It was in the original post. The circuit is to distribute 110v from a site transformer to fixed outlets (EN60309 yellow type) to run power tools in the workshop. This is because it is a PITA lugging the transformer around and more convenient just to plug them into a wall outlet.
The transformer is an isolating type and has a centre tapped secondary giving 55-0-55v with the centre tap connected to ground.
Thus there are, in effect, two phase connections of 55v each (they are balanced about earth) and the earth. Neither of the 55v connections can be described as a neutral because it is 55v away from earth. Equally, no current will flow through the centre tapped wire unless there is a fault because it will be connected to the tool case or not connected.
It's isolated and balanced.......
.andy
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