An employer shall ensure that -
(a) appropriate precautions are taken to prevent danger -
(i) when operating, installing, maintaining, transporting or storing auxiliary power supply batteries or auxiliary generators, and
(ii) to persons who install, maintain or use an electrical installation where auxiliary batteries or generators have been fitted or are intended to be fitted and
(b) where auxiliary batteries or generators have been fitted or are intended to be fitted appropriate precautions are taken to prevent danger to persons working on the external electrical network supplying an electrical installation.