Garage wiring question.

[nobbynomates]

Recently moved into a "new to us" house, have a question about the wiring in the garage.
The garage is built onto the side of the house, it has its own dedicated ring final, which has 3 double sockets, however, it also has 2 junction boxes in the ring final that supplies power to the 2 strip lights.
The junction boxes are both accessible as they are fixed to the wall, all the cable used is 2.5mm, clipped onto the wall, and comes from the CU in the house on its own 16a rcd.
Is this all ok to you?

 

[delmel]

simple answer is not done correctly and not correct protection.

 

[ericmark]

It is permitted to use 16 amp protection for lighting circuits but normally one would fuse to 5A. (There may be 3A fuses inside the strip lights)
It is considered bad practice to have lights and sockets on the same protective device but it does not break rules.
It is not normal to use a ring final system with protection under 30A but again there is nothing to stop you.
Today it would need RCD protection but there is no requirement to update existing systems.

So I do not see anywhere that rules are broken but also would say not the ideal method of wiring.

 

[PrenticeBoyofDerry]

Recently moved into a "new to us" house, have a question about the wiring in the garage.
The garage is built onto the side of the house, it has its own dedicated ring final, which has 3 double sockets, however, it also has 2 junction boxes in the ring final that supplies power to the 2 strip lights.
The junction boxes are both accessible as they are fixed to the wall, all the cable used is 2.5mm, clipped onto the wall, and comes from the CU in the house on its own 16a rcd.
Is this all ok to you?

It is not conventional to spur a circuit for lights directly from a socket circuit, I doubt the socket circuit is a ring if protected by a 16A device? Possibly a radial!
If the cable is 2.5mm T&E that can in most cases carry in excess of 16A, so the cable is safe in most cases on a 16A device, so what you have is safe in most cases. There are derating factors to consider in the routing and containment of cables, that can reduce the cable current carrying capacity, so that would require further investigation. However it is common practise to down-fuse the cables, load side of lighting.

 

[nobbynomates]

Thanks all, PrenticeboyofDerry, it`s definately a ring final circuit.

So whats the best way of improving/making good?

How do you down-fuse the cables, load side of lighting?

 

[securespark]

Fit an FCU where the spur branches off the ring final to the lighting.

However, how are the lights switched?

 

[PrenticeBoyofDerry]

delete duplicated post, not my doing!

 

[PrenticeBoyofDerry]

Thanks all, PrenticeboyofDerry, it`s definately a ring final circuit.

So whats the best way of improving/making good?

How do you down-fuse the cables, load side of lighting?

Just out of interest, how have you come to the conclusion that it is a ring final circuit, did you start with end to end continuity tests of all conductors, then r1+r2 tests?

To down fuse you will require a FCU (fused connection unit) and a 3A fuse to replace the manufacturer's factor fitted 13A one.
The FCU, should be installed where the the socket circuit has been broke in to prior to the light switch/light. So the the 3A fuse, then protects the lighting side of the circuit. If you have two points that have been broke in to, then two FCUs are required.

 

[ban-all-sheds]

Just out of interest, how have you come to the conclusion that it is a ring final circuit, did you start with end to end continuity tests of all conductors, then r1+r2 tests?

And did you think about why someone would install a ring final using a 16A breaker?

 

[nobbynomates]

Just out of interest, how have you come to the conclusion that it is a ring final circuit, did you start with end to end continuity tests of all conductors, then r1+r2 tests?

PrenticeboyofDerry, Visually, i can see the whole cable run.


And did you think about why someone would install a ring final using a 16A breaker?

Bas, i`ve no idea, perhaps you could enlighten me?

 

[ban-all-sheds]

Ignorance? Incompetence?

 

[JohnW2]

Just out of interest, how have you come to the conclusion that it is a ring final circuit, did you start with end to end continuity tests of all conductors, then r1+r2 tests?

PrenticeboyofDerry, Visually, i can see the whole cable run.

And did you think about why someone would install a ring final using a 16A breaker?

Bas, i`ve no idea, perhaps you could enlighten me?

Ignorance? Incompetence?

Indeed. A good few people seem to believe that all sockets circuits have to be rings (some even think that lighting circuits should be rings) - so, if such a person only wants/needs a 16A circuit, they are likely to end up installing a 16A ring! Of course, there's nothing wrong with it, electrically - but it involves an unnecessary bit of cable!

Kind Regards, John

 

[ban-all-sheds]

True, but we should not ignore the waving red flags and loud alarm bells ringing which tell us that at some point someone ignorant and incompetent has been fiddling with the electrical installation.

 

[JohnW2]

True, but we should not ignore the waving red flags and loud alarm bells ringing which tell us that at some point someone ignorant and incompetent has been fiddling with the electrical installation.

True, although that "we" and "us" probably should have been "I" and "me".

That red flag waves over almost all properties, (hopefully) other than pretty new ones - so one always has to be aware of the possibility that "someone ignorant and incompetent may have been fiddling with the electrical installation", even if one has not (yet) seen any evidence of that.

In this particular case, it is obviously of far less concern (no concern at all, per se,) that someone has unnecessarily wired a 16A 2.5mm² sockets circuit as a ring than it would be if they had failed to wire a 32A 2.5mm² sockets circuit as a ring.

Kind Regards, John

 

[ban-all-sheds]

one always has to be aware of the possibility that "someone ignorant and incompetent may have been fiddling with the electrical installation", even if one has not (yet) seen any evidence of that.

True, but when convincing evidence is found.....

In this particular case, it is obviously of far less concern (no concern at all, per se,) that someone has unnecessarily wired a 16A 2.5mm² sockets circuit as a ring than it would be if they had failed to wire a 32A 2.5mm² sockets circuit as a ring.

In this particular case there's no safety concern, but it does create the very real concern that someone who didn't understand what he was doing has been installing new circuits, and someone like that could just as easily have done something dangerous.