Test equipment for site power lives here, led by the PCE 32A 415V 3P+N+E diagnostic plug. It connects to a five-pin ceeform outlet and its LED display shows what the socket is delivering: whether each phase is present, which way the phase rotation runs, and whether neutral and earth check out. Phase rotation matters as much as presence, since motors and chain hoists driven the wrong way round are a hazard, and reversed rotation shows up on the display before anything is connected.

On unfamiliar venue distro that check takes seconds and can save hours of fault-finding or worse. It covers the 32A five-pin outlets common on venue and event power. Keep it in the toolbox rather than buried in a flightcase, since the point of a diagnostic plug is that it gets used every time. The power and cabling categories carry the ceeform cable and distribution this plugs into.