I don't work on 3-phase very often, so I thought I'd take a chance yesterday to get some photos of a typical British 3-phase service entrance for small commercial premises.

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The feeder is underground, tapped from the mains under the street, and enters the bottom of the light gray panel. The pull-outs at the top of that block are cartridge fuses to BS1361, in this case rated at 60A each. Notice that the fuses and cables entering the meter have been tagged for phase identification (red, yellow, blue).

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The right hand side of the entrance unit contains the neutral terminal block. You should also be able to see a green/yellow cable entering the block top right. This is a PME (TN-C-S) installation, and it is at this block at which the building earth is bonded to the neutral (unlike in the U.S., ground and neutral are always kept separate in panels).

The label on the service block says:
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WARNING -- PROTECTIVE MULTIPLE EARTHED INSTALLATION -- DO NOT INTERFERE WITH EARTH CONNECTIONS