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Topic Title: Hand Dryer Install
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Created On: 21 May 2013 10:33 AM
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 21 May 2013 10:33 AM
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Grayston

Posts: 21
Joined: 12 December 2012

I've been asked to fit hand dryers in an office toilet and thought i'd check.
I was going to fuse spur off the ring final for each, as long as the ring has RCD protection.
If not would it be a new radial from the CU.
also as there's no bath or shower is the 0.6m zone 2 distance still required, I was going to do this if possible.
Cheers
G
 21 May 2013 11:35 AM
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AJJewsbury

Posts: 11699
Joined: 13 August 2003

According to BS 7671, if there's no bath or shower then there isn't any zone 2 (or zone 1 or any other zone) as section 701 doesn't apply. (And despite what some DIY stores might tell you, BS 7671 has no requirement for a zone 2 around hand basins even in bathrooms). As there's no socket and provided you're not concealing soft-skinned cables in the wall, then there's no demand for 30mA RCD additional protection either.

There's a general requirement for equipment to be suitable for the conditions - there's nothing specific, but a comparison might be guidance for kitchens where the usual recommendation for wall plate accessories is a minimum 300mm horizontally from the sink/drainer.

- Andy.
 21 May 2013 12:33 PM
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anastasis

Posts: 586
Joined: 01 September 2009

If the RFC feeds computers, as is likely in an office, and it has an RCD, would you want the risk of a nuisance trip? In these circumstances, I think most businesses would happily pay the extra for a new circuit.

There is also the question of capacity on the RFC, and the guidance that fixed loads of 2kw upwards should have dedicated circuits. But given the duty cycle of your typical hand dryers, it would strike me as a fairly pointless discussion... Having said that, people in offices sometimes bring in portable heaters in winter, and overloaded circuits are not unknown.
 21 May 2013 10:20 PM
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SKElectrical

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RCD isn't required for commercial use. Think I would pull in a new ring, in case they ask for more than one. Don't install crap dryers, they are a total waste. Decent dryers cost about £200 upwards.
 22 May 2013 11:31 AM
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Grayston

Posts: 21
Joined: 12 December 2012

Thanks for the advice guys, was edging towards a new ring, but dont think the customer will go for the quote, they wanted me to "just connected them to the light switch" that was a no comment type of answer!
 22 May 2013 03:45 PM
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ebee

Posts: 5781
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How many hand dryers (assuming 2KW each?) ?
Why a ring? (I`ve nothing against rings) .
What about one leg becoming disconnected?

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 22 May 2013 03:57 PM
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Grumpy

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Grayston sounds like a young chap, why would his leg fall off?
 22 May 2013 04:28 PM
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Grayston

Posts: 21
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I meant radial, 3 at 1.8kw so a 20A radial should be ok.
 22 May 2013 09:36 PM
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leckie

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2x1.8 is more than 20A.

Edit:
Sorry, I meant 3x1.8 is more than 20A, typo.

Edited: 23 May 2013 at 06:31 AM by leckie
 23 May 2013 02:54 AM
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SKElectrical

Posts: 910
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Originally posted by: leckie

2x1.8 is more than 20A.


No.





Originally posted by: Grayston

I meant radial, 3 at 1.8kw so a 20A radial should be ok.


I cannot stress enough how much more effective it is to have one decent dryer than 5 which have no blow to them.
 23 May 2013 09:25 AM
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anastasis

Posts: 586
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Originally posted by: SKElectrical
I cannot stress enough how much more effective it is to have one decent dryer than 5 which have no blow to them.


I couldn't agree more. A client of mine had a load of el-cheapo wholesaler's own brand ones fitted during a large refurb (I think they were only about 1.5kW), despite the design and specification being done by a firm of consultants who should have known better. They produced so little hot air that everyone complained and we got to replace them a few years later

I did some research into the best options and found the 2.5kW ones sold by TLC (amongst others) worked well and are reasonably priced (around £100+VAT). They've been well-received. We had a couple of demos of "high-efficiency" dryers but the clients didn't like them, mainly because they were expensive and sounded like a 747 taking off.

To quote a famous phrase, you can't change the laws of physics. The volume and temp of the air out is directly related to the power in. You will be disappointed by the performance of low-powered ones.
 23 May 2013 12:28 PM
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Grayston

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sorry your correct, 22.5amps, dam it 4mm then.
 24 May 2013 05:33 AM
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ebee

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Well if you count them as space heaters , which essentially they are, then yes 22.5 amps at 240V .
But to consider short lengths of on time and realistic diversity, I don`t think a 20 amp circuit would actually worry many.

Having said that, the previous posts suggest greatly higher rated units would gain you extra brownie points with the clients wheras the 1.8 units might lose you future work.

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
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