2 pôles
3 pôles (L1, L2, L3, ...)
3 pôles + N (L1-N, L2-N, L3-N, ...)
rail hybride 4p-2p 18 mod L1,L2,L3,N-L1,N,L2,N,L3
4 pôles (L1, L2, L3, N, ...)
Unibis