The topic of internal electrical installations presented in this book includes all the elements that an electrical installer needs to know in order to carry out a complete electrical installation.

Continuing our effort towards the "new educational standardization" that we have already established, we have incorporated the coexistence of theory and practical applications in internal electrical installations. We believe that in this way, the studying reader will acquire the theory and standardized practices of today's modern electrical installations, while also becoming capable of adapting to the evolving technology in response to increasing demands.

We would like to thank all the staff from various companies related to the broad spectrum of electrical installation components for their assistance, information, and materials they provided us. Additionally, we consider it our duty to thank our colleagues Kostas Sgouras, Manolis Marakis, Giorgos Mina, and Giorgos Savvas, who, with their insightful observations, contributed to our effort.

Confident that our endeavor will receive the same response as previous ones, we welcome every critique with the aim of improving this book.

Stefanos Touloglou and Vangelis Stergiou