does this comply?

[ianmacd]

Quite right it could easily sit on a 20A, i wasnt as suggesting it had to be on a 32A but i could see it not complying either. Im glad people are discussing the point i raised and quoting regs and not just criticizing me, i asked if it complied, i didnt say this is the best designed circuit ever.

And it clearly is not as clear cut as some was suggesting...

Sorry Wozzie but I think it is. Its not a ring, its a radial and as such it can not be protected by a 32A breaker and comply.

Yes there are situations where you could use the remote fuse but its not ideal. I would be looking at a 16A (or even a 20A if it really needs to be) or if thats not enough for both branches then split them up.

 

[kme]

+1

 

[Nicky Tesla]

Now then Wozz, i know exactly were u are coming from. That reg has always seemed contrary to me. People are saying "its a radial, not a ring", so wot! A radial off a ring is a radial. Whatever rules apply to the radial off the ring will apply to the radial off the mcb, electrically what is the difference, nothing!!!

Eg what if a ring was created at two sockets directly below the DB in fact the pattress touches the DB they are that close, but still they create a ring. Then from this ring, take your two radials. Electrically, what exactly is the difference? None so whats the point? no need for the ring.

So what is stopping wozz putting in a 63a mcb? the cable will still have overload protection from the plug fuse. So in the BRB example, why is 32a acceptable? and what else will be?

what we need is to analyse the differences in the 2 scenarios, and not just say it is bad practice. If it is then why is is not bad practice from a ring? :C

 

[Lee321]

clearly then as the opinion is split across respected members we'll have to put it in the no definate answer bin Guinness

 

[wozz]

exactly nicky. When i was thinking about it i drew a ring circuit with a spur from the origin going to one point. As far as im aware this complies. You remove the ring circuit and suddenly it doesnt? ?:|

 

[Lee321]

wozz as has been said

some think and me its legit by brb

however we'd not practice it.

change the scenario a little again someone has said it would you do it with a 200a mcb?

if not why not?

 

[Nicky Tesla]

instinct says it will be wrong, but why?

Its not a ring....its bad practice.....its not 3Metre......its not a 20a mcb....

all clutching at straws......come on, can someone put their finger on it?

 

[wozz]

[quote name='Lee

 

[sparkytim]

BRB PG 362 & 363 Appendix 15

And how about number of spurs should not exceed the number of points ON a ring ?

 

[Lee321]

BRB PG 362 & 363 Appendix 15And how about number of spurs should not exceed the number of points ON a ring ?

well tim ROTFWL the first statement from brb says A RADIAL starts and finishes at the db :_|

 

[steptoe]

IMHO, and I know many of you dont give a stuff for it, the spur off a ring with downstream protection was intended as I said before for alarms etc to utilise, not for a circuit to be designed to.

its still a 2.5mm radial protected by a 32A MCB.

isn't there somehow you could link the 2 outlets and make it a ring?

or even at that point, just link one of the outlets to the other cable and then simply have 1 spur,

get it within a reasonable distance of the 2nd outlet and you comply.

your other, 3rd, option, is to note it as a deviation and define why/how you have kept the circuit safe.

PPP=PPP

would apply in this case,

I know you didnt design or plan the circuit, but whoever did needs shot with a ball of their own dung.

 

[sparkytim]

[quote name='Lee

 

[Nicky Tesla]

so is there a length max to these spurs in the BRB, wozz could be fitting 2 alarms to his spurs for all we know.

 

[steptoe]

then he could downgrade to a 6a MCB

 

[Nicky Tesla]

but is there a need, not in your previous example

 

[steptoe]

but is there a need, not in your previous example

if it is two radials ,? yes,

if he can make it into a ring incorporating at least one of his points with the other a reasonably acceptable spur, no.

 

[wozz]

IMHO, and I know many of you dont give a stuff for it, the spur off a ring with downstream protection was intended as I said before for alarms etc to utilise, not for a circuit to be designed to.its still a 2.5mm radial protected by a 32A MCB.

isn't there somehow you could link the 2 outlets and make it a ring?

or even at that point, just link one of the outlets to the other cable and then simply have 1 spur,

get it within a reasonable distance of the 2nd outlet and you comply.

your other, 3rd, option, is to note it as a deviation and define why/how you have kept the circuit safe.

PPP=PPP

would apply in this case,

I know you didnt design or plan the circuit, but whoever did needs shot with a ball of their own dung.

i know how to design the circuit to make it comply in a way everyone would recognise i just could see the problem with it being done that way. I will look up what sparkytim said but fear these both relate to ring circuits which wasnt the point, I was using the unfused spur on a ring as a example of when the reg allow for this situation.

433.3.1 (ii) is what i wanted clarification on and other peoples thoughts on.

 

[Nicky Tesla]

if it is two radials ,? yes,if he can make it into a ring incorporating at least one of his points with the other a reasonably acceptable spur, no.

we are not looking at this as an actual situation steps, and make the cct into a ring if possible. This is what most of us would do in reality i expect cos it is such a confusing area. We just need to know why it is acceptable in only some occasions.

 

[steptoe]

we are not looking at this as an actual situation steps, and make the cct into a ring if possible. This is what most of us would do in reality i expect cos it is such a confusing area. We just need to know why it is acceptable in only some occasions.

in all honesty, its probably one of those things that falls into a judgement call.

personally I would downgrade to a 25a MCB at largest, maybe even a 20 would do as has been stated, and if Zs can take it try using even a 25C or a 20C, both will hold well over their rated current for quite some time, and what would the chances of both appliances calling for full load at the same time be?

if a 25a MCB wont hold in then I think perhaps there are other issues here,

Im not convinced both appliances are on the threshold of using 13a and both at exactly the same time.

 

[steptoe]

we are not looking at this as an actual situation steps, and make the cct into a ring if possible. This is what most of us would do in reality i expect cos it is such a confusing area. We just need to know why it is acceptable in only some occasions.

right, I answered that as a de-facto

in theory,

you have a cable designed for 27amps max protected by a device rated at 32amps,

and this circuit has been designed in that manner,

that is why I am saying it is in non compliance.

if you have a ring final circuit designed to carry 32amps, and then take a 2m(example) spur off it to a 13a outlet, then that 2m of cable can carry that current as it is designed in that manner.

as you well be aware, I am not an advocate of the ring system for many reasons, one of which is highlighted in this scenario, we have a cable designed to carry at max 27amps but in some circumstances(rings) we allow it to carry 32amps.

I know it doesnt seem right, but that is the regs, if you wish to abide by them.