Here are some more portable site transformers, up to 3kVA:
http://www.tlc-direct.co.uk/Main_Index/Transformer_Index/Site_Transformers/index.html As well as these portable single-phase xfmrs, large sites can also have 3-ph distribution, a Y secondary with grounded star-point, 110V between phases, 63V phase-to-ground. There no distributed neutral; 110V power tools are connected between two phases.
Follow the links on this page to see the BS4343 connectors in more detail:
http://www.tlc-direct.co.uk/Main_Index/Plugs_and_Sockets_Industrial_Index/index.html The color coding is for the maximum voltage which exists, either phase to ground or between phases. So 110V 2P+E are yellow, 230V 2P+E are blue, and 4P+E for 230/400V 3-phase Y are red.
[This message has been edited by pauluk (edited 06-12-2006).]
[This message has been edited by pauluk (edited 06-12-2006).]
