(Debate) Using 1.5mm wire for external double socket:

[mainline]

Hi all,

I've got a 1.5mm wire running from the consumer unit to the outside which was previously a light. I've done away with the lights and want to repurpose the wire for a couple of plug in cameras.

Appendix 15 of BS 7671:2018 says it is acceptable to use a 1.5mm cable for a socket as long as there is a fused spur first as the cable can handle up to 15 amps and the spur will limit it to 13A anyway.

However, my question is;

As this cable goes straight from the CU, with no other lights or demand, does it still need a fused spur or can it go directly without one?

Many thanks!

If this is a socket which is outside, then it should be RCD protected.

 

[SPECIAL LOCATION]

If this is a socket which is outside, then it should be RCD protected.

If this is a socket inside it would also need RCD protection anyway!

 

[mainline]

If this is a socket inside it would also need RCD protection anyway!

Yes, but the OP is on about putting one outside.
Your post #4 suggested that an MCB would be fine.

 

[7029 Dave]

IMO a radial circuit suppling socket should be on a 16A minimum with the 2.5mm cable.
The only 1.5mm cable I would be happy to use for this application is MICC.
Having said that all suggestions mentioned are not incorrect but IMO the circuit design is very poor.
6A protection for such a circuit COME ON.

 

[Andy™]

IMO a radial circuit suppling socket should be on a 16A minimum with the 2.5mm cable.

how you would/wouldnt do it is irrelevant. what matters is does it comply with BS7671

 

[7029 Dave]

how you would/wouldnt do it is irrelevant. what matters is does it comply with BS7671

So electrical craft principles means nothing to you, which we were all taught at college?.
Its not all about BS7671 its about standard working practices.

 

[Andy™]

So electrical craft principles means nothing to you, which we were all taught at college?.
Its not all about BS7671 its about standard working practices.

guess you're the type who would give an unsatisfactory EICR to an installation that's fully compliant with BS7671 but not done to your standards / opinion...

1.5 feeding a socket. is it the way most of us would do it? no. is it compliant? yes. so what's the issue?

 

[7029 Dave]

guess you're the type who would give an unsatisfactory EICR to an installation that's fully compliant with BS7671 but not done to your standards / opinion...

1.5 feeding a socket. is it the way most of us would do it? no. is it compliant? yes. so what's the issue?

It has nothing to do with my standards or option, its how I've been taught out in the field and technical
college. Your answer is very confusing you say you would not do it so you must also have an issue designing such a circuit. Why are you throwing in EICR? With 46 years experience in the industry I can honestly say I'm more than competent in that area.

 

[Andy™]

i wouldnt do it that way, but that doesn't mean its wrong

 

[binky]

IMO a radial circuit suppling socket should be on a 16A minimum with the 2.5mm cable.
The only 1.5mm cable I would be happy to use for this application is MICC.
Having said that all suggestions mentioned are not incorrect but IMO the circuit design is very poor.
6A protection for such a circuit COME ON.

Doesn't matter, how many sockets have been installed in attics tapped into light circuits to power a TV booster?. What matters is that the cable is protected from overload.

I have moved the "debate" here, away from DIY. Please feel free to continue.

 

[SPECIAL LOCATION]

IMO a radial circuit suppling socket should be on a 16A minimum with the 2.5mm cable.
The only 1.5mm cable I would be happy to use for this application is MICC.
Having said that all suggestions mentioned are not incorrect but IMO the circuit design is very poor.
6A protection for such a circuit COME ON.

So electrical craft principles means nothing to you, which we were all taught at college?.
Its not all about BS7671 its about standard working practices.

It has nothing to do with my standards or option, its how I've been taught out in the field and technical
college. Your answer is very confusing you say you would not do it so you must also have an issue designing such a circuit. Why are you throwing in EICR? With 46 years experience in the industry I can honestly say I'm more than competent in that area.

Possibly your craft principles were different to many other industry recognised standards? (also taught going back over many many years?)

e.g. basic design where you have a known load, was to select an overcurrent protective device sufficient to supply the load, and an appropriate cable type and size suitable for the rating of the protective device, allowing for derating correction factors, installation methods and volt-drop... etc..

Then after that comes the business economics element where there is no point over-engineering a solution that is more expensive when a cheaper solution can meet all of the electrical and safety elements of the design.

Hence why back in the days of the old regional electricity boards.. (I am in the midlands and ours was the "MEB")...
When their engineers came and installed economy7 night storage heaters, you often got a 3kW storage heater, off a 13A FCU, (or 20A DP switch), fed by a 1.5mm T&E connected to a 15A 3036 wire fuse in the old Wylex fusebox!
Which is no worse than had it been single 13A socket.... ?

However back to the OPs actual question..
He wants a socket to plug in a "CAMERA" (guessing its a plug-in transformer jobbie)..
It is NOT a socket for general purpose... No kettles/toasters/tumble driers etc..

I am struggling to understand why you would consider it is required to have a 2.5mm 16A supply for a Camera PSU that could probably run off a USB socket from a laptop??