Direct current circuit breaker (DC CB) is the key component to provide reliable operation of Multi-terminal Direct Current (MTDC) system. Fast, effective and accurate DC CB models are needed for system-level studies. Due to large number of components in the DC CB, its detailed modeling is needed in order to simulate current interruption process correctly. However, the simulation time may be longer depending on the network complexity. This paper proposes an average model which is compared to a detailed model of a Voltage-source-converter resonant current (VARC) DC CB in an MTDC system in terms of its performance and computation time for two typical simulation cases. The average and the detailed model are modelled and simulated in PSCAD/EMTDC environment. An accurate response of the average model during fast transient event is presented, showing additional computational advantage.