Does the banana clip connection lead carry any voltage? If not, would it be possible to use UK house mains earth pin (3 pin plug), as the connection between the 2 cases? This would permit maximum distance between units within the building without a long trailing lead.

Does the banana clip connection lead carry any voltage? If not, would it be possible to use UK house mains earth pin (3 pin plug), as the connection between the 2 cases? This would permit maximum distance between units within the building without a long trailing lead.