I've been asked to add a USB charging port into a bedroom with a bath in it.
My understanding of BS7671 is that a room with a bath is a bathroom. As such the outlet would be in zone 2 of the bath.
Would I need to power the charger via a safety transformer and could this be built into a +IP4 enclosure similar to a shaver outlet
Thanks for your assistance
I have to be honest, I still cant see how a floating voltage between + & - so close together offers any risk given that pin to pin must sill be the shortest and lowest resistance path. I dont understand why the electrons would go the lone way round and even into the wet human body even at only 500ohms resistance that achieves enough to reach let go levels let alone death.
Electricity in water doesn't behave in the way you'd expect.
There are people who have died from hairdryer, heated curling appliance, or shaver on charge falling into the bath they were in (not in the UK) ... you'd have thought the mains would take the short path between the L and N pins, but even if it did, the 'parallel path' through the body only needs to conduct a relatively small current for things to be fatal. These things do happen.
In the UK we've had a relatively good record with the prohibition on socket-outlets close to a bath that have been in place for a very long time.
I would be supplying to a contractor who is supplying to the prime contractor who is fitting it to hotels. Any warning would need to be added to the front plate in all languages (person in bath crossed through icon?).
A good point.
I have found USB C IPX4 connectors that I can fit ti a plate or grid.
I've been pondering that.... presumably a type with a cover of some kind - so the IP rating is only maintained when the socket isn't in use? (or possibly requires a matching IP rated plug, which users are unlikely to use).
Shouldn't we interpreting 701.512.2 as requiring the IP rating to be maintained at all material times - not just when it's not in use?
- Andy.
Can we clarify the use of Energy Source Classes 1, 2 and 3 for hazard levels of voltages and currents and the standards not discussing SELV, PELV, ELV and LV
If we need the USB socket to be SELV but the usual USB converters don't say they provide SELV - could we achieve the same be creating a simple 12V SELV circuit (using a conventional isolating transformer if needs be), convert to d.c. and then use a 12V powered USB module (of the type usually used in caravans or vehicles - e.g. https://www.12voltplanet.co.uk/cbe-21a-double-usb-charger-grey.html) - I can't see that the module would be able to "un-SELV" the circuit as it were.
- Andy.
What standard would the 'created SELV' system be made to? I think you'd be assembling some arrangement (you'd need individual components, such as transformer, rectifier, capacitor etc.) and then we're into realms of Regulation 113.1. The standard for a DC supply is no longer BS EN 60950-1, but BS EN 62368-1, which is where the issue of "non-alignment" arises.
Chris, over the last few years, particularly in the more modern and "Trendy" high class hotels the bathroom, shower room, wet room has no physical door between the bath/shower area and the bedroom itself, yes some internal partitions may offer a small level of privacy. But in those cases not even a door to pass a lead underneath!! its just one aperture where the door would normally be.
GTB
I was thinking the SELV source could be to BS EN 61558-2-6 (something like this perhaps, https://uk.rs-online.com/web/p/din-rail-transformers/7720704, or maybe something less RS-priced) - I think that would then satisfy BS 7671's requirements for any specific standards for SELV systems - the remaining parts need only each need to comply with some suitable standard for each individual part. With any installation we're assembling parts complying with a wide variety of different standards - this would just be an extreme example of the same principle. If people don't fancy soldering together diodes, capacitors etc on site, ready built 12V AC to DC converters are available (e.g. https://www.autodoortrader.co.uk/12v-ac-dc-converter-1076-p.asp - but check standard compliance of course)).
- Andy.
What i need to offer is a solution so no soldering or building on site.
I need to consider real world risks to the client and their customer, not just be approved. With what im understanding is that an approved setup could still be fatal in the right situation. Limiting voltage to lower limits I.e 5-12v output, isolated supply and IP rating (marine) USB connector.
Although my first choice will be to discuss installing outside zone 2
Although my first choice will be to discuss installing outside zone 2
I am not sure that helps. As Andy has already mentioned, unless the supply is SELV, no socket-outlet is permitted within 2.5 m. The definition of socket-outlet is very broad and IMHO includes USB - it is not restricted to mains voltage.
That appliance does not comply with BS EN IEC 61558-2-5 and, accordingly, does not comply with BS 7671.
BS EN IEC 61558-2-5 20.6: Socket outlets in the output circuits of shaver supply units shall accept one or more type of plugs in accordance with IEC TR 60083 and shall not have a protective earthing contact.
IEC TR 60083 1. Scope and object: ... It is therefore limited to systems for a.c. with a rated voltage above 50 V but not exceeding 440 V ...
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