install, but, I would be tempted to mod an install to one, if cost was a significant factor.
BTW why rings not radials?
Is it a load distribution/volt drop thing?
If so you had better ensure that the rings are wired "every other" as it were!

It's a pretty long service counter Paul, with more than just a few appliances being supplied. And yes, all ring circuits are wired in a ''staggered'' configuration on this project, that's one thing i always lay down at the very begining of a project, i don't accept long runs back to the DB/CU. I prefer to see radials on circuits where loads can be moved about, rather than loading them up on a permanent/semi permanent basis, if you know what i mean. ...lol!!

 

[Adam W]

Explain yourself then, ...cause everyone loves a smart arse!!

Your thread, your problem.

I was only trying to help by contributing to it, eg suggesting you shouldn't reduce the csa of a cable over 3m without a protective device, as per BS7671.

Sorry if that came across as being "smart".

 

[Engineer54]

Your thread, your problem.

I was only trying to help by contributing to it, eg suggesting you shouldn't reduce the csa of a cable over 3m without a protective device, as per BS7671.

Sorry if that came across as being "smart".

Even when the cables sizes are fully protected by the supplying protective device??

I don't think so... There is nothing electrically wrong with lollipop arrangement, it's just not what you would expect or be appropriate in a new installation.

If you explained your remarks a little better, it wouldn't have been taken as being Smart!!

 

[malcolmsanford]

I think you would need to identify if the 6mm "lollipop" was a sub main or part of the RFC

543.2.9 Except where the circuit protective conductor is formed by a metal covering or enclosure containing all of the conductors of the ring, the circuit protective conductor of every ring final circuit shall also be run in the form of a ring having both ends connected to the earthing terminal at the origin of the circuit.

So I suppose mate that if the ring starts at the junction box it would comply, but if the RFC starts at the CU then it does not comply.

Bottom line as you say mate it is just really not a good way to have a circuit IMO

 

[Engineer54]

I think you would need to identify if the 6mm "lollipop" was a sub main or part of the RFC

543.2.9 Except where the circuit protective conductor is formed by a metal covering or enclosure containing all of the conductors of the ring, the circuit protective conductor of every ring final circuit shall also be run in the form of a ring having both ends connected to the earthing terminal at the origin of the circuit.
So I suppose mate that if the ring starts at the junction box it would comply, but if the RFC starts at the CU then it does not comply.

Bottom line as you say mate it is just really not a good way to have a circuit IMO

Agree Malc, i've seen plenty of these circuits over the years, and all have been confusing when first encountered. ...But one things for sure, you don't need a protective device in this instance at the transition point, when all else, electrically complies.

 

[malcolmsanford]

I suppose by the letter of the regs you should as your reduction in CSA will exceed 3 metres, but has the protection is just 32amps for the entire circuit and your using 6mm radial and 4mm for the RFC then I would only be fitting the one OPD at the origin.

Reg 434.2.1 IMO is aimed a circuit where you have a 63amp Ring Main in 10mm and you want to tap off for <3 metre in say a 6mm for something.

 

[Engineer54]

I suppose by the letter of the regs you should as your reduction in CSA will exceed 3 metres, but has the protection is just 32amps for the entire circuit and your using 6mm radial and 4mm for the RFC then I would only be fitting the one OPD at the origin.

Reg 434.2.1 IMO is aimed a circuit where you have a 63amp Ring Main in 10mm and you want to tap off for <3 metre in say a 6mm for something.

Exactly Malc, ....The 3 metre rule was never meant for cables that were still being fully protected by the OPD at the origin of the circuit!!

 

[johnboy6083]

Street lighting circuits would never comply if that wasnt the case.

 

[Adam W]

Well you have 2 options:

• Wire the cct as a FLC
• Do it properly.

It's up to you which one you choose, but I would go for the second option.
That's my thought on the matter, take it or leave it.

 

[Engineer54]

Well you have 2 options:

• Wire the cct as a FLC
• Do it properly.

It's up to you which one you choose, but I would go for the second option.
That's my thought on the matter, take it or leave it.

Read post #25!!!

Funnily enough, I really don't need you telling me how to ''Do it properly''.

 

[Adam W]

I suppose by the letter of the regs you should as your reduction in CSA will exceed 3 metres, but has the protection is just 32amps for the entire circuit and your using 6mm radial and 4mm for the RFC then I would only be fitting the one OPD at the origin.

Reg 434.2.1 IMO is aimed a circuit where you have a 63amp Ring Main in 10mm and you want to tap off for <3 metre in say a 6mm for something.

IMO it relates more commonly to the reduction in CSA of a pendant wired in 0.5mm flex from a 1mm or 1.5mm lighting circuit, but either way in this situation there should be a protective device at the reduction in CSA where the ring 'lollypops' off, making the SWA a submain. The ring would then begin at this point, in line with convention.

 

[Adam W]

Read post #25!!!

Funnily enough, I really don't need you telling me how to ''Do it properly''.

Read what you entitled the thread.