The Natural Philosopher wrote:

Andy Burns wrote:

The Natural Philosopher wrote:

No RCD/RCBOÂ* has a 'functional earth fly lead'.

The white lead here ...

...is not part of the trip function.

Zoom in ... it's shown as part of the circuitry measuring current
differences

https://images.squarespace-cdn.com/content/v1/5ec649c17e93ee14ea6f1a9b/1594219056973-3YJBH0HJX2Y5AZISSGW8/ke17ZwdGBToddI8pDm48kPlAdDxmOe2wO-VlVH21GUIUqsxRUqqbr1mOJYKfIPR7LoDQ9mXPOjoJoqy81S2I 8PaoYXhp6HxIwZIk7-Mi3Tsic-L2IOPH3Dwrhl-Ne3Z2KbNUfoO6AOkUKHX6DcHzYjCBx_xjkpU-kAGxUEirxz46liCGkj4dr9PBmyqqYlee/6310S.jpg

No idea what its for, perhaps to
earth something in the switch...