\input{Preambule}%

\begin{document}
\begin{tikzpicture}[%
    show background rectangle,%
    tight background,%
    background rectangle/.style={fill=white}%
  ]
  \tikzset{%
    point/.pic={%
      \fill[black] (0,0) circle[radius=0.05];%
    }%
  }%

  %
  % Conducteurs
  %
  % Neutre
  \coordinate (neutral center) at (0,8);%
  \draw (neutral center) pic {point} node [below left] {N};%
  \draw (neutral center) circle[radius=1];%
  \draw (neutral center) circle[radius=0.90];%

  % Phases
  \foreach \x/\y/\z/\p in {a/135/A/below,b/45/B/right,c/-90/C/left} {%
      \path (neutral center) ++(\y:2.5) coordinate (\x\space center);%
      \draw (\x\space center) pic {point} node[\p] {\z};%
      \draw (\x\space center) circle[radius=1.5];%
      \draw (\x\space center) circle[radius=1.4];%
    }%
  \draw[dashed] (neutral center) circle[radius=4];%

  %
  % Annotations
  %
  % Exterior diameter
  \draw[{Latex[]}-{Latex[]}] (neutral center) ++(5,-4)%
  coordinate (bottom dext)%
  -- ++(0,8) coordinate(top dext)%
  node[midway, right] {$d_{\mathrm{ext}}$};%
  \draw[dashed] (neutral center) ++(0,4) -- (top dext);%
  \draw[dashed] (neutral center) ++(0,-4) -- (bottom dext);%

  % External diameter divided by 4
  \draw[{Latex[]}-{Latex[]}] (neutral center) -- (b center) %
  node [pos=0.6, above] {$\dfrac{d_{\mathrm{ext}}}{4}$};%

  % Arc
  \draw[dashed] (neutral center) -- ++(0,-5);%
  \draw[dashed] (neutral center) -- ++(135:5) coordinate (start arc);%
  \draw[{Latex[]}-{Latex[]}] (start arc) arc[start angle=135, end angle=270, radius=5]%
  node [midway, below left] {$\dfrac{2\pi}{3}$};%

  % Radius neutral
  \draw[{Latex[]}-{Latex[]}] (neutral center) -- ++(-45:0.9) node[midway, above right] {$R_{\nrm}$};%

  % Radius phase
  \draw[{Latex[]}-{Latex[]}] (a center) -- ++(-135:1.4) node[midway, above left] {$R_{\arm}$};%
\end{tikzpicture}
\end{document}
% Local Variables:
% mode: latex
% TeX-engine: luatex
% TeX-source-correlate-method-active: synctex
% ispell-local-dictionary: "british"
% coding: utf-8
% LaTeX-indent-level: 2
% fill-column: 120
% End:
