How many conductors are required to connect a three-phase delta connected heater bank to an electric power panel board?

A three-phase delta connected heater bank requires three conductors for its connection to an electric power panel board. In a three-phase system, each phase corresponds to one conductor. The delta connection itself does not require a neutral conductor since it is a closed loop formed by connecting the phases directly to each other. This means that the heater bank operates with the three phases providing power directly, so one conductor is needed for each of the three phases. Thus, the correct answer reflects the fundamental principle of three-phase power systems, which rely on three conductors to deliver the necessary power to the load.