Sockets on a lighting circuit - C3 or C2?

Dartlec · Aug 24, 2022

Fun EICR at an HMO today, which was installed new 5 years ago (not particularly well!)

Lots of niggly things that I'll sort, but in the kitchen cupboards were two unswitched sockets which confused me for a while.

Turns out they are connected to the lighting circuit, switched by their own switch by the door - apparently originally for pelmet lighting that was never installed.

[ElectriciansForums.net] Sockets on a lighting circuit - C3 or C2?

I'll likely blank them off anyway, but was thinking about how I'd code it and swinging between a C2 and a C3.

Everything is RCD protected, so that's not an issue. 6A breaker should trip fast enough to avoid any long term overload of the cable (1.5mm)

In purely terms of actual or potential danger, where would others put it? It's clearly bad workmanship and something that should never have been installed 5 years ago, and there's an argument for putting C2 just to ensure it gets changed, but that's rather against the spirit of the codes - Is there enough potential danger to reach a C2..

Dustydazzler · Aug 24, 2022

Seen quite a few new builds in recent years with a 13amp socket on a 6a breaker for the boiler to be plugged into

loz2754 · Aug 24, 2022

As there is no immediate danger, nor any potential danger, it doesn't warrant a code.
Maybe just a note.

westward10 · Aug 25, 2022

I see no issue at all there is nothing to say you cannot fit a 13A socket on a lighting circuit, it isn't bad workmanship and there is no potential danger.

littlespark · Aug 25, 2022

Agreed. It’s not “general” power.

Some of these pelmet lights come with plugs attached… designed to be plugged in.
Not easily accessible location… no different to a socket in attic for tv amp taking from lights.

You could label it, I suppose.

Pretty Mouth · Aug 25, 2022

No code, 559.5.1(v). A label would be nice though.

pc1966 · Aug 25, 2022

Here it probably has no danger.

But if it could be mistaken for a normal power outlet and so trip out all lights at night due to someone plugging in a heater then I would argue it had a danger to it.

UNG · Aug 25, 2022

This is one of those problems that isn't helped by the lighting manufacturers who supply power supplies and LED drivers that come as a 13A plugin units for their low voltage lighting, it is one of those evils of poor design that doesn't have many if any options to avoid

pc1966 said:
But if it could be mistaken for a normal power outlet and so trip out all lights at night due to someone plugging in a heater then I would argue it had a danger to it.

It could be argued that connecting outside lighting to an indoor lighting circuit could trip out all the lighting if water gets into an outside light should that be considered a danger

DPG · Aug 25, 2022

I had a 13A socket in my loft for years for powering an aerial amplifier and saw no issue with that at all. However I did put a dymo label on it to indicate that it was fed from the lighting circuit.

As UNG says, it's not always possible to put a 5A socket on for lighting these days because of the plug-in transformers.

pc1966 · Aug 25, 2022

UNG said:
This is one of those problems that isn't helped by the lighting manufacturers who supply power supplies and LED drivers that come as a 13A plugin units for their low voltage lighting, it is one of those evils of poor design that doesn't have many if any options to avoid

Very true.

UNG said:
It could be argued that connecting outside lighting to an indoor lighting circuit could trip out all the lighting if water gets into an outside light should that be considered a danger

Ideally they would be separate circuits.

But there is also a big difference between that where it is a possible fault-condition that trips the lights, and a 13A socket inviting usage of items well above the 6A limit such as heaters, vacuum cleaners, etc.

OK here it is not in such a location that would be likely, but that was my earlier point about the accessibility of such a socket impacting its risk. Had it been a 5A socket then no issue as clearly not normal use-case and if used in-design then 5A is available.

Dustydazzler · Aug 25, 2022

As above tv amp in loft often plugged into a single 13am ssocket feed nicked from a light , have even done this for low watt shower pumps in the loft space

Sometimes I have put a 13am socket ontop of kicthen cupboards for the under unit lights to plug starighnt into feed / swicthed off the light switch set up

as mentioned seen quite a few boilers on a 13am plug off a 6am mcb

in America they have quite a few mixed 16 and 10am mixed circuits with sockets ( receptacles ) and lights all on the same ting

pc1966 · Aug 25, 2022

Dustydazzler said:
As above tv amp in loft often plugged into a single 13am ssocket feed nicked from a light , have even done this for low watt shower pumps in the loft space

Sometimes I have put a 13am socket ontop of kicthen cupboards for the under unit lights to plug starighnt into feed / swicthed off the light switch set up

To me those are fine as special use out of the normal locations you would expect to see a socket, and in most cases will have the load permanently plugged in.

Dustydazzler said:
as mentioned seen quite a few boilers on a 13am plug off a 6am mcb

Odd, I would have used a FCU, but if clearly marked for the boiler in its cupboard space then no issue.

Dustydazzler said:
in America they have quite a few mixed 16 and 10am mixed circuits with sockets ( receptacles ) and lights all on the same ting

Yes, they have some odd practices over there.

pc1966 · Aug 25, 2022

Dustydazzler said:
as mentioned seen quite a few boilers on a 13am plug off a 6am mcb

Any idea why the 6A MCB, were they wired in 1mm (a technical no-no until AM2 for power circuit)?

I would have just gone 16A 1.5mm radial and then a 3A of 5A fuse on the FCU or 13A plug for the actual load.

Dustydazzler · Aug 25, 2022

pc1966 said:
Any idea why the 6A MCB, were they wired in 1mm (a technical no-no until AM2 for power circuit)?

I would have just gone 16A 1.5mm radial and then a 3A of 5A fuse on the FCU or 13A plug for the actual load.

seen them wires in all sorts , 1mm , 1.5 and 2.5

probably what ever the contractor had to hand

pc1966 · Aug 25, 2022

Dustydazzler said:
seen them wires in all sorts , 1mm , 1.5 and 2.5

probably what ever the contractor had to hand

To be fair, I would probably have used 2.5mm just because I generally only have 1mm lights or 2.5mm for RFC/small radial lying around...

Dustydazzler · Aug 25, 2022

pc1966 said:
To be fair, I would probably have used 2.5mm just because I generally only have 1mm lights or 2.5mm for RFC/small radial lying around...

I know a lot of new build sparks wiring a lot of power stuff in 1.5 at the momnet due to the high cost of cable

pc1966 · Aug 25, 2022

Dustydazzler said:
I know a lot of new build sparks wiring a lot of power stuff in 1.5 at the momnet due to the high cost of cable

With appropriate OCPD to match?

Dustydazzler · Aug 25, 2022

pc1966 said:
With appropriate OCPD to match?

16am cicruit with 1.5 cable for wall panel heaters , boilers , water heaters , towel rails etc
anything where you can get away with using 1.5 to save money

Rockingit · Aug 25, 2022

I really don't see an issue here. Just because something is unconventional doesn't make it unsafe. The circuit is protected by suitable OCPD, the components are rated => the maximum design current.... there's simply nothing to code. Arguments of "what if....." could be applied to an infinite number of scenarios which is why we don't inspect on what doesn't exist.

Lister1987 · Aug 25, 2022

C3 just to show you have seen it and educated the client. Doesnt fail the install but covers you if anything occurs

Intoelectrics · Aug 25, 2022

pc1966 said:
Here it probably has no danger.

But if it could be mistaken for a normal power outlet and so trip out all lights at night due to someone plugging in a heater then I would argue it had a danger to it.

I would argue its an inconvenience rather than a danger. Yes we can all imagine scenarios where the sudden loss of lighting could cause an issue. But we can do the same for many scenarios (as previously stated) Provided the OCPD is correct for the circuit design I believe its fine. I have done this myself previously, especially if the client wanted the flexibility.

As mentioned perhaps a label would suffice?

Rockingit · Aug 25, 2022

Lister1987 said:
C3 just to show you have seen it and educated the client. Doesnt fail the install but covers you if anything occurs

Rubbish. On what engineering basis does it require and justify an improvement?

Intoelectrics · Aug 25, 2022

Lister1987 said:
C3 just to show you have seen it and educated the client. Doesnt fail the install but covers you if anything occurs

What improvement would you recommend other than a label? You could swap them out to FCU's or blank them off but are these an improvement?
I'm not criticising I'm just asking, thinking out loud so to speak.

UNG · Aug 25, 2022

Lister1987 said:
C3 just to show you have seen it and educated the client. Doesnt fail the install but covers you if anything occurs

You can make an observation it does not have to have a code attached to it

UNG · Aug 25, 2022

Intoelectrics said:
What improvement would you recommend other than a label? You could swap them out to FCU's or blank them off but are these an improvement?
I'm not criticising I'm just asking, thinking out loud so to speak.

To continue the circle if you swap them for FCU's how would you plug in a 13A plugin lighting adapter that most manufacturers supply these days