13amp sockets on lighting circuits.

[ericmark]

If it needs a tool to use the 13 amp socket then nothing is going to stop some one plugging into it,

don't need a 13 amp socket to be able to plug into lights.

 

[sparkwright]

Yes it is. Someone, somewhere has clearly not thought about it. Why would anyone with more than 2 brain cells explicitly permit an arrangement that can overload the circuit with one plugged in appliance?

I seem to recall your disgust at a 13 amp switched FCU above a kitchen worktop controlling a single 13 amp socket with a washing machine plugged into it.

You didn't like the idea of two 13 amp fuses. (Nothing wrong with it I might add.)

Now your solution to this was to replace that 13 amp single socket for a 15 amp socket with 15 amp unfused plug.

So there is a 13 amp switched FCU controlling a 15 amp socket.

So by doing that, you created exactly the same situation where a larger load can potentially be plugged into a smaller rated circuit.

What's the difference?

 

[winston1]

Surely the solution is to replace the fcu with a double pole switch.

But with a 15A socket on a fcu the main difference is that there nothing else on that circuit. No one will be plunged into darkness.

 

[sparkwright]

(The idea was for the 13 amp fuse to be accessible easily without dragging out the appliance.)

But a single socket on a lighting circuit, labelled or even engraved, with something like 'lighting only' or 'maximum 3/5 amps' should reasonably ensure no one is going to be plunged into darkness, wouldn't it?

For what it's worth, I avoid 13 amp sockets on lighting circuits if I can - though occasionally it's unavoidable: such as when I have run supplies from the lighting circuit to serve kitchen plinth lighting, only to discover the customer has bought plinth lights with a wall wart on them. What do you do? Mess about finding another 'transformer' or whatever you like to call it - or fit a labelled 13 amp socket behind the plinth, fit the plinth, and try to forget about it. Can't worry about everything.

 

[JohnW2]

... Alarm bells rang in our heads when they counted the 13A sockets and then started discussing who had what extention leads and double adapters. .... This was for a hairdressing competition with plans for 80 stations/competitors. There were a little more than 20 double sockets across 3x 32A circuits and they were planning to use a double adapter in each socket and a domestic extention lead to each station. .... We joined in the conversation and asked what was likely to be used - a 2KW hair dryer and hair straighteners/curling tongs each. .... As I say it is their responsibility to investigate properly, that's what H&S RAMS are all about.

Hmmm. I think you have probably moved the goalposts right out of the stadium, if not farther

These discussions are generally about the installation of one 13A socket on a lighting circuit in a loft of a standard domestic dwelling, and the risk of someone one day plugging in some load which might conceivably be 2-3kW. You appear to be talking about something far divorced from a 'standard domestic dwelling' and a potential total load of at least 160 kW (if all the hairdryers were used simultaneously).

Kind Regards, John

 

[JohnW2]

Yes it is. Someone, somewhere has clearly not thought about it. Why would anyone with more than 2 brain cells explicitly permit an arrangement that can overload the circuit with one plugged in appliance?

Maybe the same person who permits an arrangement (a 16A or 20A radial) that can overload the circuit with just two appliances plugged into two of the umpteen outlets?

 

[SUNRAY]

Surely the solution is to replace the fcu with a double pole switch.

But with a 15A socket on a fcu the main difference is that there nothing else on that circuit. No one will be plunged into darkness.

Ah but you haven't described all of the problems with the circuit. Whereby legitimate loads on fused outlets, whether they be plugs or FCU's makes a housefull of appliances/devices suddenly stop working. Oh dear a circuit design that it is clearly wrong. How long it will be before it is changed in the regs I don’t know.

Read more: https://www.diynot.com/diy/threads/13amp-sockets-on-lighting-circuits.578527/page-2#ixzz785qLF6Li

 

[SUNRAY]

Hmmm. I think you have probably moved the goalposts right out of the stadium, if not farther

These discussions are generally about the installation of one 13A socket on a lighting circuit in a loft of a standard domestic dwelling, and the risk of someone one day plugging in some load which might conceivably be 2-3kW. You appear to be talking about something far divorced from a 'standard domestic dwelling' and a potential total load of at least 160 kW (if all the hairdryers were used simultaneously).

Kind Regards, John

I was simply describing the folly of not investigating circuits before use.

As it happens we got the job to provide temporary power. We were able to pinch the feeds to 3 ovens in the kitchen, they are known to be 125A 3ph supplies (although fused down local to the ovens), we haitually install metering on temporaries and each 3ph supply peaked at something like 90-100KW IIRC so a potential peak in the room of 270-300KW. This was in the summer...

 

[plugwash]

I was simply describing the folly of not investigating circuits before use.

It sounds like you were describing a group that were in over their heads and had absoloutely no concept of how much power stuff used.

But still I don't think it's reasonable for someone to investigate circuits before plugging in a single domestic appliance.

As it happens we got the job to provide temporary power.

Glad to hear they saw sense.

This was in the summer...

Toasty, hopefully it wasn't for too long.

 

[bernardgreen]

But with a 15A socket on a fcu the main difference is that there nothing else on that circuit. No one will be plunged into darkness.

So from where does the supply to the FCU come from ? "nothing else on that circuit" suggests that the FCU is the only item fed from an MCB in the consumer unit.

 

[winston1]

(The idea was for the 13 amp fuse to be accessible easily without dragging out the appliance.)

Why? If the oven has caused the fuse to blow (where ever it is) it needs to be dragged out anyway for investigation/repair.

 

[winston1]

So from where does the supply to the FCU come from ? "nothing else on that circuit" suggests that the FCU is the only item fed from an MCB in the consumer unit.

Should have said "nothing else on the fcu".

 

[winston1]

But a single socket on a lighting circuit, labelled or even engraved, with something like 'lighting only' or 'maximum 3/5 amps' should reasonably ensure no one is going to be plunged into darkness, wouldn't it?

Labels fade, drop off, are ignored. People don't understand how much load an appliance takes.

 

[bernardgreen]

Should have said "nothing else on the fcu".

That suggests you believe the fuse wire in the FCU will get hot enough to melt before the magnetic trip in the MCB operates.

In past you have said that FCUs are not needed

""" You don't need the FCU. FCU's are not required or used on lighting circuits. A 3a fuse in a FCU will have no discrimination against a 6a MCB in your CU. A loft is a stupid place to have a FCU. """

Read more: https://www.diynot.com/diy/threads/fcu-spur-off-lighting-circuit.503814/#ixzz787nGp6Fk

 

[JohnW2]

I was simply describing the folly of not investigating circuits before use.

I realise that, but it was in such a different ballpark from what we are discussing as to not be very relevant.

One would hope that if a group of ~80 people were discussing their need to plug in 80 x 2kW loads into an electrical installation that they would have the sense to 'investigate' (seek advice) as regards what was possible.

However, even a person with a lot of sense and intelligence would probably not have any reason to think that there was any need to 'investigate' or 'seek advice' about plugging a vacuum cleaner into a 13A socket in a loft, any more than they would if they were going to plug it into 13A socket anywhere else in the house.

There is a big, big difference between those scenarios!

Kind Regards, John