Situtation is a new, small garage (16 sq m) fed from the house via a 16A mcb and 30mA main RCD. I am doing my own installation under a Building Notice to the local council building control dept.
Plans filed with the application are for a garage unit with 1 x 6A mcb for lighting, and 1 x 16A mcb for 2 double and 1 single sockets and a spur box for the garage door actuator, but I did not show any detail of the power circuit topology.
As the wiring comes at this CU from 3 different directions (left, right and below) I have brought 3 separate 2.5 mm^2 tails into it, one each from the two double sockets and one from the single socket via the spur box. The terminals of the breaker will accept 3 tails without a problem.
Since the cable (in trunking) is rated at over 20A and this circuit is protected by two 16A breakers in series I consider the requirements for protecting the cables against overload and short circuit are met. However the electrical contractors to whom the local authority have sub-contracted the inspection say this arrangement breaks some rule about radial circuits, though they cannot tell me which rule nor why the arrrangment is not safe.
Their recommendation is to daisy chain all four fittings, by using crimped connections in the CU to run additional wires out to each double socket and back. This will put 10m of cable and four additional intermediate connections between the breaker and the furthest outlet, which clearly makes no sense from the point of view of either reliability or fault clearance time or voltage drop.
Can anyone on this forum give me a definitive ruling either way as to whether what I originally proposed is allowed?
TIA
Plans filed with the application are for a garage unit with 1 x 6A mcb for lighting, and 1 x 16A mcb for 2 double and 1 single sockets and a spur box for the garage door actuator, but I did not show any detail of the power circuit topology.
As the wiring comes at this CU from 3 different directions (left, right and below) I have brought 3 separate 2.5 mm^2 tails into it, one each from the two double sockets and one from the single socket via the spur box. The terminals of the breaker will accept 3 tails without a problem.
Since the cable (in trunking) is rated at over 20A and this circuit is protected by two 16A breakers in series I consider the requirements for protecting the cables against overload and short circuit are met. However the electrical contractors to whom the local authority have sub-contracted the inspection say this arrangement breaks some rule about radial circuits, though they cannot tell me which rule nor why the arrrangment is not safe.
Their recommendation is to daisy chain all four fittings, by using crimped connections in the CU to run additional wires out to each double socket and back. This will put 10m of cable and four additional intermediate connections between the breaker and the furthest outlet, which clearly makes no sense from the point of view of either reliability or fault clearance time or voltage drop.
Can anyone on this forum give me a definitive ruling either way as to whether what I originally proposed is allowed?
TIA