Hows it comply with 433.1.1?IANDoesnt have to be a ring, rings av nawt to do wiy it
"standard circuits"
like wiseI assume from the lack of regs supporting its compliance that no one can back up their claims?
no point.I assume from the lack of regs supporting its compliance that no one can back up their claims?
please add your input after all this is a good discussion thread. we all learnA poll has been started, any comments about why you voted should be posted here, and not via the poll.I have my own views about compliance on this subject that has not so far been mentioned.
Hi Manator,I will be more than happy to do so.When you design any circuit, you will eventually have to include any alteration to that circuit, that could cause a problem.
So if we take this example, we know that whilst its two seperate 2.5mm cables and the end protection is provided by FSU, we have no control on any additions.
You could theoretically end up with two double socket outlets, or spurs off the said radials.
Good practice would prevent any designed circuit to become dangerous or unstable, so both 2.5mm could have been designed far better and still provide protection if the designer had limited its potential use.
The end result could be that a 2.5mm radial protected by a 32amp mcb, could be used to supply a full circuit it is not designed to do.
Its not what we put into the design, its what others will take out of it.
I personally would not design a circuit with two 2.5mm sharing a 32 amp mcb, regardless of how the end protection is acheived, unless I had full control over any alterations to the installation.
I do not think anyone has mentioned any additional alterations, which is what I based my initial comment on.
We have to assume that any alteration from any circuit is carried out by a competant person, the example you give would counter my argument I agree.Hi Manator,The exact same argument could be used against a spur off a ring final - we can't really design with a view to alterations people might make in the future
So by this reckoning any circuit containing a socket or a spur is suitably protected against overload by fuses in the appliance plugs or FCU's?? If this was a single 2.5mm radial circuit rather than 2 would we protect it like that? because it amounts to the same thing - RCBO gives fault protection, upstream fuse gives overload protection. Don't forget that to blow that upstream fuse the overload current must first make its way through the 2.5mm to get there.this has nothing to do with a ring. the fact is, the cable is protected against fault current by RCBO. its protected against overload by SFCU. it does not contravene any regs. the design is fully compliant with 7671
I have made another poll which covers the (in my view) key piece of information from the original post that Badger's poll misses. :innocenthave made a poll in the poll section
Yours misses the point too.I have made another poll which covers the (in my view) key piece of information from the original post that Badger's poll misses. :innocent
Enter your email address to join: