3x230

[Pete999]

Am I missing something? Where or how are you measuring 230v between two lines?

Me as well

 

[Lucien Nunes]

I think it's a hypothetical question, I didn't get the impression that the OP was actually measuring this voltage. But systems that work in this way do exist, shipboard delta supply was one I mentioned. I also have a 20kVA generating set of the same voltage, 133V L-N, 230V L-L, but it's corner-grounded so the neutral star point is of no use and isn't brought out to the panel. You can have two supplies of 230V sharing what looks like a neutral, but when you measure between them, instead of 400V, you get 230V again because they're 60° apart not 120°.

 

[davesparks]

How do table lamps get away with Schuko plugs though? Id imagine some safety mechanism is used on those sockets.

Schuko plugs aren't used in this country so there is no point attempting to apply our regs to them

 

[snowhead]

Thanks

Id argue the same risks with a lamp also apply to a light fitting.

For changing a lamp a D.P switch in a fixed system provides isolation of both poles.
For changing a lamp with a Schuko plug, pulling the plug provides D.P isolation

 

[Gardner]

I think it's a hypothetical question, I didn't get the impression that the OP was actually measuring this voltage. But systems that work in this way do exist, shipboard delta supply was one I mentioned. I also have a 20kVA generating set of the same voltage, 133V L-N, 230V L-L, but it's corner-grounded so the neutral star point is of no use and isn't brought out to the panel. You can have two supplies of 230V sharing what looks like a neutral, but when you measure between them, instead of 400V, you get 230V again because they're 60° apart not 120°.

Its a center grounded wye made with 135 volt wingdings to give 230 volts L-L. It is indeed TN rather then IT.

Schuko plugs aren't used in this country so there is no point attempting to apply our regs to them

Id imagine the interior wiring would still be applicable, no?

 

[Lucien Nunes]

We seem to be going round in circles, because we don't know your motivation in asking the question and hence what parameters you are aiming to specify. Do you have equipment that you want to operate in the UK that expects such a supply? Or do you want to apply BS7671 to an installation outside the UK with this supply configuration? Or is it purely an academic question?

The UK LV electrical supply is standardised as 230/400 with one leg of single phase supplies at or near ground potential, for general applications. For specific purposes, you can use whatever voltage and configuration is necessary, but not for the general wiring of buildings. The specification of the supply delivered to the consumer's terminals falls outside the scope of BS7671, governed instead by the ESQCR.

Portable appliances are also outside the scope of BS7671 and must achieve pan-EU compatibility in order to be CE-marked and hence permissible to sell. As per posts 19 & 29, a portable appliance has double-pole isolation inherent when unplugged, so does not require special provisions for compatibility with supplies of unknown polarity.

 

[Gardner]

We seem to be going round in circles, because we don't know your motivation in asking the question and hence what parameters you are aiming to specify.

Ive asked what parameters I am interested in. Mainly if the IEC or BS allows such a system for domestic use and what special conditions need to be taken if any.

Do you have equipment that you want to operate in the UK that expects such a supply? Or do you want to apply BS7671 to an installation outside the UK with this supply configuration? Or is it purely an academic question?

Applying BS7671 to an installation outside the UK with such a configuration.

The UK LV electrical supply is standardised as 230/400 with one leg of single phase supplies at or near ground potential, for general applications. For specific purposes, you can use whatever voltage and configuration is necessary, but not for the general wiring of buildings.

What rules force 230 L-N for a building or domestic supply?

The specification of the supply delivered to the consumer's terminals falls outside the scope of BS7671, governed instead by the ESQCR.

Correct, but when a DNO provides 133/230Y TN-S as a supply, how can that be applied within the regs to a building?

Portable appliances are also outside the scope of BS7671 and must achieve pan-EU compatibility in order to be CE-marked and hence permissible to sell. As per posts 19 & 29, a portable appliance has double-pole isolation inherent when unplugged, so does not require special provisions for compatibility with supplies of unknown polarity.

I understand this part BTW, I think its the socket design that allows Schuko plugs in table lamps. The ones Ive seen appear to have a guard so the threads can not be touched when energized.

 

[Octopus]

FFS just answer the question as to your location or do the mods need to look at your IP address?

Its not that difficult question is it?

 

[Gardner]

FFS just answer the question as to your location or do the mods need to look at your IP address?

Its not that difficult question is it?

Why does it matter? I am using IEC60364 with electricity obeying the same laws of physics regardless where that job will take place. Location will not answer my questions as to what a code or reg itself requires.

 

[Octopus]

Why does it matter? I am using IEC60364 with electricity obeying the same laws of physics regardless where that job will take place. Location will not answer my questions as to what a code or reg itself requires.

Very simply because when posters with hold facts, you start wondering what the F is going on..... why would concealing your location really matter?

 

[uksparks]

Cape Town.

Sorry, I meant Gardner

 

[davesparks]

Why does it matter? I am using IEC60364 with electricity obeying the same laws of physics regardless where that job will take place. Location will not answer my questions as to what a code or reg itself requires.

But the regulations change according to location,

 

[7029 dave]

UK only, can't comment else where.

 

[Gardner]

Very simply because when posters with hold facts, you start wondering what the F is going on..... why would concealing your location really matter?

No, I think you simply dont know the answer. Sometimes people will shift the subject to avoid what they can not answer. Its either a simple yes or no with a code reference number. I have a good guess what will happen when I give a location: "check the local codes applicable to your country, they will have the answer your looking for" I this scenario its IEC60364 which BS7671 is closely modeled by.


FWIW when others post on forums like Mike Holt's asking about NFPA70 they are given responses around NFPA70 even if their location is Saudi Arabia or Brazil. Often over seas jobs require them asking such questions so no one asks to begin with.

 

[Gardner]

But the regulations change according to location,

Thats not even a valid answer. I know of many instances where foreign codes are applied in another country such as for example NFPA70 in US military installations inside the Middle East. Second many poor countries use the raw IEC60364 with little change. Third its possible to wire any building in the UK with say the German or French regs provided part P can be proven as fulfilled.

 

[7029 dave]

Thats not even a valid answer. I know of many instances where foreign codes are applied in another country such as for example NFPA70 in US military installations inside the Middle East. Second many poor countries use the raw IEC60364 with little change. Third its possible to wire any building in the UK with say the German or French regs provided part P can be proven as fulfilled.

Part p is an building reg, nothing to do with IET.

 

[davesparks]

Thats not even a valid answer. I know of many instances where foreign codes are applied in another country such as for example NFPA70 in US military installations inside the Middle East. Second many poor countries use the raw IEC60364 with little change. Third its possible to wire any building in the UK with say the German or French regs provided part P can be proven as fulfilled.

You cannot fulfill the requirements of part P with an installation designed to any regs other than bs7671

 

[PEG]

Has the OP won this fishing match yet? ... His keep-net is full...:biggrinjester:

 

[Octopus]

Has the OP won this fishing match yet? ... His keep-net is full...:biggrinjester:

He should change his name to Richard Head

 

[davesparks]

Is such a system (230 volt L-L) legal under BS7671 or IEC 60364? Do I need double pole switches for light fittings?

It is possible to design and construct an installation which uses such a supply in accordance with bs7671. However bs7671 is not law and so compliance with it cannot be described as legal. The law which governs electricity supplies in the uk is the electricity supply quality and continuity regulations (esqcr) which may prohibit such a supply from being provided to a customer.

Under bs7671 you would need to break all conductors which are not referenced to earth at substantially the same time, so yes you would need to provide double pole switching for light fittings.

Further to this you cannot use bs1363 plugs and sockets on such a supply as they are fused in one pole only, as a result the ring final circuit would not be useable. You would need to use a plug and socket system which is not fused or polarised, you may be able to use bs546 plugs and sockets for this.

 

[Gardner]

You cannot fulfill the requirements of part P with an installation designed to any regs other than bs7671

Nowhere do the building regs say BS7671 must be used.

 

[Gardner]

Part p is an building reg, nothing to do with IET.

Exactly my point. I could wire a building with German regs, nothing holds me to BS7671.

 

[7029 dave]

Exactly my point. I could wire a building with German regs, nothing holds me to BS7671.

Not in the UK we adhere to BS7671

 

[davesparks]

Nowhere do the building regs say BS7671 must be used.

Approved document P, section 1, line 1:
"Electrical installations should be designed and installed in accordance with BS 7671:2008 incorporating Amendment No 1:2011"

 

[Gardner]

It is possible to design and construct an installation which uses such a supply in accordance with bs7671. However bs7671 is not law and so compliance with it cannot be described as legal. The law which governs electricity supplies in the uk is the electricity supply quality and continuity regulations (esqcr) which may prohibit such a supply from being provided to a customer.

Thanks

Under bs7671 you would need to break all conductors which are not referenced to earth at substantially the same time, so yes you would need to provide double pole switching for light fittings.

Got it. All MCBs are 2 and 3p. What part of the regs require 2p switching for light fittings? Not saying it does not exist but just want to have a reg reference.

Further to this you cannot use bs1363 plugs and sockets on such a supply as they are fused in one pole only, as a result the ring final circuit would not be useable. You would need to use a plug and socket system which is not fused or polarised, you may be able to use bs546 plugs and sockets for this.

Schuko plugs will be used with 16 amp MCBs. No rings either.