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Topic Title: 5A Lighting Socket Outlets - RCD protection?
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Created On: 03 April 2013 03:27 PM
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 03 April 2013 03:27 PM
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ThorntonReynolds

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Joined: 03 April 2013

I am working on the electrical fit-out of a new bar/restaurant, within which our Client would like a number of 5A lighting socket outlets for the connection of table lamps and free standing lamps.

Obviously this is a public space and thus general socket outlets shall be RCD (RCBO) protected, but can anyone advise on wherever or not the lighting outlets would best be RCD protected?
Would it make a difference if these were the circular pin type outlets, meaning that only lamps with such a plug could be plugged in?

Many thanks in advance.
 03 April 2013 03:57 PM
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SherlockOhms

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I take it the feed cables are buried in the wall?
 03 April 2013 04:03 PM
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AJJewsbury

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I think you might have a difference of opinion on that one!

As I see it, there's nothing particularly special about 5A sockets - the plugs are still reasonably available and there's nothing really preventing anyone putting one on any kind of appliance, so I'd be tempted to treat them the same as 13A sockets. You do have the option of labelling them as special purpose (reg 411.3.3 (b) - like for freezers) and so justifying 30mA RCD omission on that basis, or indeed, as this is a workplace, if local H&S procedures oblige people to take adequate other precautions, you might be able to justify omitting RCD protection under 411.3.3 (a).

That said, there have been a few fatal accidents involving children and table lamps (neither BC or ES lampholders are entirely touch-proof with the lamp removed), so if its the kind of restaurant that could accommodate children, I'd be inclined to 30mA RCD protect everything within reach anyway.

- Andy.
 03 April 2013 04:47 PM
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Parsley

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Building classification BA2, 30ma RCD's might be a good idea on accessible circuits.

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 03 April 2013 07:40 PM
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dickllewellyn

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Are 5 amp circuits the best solution if its a public restaurant? Would something like a clix plug in rose be better? Ether way, I would be inclined to pop an RCBO in the way, better spend a few quid more on an OPD than stand in front of that bloke in a curly wig and try to remember why you didn't want to include it in my opinion.

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Richard (Dick)

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 04 April 2013 11:05 AM
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OMS

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Start with 411.3.3 (ii) and then work out why you wouldn't want to include an RCD based on 411.3.3 (a) or (b).

Look at the definition of socket outlet in Part 2

Also look at 553.1 et seq in relation to BS 546 plug and socket assemblies

All of tha lot should tell you that you would omit RCD protection at your peril for this kind of application - if you include RCD protection then obviously your design also needs to consider 314.1 and 531.2.4 along with 53.2.9 (if applicable).

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OMS

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 04 April 2013 09:32 PM
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statter

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Statement of the obvious but don't forget that 5A plugs don't have sleeved pins so shock hazard is greater ....another reason for RCD here
 05 April 2013 11:42 AM
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Angram

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2amp 3pin plugs have regulation sleeving.

Might be a better choice if available easily.

I think 150watts each is still the figure for circuit design.
 05 April 2013 11:52 AM
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AJJewsbury

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Some makes of 5A plugs have sleeved pins too - http://www.screwfix.com/p/crab...-round-pin-plug/93850
- Andy.
 05 April 2013 10:53 PM
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statter

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Interesting does the BS specify where the contact with the pin should be made? I f not isn't there a risk of a poor connection if plugs and sockets from different manufacturers are used?
 09 April 2013 02:29 PM
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AJJewsbury

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It's a fair question - I understand that early plug/socket standards didn't define which side should have the "springiness" - so some manufacturers had spring contacts in the socket and solid pins on the plug, while others had solid contacts in the sockets and 'split-pin' plugs. Mixed one way around and it was decidedly unsatisfactory!

In this case though, I'm not sure what the BS says but given the thickness of the frontplate (and any shutter mechanism), I'd be surprised if the socket contacts where close to the base of the plug.

- Andy.
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