This second edition updates references to relevant regulations standards & publications. It replaces references to the Institution of Electrical Engineers' IEE Regulations with BS7671. This book is relevant to all work activities & premises except mines & quarries certain offshore installations & certain ships. The guidance is intended to assist duty holders in meeting the requirements of the Regulations. It will be of interest & practical help primarily to engineers (including those involved in the design construction operation or maintenance of electrical systems & equipment) technicians & their managers.