TV in bathroom - regs and safety

[ban-all-sheds]

As I said there is never, ever, reason to put a 13 amp socket on a lighting circuit

Wrong.

Again.

What we don't need to do is encourage it with unsuitable sockets on a circuit primarily designed for lighting.

559.5.1 Connection to the fixed wiring

At each fixed lighting point one of the following shall be used for the termination of the wiring system:

(i) A ceiling rose to BS 67

(ii) A luminaire supporting coupler to BS 6972 or BS 7001

(iii) A batten lampholder or a pendant set to BS EN 60598

(iv) A luminaire to BS EN 60598

(v) A suitable socket-outlet to BS 1363-2, BS 546 or BS EN 60309-2

(vi) A plug-in lighting distribution unit to BS 5733

(vii) A connection unit to BS 1363-4

(viii) Appropriate terminals enclosed in a box complying with the relevant part of BS EN 60670 series or BS 4662

(ix) A device for connecting a luminaire (DCL) outlet according to BS IEC 61995-1

(x) An installation coupler BS EN 61535.

 

[winston1]

I didn't say it was not allowed. I said there was never, ever, a reason to do it. All houses have power circuits so there is no reason to use the lighting circuits for 13 amp sockets, ever.

 

[mwatsonxx]

I didn't say it was not allowed. I said there was never, ever, a reason to do it. All houses have power circuits so there is no reason to use the lighting circuits for 13 amp sockets, ever.

Simplest and widest used method of supply to a cooker hood.

 

[JohnW2]

Clear labels can be removed/fall off.

One can go a long way to making that very unlikely.

The idea of plugs and sockets is that they can easily be removed.

In normal usage, yes, but that is not inevitably the case. I have some plugs in my house which have not been removed from their sockets in years.

I presume that most of your objections can be overcome by connecting a (non-lighting) load to a 'lighting circuit' via fixed wiring to an FCU (rather than a plug/socket) - although maybe you'll hypothesise that someone could then change the fuse in the FCU to a 13A one and hard-wire an immersion heater to it! However, that may not be convenient and, in any event, the common issue is with a 'wall wart' which necessarily has to be plugged into a BS1363 socket.

As for your fear that (despite labels and/or measures to prevent easy removal of the plug) someone will one day plug in a large load which causes a 6A MCB to operate and 'plunge the house into darkness', I do wonder what sort of loads you are thinking about. I can think of very few portable appliances with plugs that draw more than 1.5kW - 2kW (about 6.5A - 8.5A), and even they are usually only used for brief periods of time. A current of 8.5A would take at least 30 minutes to cause a B6 to operate and a current of 6.5A would not cause a B6 to ever operate, even if continuous. What appliances did you have in mind, particularly ones likely to be used for long periods in lofts (which is the common scenario discussed)?

Also, as I've previously written, if people want (for whatever reason) to connect BS1363 socket(s) to a 'lighting circuit', if the cable were installed by Method C (or some other Methods in the case of 1.5mm² cable), would you be happy if they simply changed the B6 MCB to a B16 one??

Kind Regards, John

 

[winston1]

Simplest and widest used method of supply to a cooker hood.

Source?

Why it the simplest? If you are going to spur off a circuit above only a "cowboy" would choose the lighting circuit.

All the cooker hoods I have seen are either plugged into a 13 amp socket on the kitchen ring or via a FCU also on the kitchen ring.

 

[JohnW2]

Regarding 20 amp radials, why pick on them? Any circuit can be overloaded ...

Because, as you say, almost any circuit with sockets can be overloaded and, in my opinion, it is less likely that someone will plug a large load into a dedicated socket for something on a 'lighting circuit' (despite labelling telling them not to) than it is that people (maybe different people) will plug in loads totalling >20A into a 20A radial circuit with, say, a dozen socket outlets, maybe in different rooms.

This whole issue exists because, many decades after it ceased to have any billing implications, we persist in making a distinction between 'lighting' and 'power' circuits and, worse, for some reason have developed a tradition/habit of protecting 'lighting' circuits with a 5A/6A OPD, despite the fact that the cables are very commonly good for at least 16A.

Kind Regards, John

 

[mwatsonxx]

Source?
Why it the simplest? If you are going to spur off a circuit above only a "cowboy" would choose the lighting circuit.

Any properly trained electrician. If you need a supply near the top of the wall best to take it from above, if practical.

All the cooker hoods I have seen are either plugged into a 13 amp socket on the kitchen ring or via a FCU also on the kitchen ring.

I've only ever seen them connected to the lighting circuit via a 13A s/o

 

[winston1]

I presume that most of your objections can be overcome by connecting a (non-lighting) load to a 'lighting circuit' via fixed wiring to an FCU (rather than a plug/socket).

NO. FCUs are not needed or used on lighting circuits. A 5 amp fuse has no discrimination against a 6 amp MCB, and probably a 3 amp won't have either. There is no objection to using a 2 or 5 amp BS 546 socket however.

As for your fear that (despite labels and/or measures to prevent easy removal of the plug) someone will one day plug in a large load which causes a 6A MCB to operate and 'plunge the house into darkness', I do wonder what sort of loads you are thinking about. I can think of very few portable appliances with plugs that draw more than 1.5kW - 2kW (about 6.5A - 8.5A), and even they are usually only used for brief periods of time. A current of 8.5A would take at least 30 minutes to cause a B6 to operate and a current of 6.5A would not cause a B6 to ever operate, even if continuous. What appliances did you have in mind, particularly ones likely to be used for long periods in lofts (which is the common scenario discussed)?

A kettle would certainly do it. In fact I once witnessed that happen when someone plugged a kettle into a garage socket that was on a lighting circuit.

In a loft on a cold winters day imagine someone plugging a fan heater into a lighting circuit that was already loaded with several 5 foot flourescent fittings illuminating said loft. Then having to find their way to the dodgy ladder in darkness without putting their foot through the floor.

Also, as I've previously written, if people want (for whatever reason) to connect BS1363 socket(s) to a 'lighting circuit', if the cable were installed by Method C (or some other Methods in the case of 1.5mm² cable), would you be happy if they simply changed the B6 MCB to a B16 one??

As I'm sure you know you can't just go round changing MCBs. Other things have to be taken into consideration. For instance most ceiling long roses and light switches are rated at a lot less than 16 amps.

 

[winston1]

Any properly trained electrician. If you need a supply near the top of the wall best to take it from above, if practical.

Indeed, and and above (under the upstairs floor) he/she will find power circuit wiring.

 

[JohnW2]

NO. FCUs are not needed or used on lighting circuits. A 5 amp fuse has no discrimination against a 6 amp MCB, and probably a 3 amp won't have either.

Agreed. I should not have talked of FCUs but, rather, of JBs or 'outlet plates'. What I was really asking was whether you were happy with (suitably small) non-lighting loads being hard-wired to a 'lighting circuit'. Are you? The problem, of course is, as I said, that people often want to connect 'wall-warts', and they do not allow for any means of connection other than a BS1363 socket.

A kettle would certainly do it.

Even if it were a 3kW kettle (and none of mine are), it would have to be a pretty slow kettle to trip a B6, and if it was a 2kW one it would take 30 mins or more to cause a trip - which therefore wouldn't happen.

In a loft on a cold winters day imagine someone plugging a fan heater into a lighting circuit ....

Conceivable, but only if they ignored the labelling etc. In any event, fan heaters are usually no more than 2kW - so, again, should give them at least 30 mins.

As I'm sure you know you can't just go round changing MCBs. Other things have to be taken into consideration. For instance most ceiling long roses and light switches are rated at a lot less than 16 amps.

Does that mean that you actually don't believe that the OPD is there "only to protect the cable"??

Kind Regards, John

 

[winston1]

Agreed. I should not have talked of FCUs but, rather, of JBs or 'outlet plates'. What I was really asking was whether you were happy with (suitably small) non-lighting loads being hard-wired to a 'lighting circuit'. Are you? The problem, of course is, as I said, that people often want to connect 'wall-warts', and they do not allow for any means of connection other than a BS1363 socket.

Outlet plates or even clock connectors should be OK. Wall warts are a problem with two solutions.
1. Replace it with a power supply with wire ends.
2. Fit a 13 amp socket but not one wired into the lighting circuit.

Even if it were a 3kW kettle (and none of mine are), it would have to be a pretty slow kettle to trip a B6, and if it was a 2kW one it would take 30 mins or more to cause a trip - which therefore wouldn't happen.
Conceivable, but only if they ignored the labelling etc. In any event, fan heaters are usually no more than 2kW - so, again, should give them at least 30 mins.

This assumes there are no other loads on the circuit. These days there could be loads of 50 watt downlights on taking 2 to 3 amps.

Does that mean that you actually don't believe that the OPD is there "only to protect the cable"??

That's an interesting one. This statement is usually quoted in respect of BS1362 fuses in plugs an FCUs rather than fixed wiring accessories. But clearly a switch rated at say 6 amps should not be used on a circuit protected at 16 amps.

 

[ban-all-sheds]

I didn't say it was not allowed. I said there was never, ever, a reason to do it.

What we don't need to do is encourage it with unsuitable sockets ....

Here is the list of devices considered suitable for use as fixed lighting points:

• A ceiling rose to BS 67
• A luminaire supporting coupler to BS 6972 or BS 7001
• A batten lampholder or a pendant set to BS EN 60598
• A luminaire to BS EN 60598
• A suitable socket-outlet to BS 1363-2, BS 546 or BS EN 60309-2
• A plug-in lighting distribution unit to BS 5733
• A connection unit to BS 1363-4
• Appropriate terminals enclosed in a box complying with the relevant part of BS EN 60670 series or BS 4662
• A device for connecting a luminaire (DCL) outlet according to BS IEC 61995-1
• An installation coupler BS EN 61535.

 

[winston1]

I didn't say it was not allowed. I said there was never, ever, a reason to do it.

 

[JohnW2]

Outlet plates or even clock connectors should be OK. Wall warts are a problem with two solutions. ... 1. Replace it with a power supply with wire ends. ... 2. Fit a 13 amp socket but not one wired into the lighting circuit.

(1) could often be a problem. Wall warts are commonly not just generic, but, rather, come with teh equipment in question. Many people would have problems (and quite probably would make mistakes) in selecting a suitable replacement 'with wire ends', and I suspect that, for what it's worth, so doing would probably also invalidate the equipment's warranty (in this case, possibly with good reason). There is, of course, a third option - which is what is being discussed here!

That's an interesting one. This statement is usually quoted in respect of BS1362 fuses in plugs an FCUs rather than fixed wiring accessories.

Not in my experience. It is a statement very commonly made in relation to fixed wiring. Indeed, most of what gets discussed here is related to BS7671, and what happens downstream of a BS1363 plug is outwith the scope of that.

But clearly a switch rated at say 6 amps should not be used on a circuit protected at 16 amps.

Before one could comment sensibly on that statement, one would need to know a lot more about what the 'rating' referred to - and that is far from obvious. In practice, no standard light switch is going to be asked to carry or break anything approaching 6A, but the implication of the rating is that it could. It's all but impossible to imagine how a lighting load (which was normally sensible) could develop a fault which resulted in an overload situation - and, as for fault currents, they will 'be what they are' (potentially hundreds of amps) regardless of the rating of the circuit's OPD. ... and as for things like ceiling roses being 'rated at 6A', that is almost laughable - and, again, a current that would never pass through a rose other than in 'fault current' conditions (in which case the current would be dramatically greater than 6A).

Kind Regards, John

 

[stillp]

I didn't say it was not allowed. I said there was never, ever, a reason to do it.

My loft has no socket circuits in it, but it does have a lighting circuit. How do you think I should power my aerial amplifier?

(Clue: a suitably labelled 13A socket-outlet)