Wave-function components containing a single Δ isobar are included in the calculation of the three-nucleon bound state. In extension to previous work, a nucleon-Δ potential based on meson exchange is incorporated in the interaction models. The interaction models are constructed phase equivalent with the purely nucleonic Paris and Bonn one boson exchange potential in q space (OBEPQ) potentials. The nucleon-Δ potential yields an additional contribution of the order of 0.1–0.2 MeV to the effective three-nucleon force. Its effect on the electromagnetic properties of the three-nucleon bound state is also considered and found to be small
