Is it OK to run 2 radial circuits from one space in the fuse box?
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Can I run 2 radial circuits from one space in the fuse box?
- Thread starter Stefanplant
- Start date
No, however you can have a radial thats 'branched' at the CU, you have to decide whether you need two radials or just one, if its two bedrooms, then one 16A radial would most likely be enough for example, if however its one bedroom and one water heater, then you'll most certainly need two
Well it would become just one radial that branched at the fuseway.
As always you have to consider cable rating and load. Using a breaker rated higher than the cable is frowned upon (though not nessacerally unsafe depeding on the exact design) so putting two runs on one breaker effectively limits the total load of those runs to the rating of one of them.
also there is a regulation about minimisation of inconviniance from trips. i'd interpret this to mean that you shouldn't double up unless lack of space, breaker availibility etc forces you to.
As always you have to consider cable rating and load. Using a breaker rated higher than the cable is frowned upon (though not nessacerally unsafe depeding on the exact design) so putting two runs on one breaker effectively limits the total load of those runs to the rating of one of them.
also there is a regulation about minimisation of inconviniance from trips. i'd interpret this to mean that you shouldn't double up unless lack of space, breaker availibility etc forces you to.
314-01-04
I kind of see your point Fezzie but if both radials supply different parts of the ground floor and the MCB is labelled 'Downstairs Sockets' then this particular reg is satisfied!
If they (the two radials) serve different types of circuit (eg one leg to sockets, the other to fixed appliance) then you MAY have a problem with 314-01-01. This is where opinion comes in as these sort of loads are often spurred off of ring finals!.
If it is two radials for the same area then in practice you would be better off linking the radials to form a ring, therefore being able to uprate the MCB and get more loading on the circuit!
If they (the two radials) serve different types of circuit (eg one leg to sockets, the other to fixed appliance) then you MAY have a problem with 314-01-01. This is where opinion comes in as these sort of loads are often spurred off of ring finals!.
If it is two radials for the same area then in practice you would be better off linking the radials to form a ring, therefore being able to uprate the MCB and get more loading on the circuit!
By definition in "the regs" each circuit must have its own fuseway.
This point has been discussed many times.
If it is one circuit then 1 fuseway.
If it is two circuits then 2 fuseways.
However you may branch.
If you branch then what is difference between branching at a point or branching at the fuseway? much like spurring off a ring final may be at any point or between points or at circuit origin (at the fuseway).
So it depends on your intention as to whether your radial(s) are 1 circuit or 2 circuits . Which is somewhat laughable, plus it makes I & T a bit of a beggar sometimes.
An easier question is - "Is our Parson`s budgie a bird of Pray?"
This point has been discussed many times.
If it is one circuit then 1 fuseway.
If it is two circuits then 2 fuseways.
However you may branch.
If you branch then what is difference between branching at a point or branching at the fuseway? much like spurring off a ring final may be at any point or between points or at circuit origin (at the fuseway).
So it depends on your intention as to whether your radial(s) are 1 circuit or 2 circuits . Which is somewhat laughable, plus it makes I & T a bit of a beggar sometimes.
An easier question is - "Is our Parson`s budgie a bird of Pray?"
To expand on what ebee has said, if you have two rooms, each 30m² and each fed with a 2.5mm² mm² radial, connect them to separate fuses, all well and good, you have two circuits, you can't have two circuits on one fuse, so if you connect both cables to the same fuse, you have one circuit, not two, so in my 30m² rooms example, on one fuse, because its only one circuit, you have one non-compliant circuit (max floor area of 50m² exceeded), not two compliant ones as you would have if you used separate fuseways
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