230V / 110V Segregation

Question

230V / 110V Segregation

Ahr35181 (Electrical)

(OP)

11 Dec 03 09:53

We have an installation going ahead which involves 230V & 110V fused spurs with IEC (kettle) sockets connected via short lengths of pvc/pvc cables. They are in the same location supplying 230V & 110V IT equipment.

I've been looking in BS7671 to try & find a reg that says this can't be done, i.e the leads could quite easily be mixed up!! It's been suggested that we use caution labels, but is this enough as it will still be possible to mix the leads up!!

Thanks in advance,

Alan

BrianG (Military) · Answer 1 · 2003-12-12 02:40:01

Why can't you make all the IT equipment run at the same voltage?

ScottyUK (Electrical) · Answer 2 · 2003-12-12 07:19:55

BS7671, to quote its full title, is the 'Requirements for Electrical Installations'. Appliance leads are not part of the 'installation', and thus aren't covered by the wiring regs.

Ahr35181 (Electrical) · Answer 3 · 2003-12-12 13:42:20

ScottyUK,

I agree with your comment to a certain extent, the IEC leads are supplying 'portable' current using equipment which are manufactured to a standard other than BS7671. But because the leads are connected to fused spurs rather than non interchangeable plugs, the electrical 'installation' may cause danger or damage to equipment if the leads were mixed up.

Maybe there is a reference to my query in an equipment standard BS / BS EN which may help? Unfortunately I don't have access to equipment standards.

Alan

ScottyUK (Electrical) · Answer 4 · 2003-12-14 20:36:15

This just keeps getting better!

Could you consider using the industrial type of plug & socket (the yellow or blue types for 110V & 240V respectively)?

BS7671 doesn't cover portable equipment, whatever its origin. BS7671 stops at the final circuit outlet, be it a socket or a fused spur. The equipment fed from the final circuit is covered by one of the multitude of other BS/EN regs. Sorry I don't know which one - I will have to defer that to someone else.

One question at something of a tangent: is your 110V supply earth-referenced, i.e. a 110V 'live' and 'neutral' where the neutral is connected to earth, or is it floating? If it is floating, you should consider connecting one end to earth.

Ahr35181 (Electrical) · Answer 5 · 2003-12-15 05:24:58

ScottyUK,

Thanks for your reply, we've settled with durable caution notices.

The floating neutral query has been a problem where I work for quite some time. We specify 110-0V tx's with a secondary fuse & white neutral link, linked to earth. Time & time again we get tx's with two secondary fuses (floating neutral)& end up modifying them ourselves. I can't understand how these transformers meet the required standards, offering no earth fault current return path???

Alan

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230V / 110V Segregation