Question but not PLC specific

[font=&quot]I'm needing to know a little about the European / Asian electrical supply configurations: I know that the basic line voltage is "220V" between lines but is one of the lines pulled to ground (i.e.: neutral) or are both floating in respect to Ground? If someone could direct me to a link of book title delving into the electrical distribution schema used in other than the US I would appreciate it. WE are building industrial test equipment used in house in both Europe, Mexico and China. I do NOT want to put maintenance personnel is harms way![/font]

[font=&quot]Thanks[/font]

[font=&quot]Butch[/font]

In the UK, the neutral is grounded. One lead is 220 hot, the other is zero.
Asia is variable. Japan and China are different for example.

We have -in Finland- 400V 3 phase Y-connected secondary system where 1-phase voltage is 230V between neutral (grounded) and phase,
even my home and allmost all homes. It is very common voltage system in North Europe. Common nominal voltage is 400/230V, earlier it was 380/220V.

Forgot the links.
UL and International Standards for Industrial Control Equipment

seppoalanen said:

We have -in Finland- 400V 3 phase Y-connected secondary system where 1-phase voltage is 230V between neutral (grounded) and phase,
even my home and allmost all homes. It is very common voltage system in North Europe. Common nominal voltage is 400/230V, earlier it was 380/220V.

Click to expand...

Technically the voltage in most EU countries is standardised at 230/400V +/-10%. For historical reasons there is, however, some variation within that range. The actual UK voltage is normally 240/415V whereas much of continental Europe uses 220/380V. This is because the standard was a fudge to give the impression of a common voltage without actually changing the status quo. This practice was quite common when the Euronorm standards first appeared but thankfully seems to be much rarer nowadays.
Andybr

The standard European voltage of 230V single phase and 400V three phase +10/-6% actually exists as the harmonised norm since 1995, and is quoted in the Electricity Supply Regs.

It is due to be updated to +10/-10%, but I don't think this has been ratified yet.

The European harmonised colours are Phase 1(L1) - Brown, Phase 2(L2) - Black, Phase 3(L3) - Grey, Neutral - Blue, Earth - Green/Yellow on three phase installations, however three brown phases are acceptable if correctly identified, and Phase - Brown, Neutral - Blue, Earth - Green/Yellow on single phase installations.

There are also multiple methods of supply earthing with the most common being PME, called TN-C-S in BS7671, where the Neutral is grounded at the local supply transformer.

Jon.

Ozz is 240/415V with an MEN system (main earthed neutral). The MEN point is at the main switch board. Earthing is by earth rod - too many dead plumbers when using water pipes - also hard to get an earth on plastic pipes.

I have seen voltage vary here up to 267 volts in the middle of the night in one place. Not nice.