Understage Isolators
The understage isolators are mains power isolators located in the plant room under the stage, which take mains power, as provided by the Lord our Bruce (and embodied in the National Grid), and provide all stage power (lighting and sound).
There are two isolators, both providing 415V, 125A 3 phase (3P+N+E) power. One provides power to the dimmer system, the other to the distro box.