Discuss Examples of, anyone? in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net

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the pict

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Can anyone give me examples of
"Use of electrical seperation to supply an individuall item of equipment",
and as above for more than one, I have read through 418.3 etc but I cannot find an example, I know that it is outside the remit of BS7671 to provide examples for everything, the book would run to several volumes, however a few examples would help
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the pict

the pict

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Yes in a domestic situation the shaver point is selv but it is the "provision of a SELV circuit" I should have asked what in your experience in a commercial environment are examples you have come across equipment wise and why was it seperated and how,
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the pict

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Absoulutly correct Richard, I stand corrected, I was thinking of the seperated aspect, but I really must pay more attention, more caffiene required
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Good one Davey, to be honest I am struggling to find any other than similar to your suggestion probably schools colleges etc, elv lighting apart
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stef

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Hi pict, try 110 V tranny for electrical hand tools, low voltage transformer for 12v downlighters, high/ low voltage transformers in substations, transformers for door bells, mobile phone chargers from the 90s ( not the modern ones you get today cos they aren't sepparating, really), ...
 
S

StuSpiers

Blackely units in schools.

Although they don't supply one item they are for bench sockets usually.
 

ackbarthestar

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Separated circuits, as suggested by others, don't have to be SELV.

Any circuit that employs the use of a isolating transformer where there is no earth return path on the secondary side. Hand tools, pumps compressors, used in cable tunnels where there is restricted access/movement see section 706
 
D

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To be honest, a shaver socket does not really fit the bill as an example.
A better example would be a bell circuit that uses a transformer that fits into a CU.
 
E

Edd

To be honest, a shaver socket does not really fit the bill as an example.
A better example would be a bell circuit that uses a transformer that fits into a CU.
Why do you say its not a good example? They have 2 outputs one of 230v and the other 110v, both fed from an isolating transformer, no earth conection. In my eyes its sole means of protection is electrical seperation, its not relying on selv or any other means. your bell example is using selv as its main means of protection.
 
D

Deleted member 26818

Why do you say its not a good example? They have 2 outputs one of 230v and the other 110v, both fed from an isolating transformer, no earth conection. In my eyes its sole means of protection is electrical seperation, its not relying on selv or any other means. your bell example is using selv as its main means of protection.
A shaver socket is not an individual item of equipment that is supplied via a separated source.
An item of equipment plugged into the shaver socket would be supplied by a separated source, however such an item would fall outside of the scope of BS7671.
 
E

Edd

however such an item would fall outside of the scope of BS7671.
Can you point to where please, as i have always put on Domestic EICR's that the shaver point was a form of electrical seperation. and on comersial I would use a site transformer as electrical seperation. The NIC has never told me I was wrong. But I always like it if they are :)
 
A

Adam W

I would have said a shaver socket is a better example than a door bell - a door bell would be SELV. Separated yes, but also ELV which wasn't asked for.
A shaver socket is probably the example they're looking for.
An isolating transformer supplying more than one item of equipment could be a site transformer.
 
D

Deleted member 26818

Both a shaver socket and a site transformer are examples of a source of electrical separated supplies.
However neither are individual items of equipment suplied by electrical separation.
 
E

Edd

Both a shaver socket and a site transformer are examples of a source of electrical separated supplies.
However neither are individual items of equipment suplied by electrical separation.
I see where you are coming from with that, but as theres a sepreate tick box for selv, if you had no selv in an instalation but you did have a shaver point, would you put N/A in the electrical seperation box? that then means the shaver point is not checked except for its bs number under BS 7671. The way I see it any Isolation transformer that supplys a piece of equipment with voltages greater than selv should be checked for electrical seperation. otherwise in your eyes it falls under no catogry at all. But I do see what you mean about it not being a piece of equipment :)
 
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stef

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Both a shaver socket and a site transformer are examples of a source of electrical separated supplies.
However neither are individual items of equipment suplied by electrical separation.
I disagree, they are supplied from the HV / LV tranny in a substation:biggrinjester:
 
A

Adam W

I seem to remember on the old schedule of inspections there were separate boxes for circuits supplying one item of equipment, and multiple items. On the new EICR SOI there are sections under locations containing a bath or shower for
'Where used as a protective measure, requirements of SELV or PELV met (701.414.4.5)' and
'Shaver sockets comply with BSEN61558-2-5 formerly BS3535 (701.512.3)'.

If for whatever reason you had some non-standard system of electrical separation it could be listed under comments, but I would think that would be too rare to warrant a dedicated box on the form.
 
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