When a 3Ø, 3-W supply system delivers 240 volts, how is the system connected?

In a three-phase, three-wire system that delivers 240 volts, the system is typically delta connected. In a delta configuration, the three phases are connected end-to-end, forming a closed loop or triangle. Each line voltage in a delta system is equal to the phase voltage (the voltage between any two lines), which in a typical 240-volt delta system results in a line-to-line voltage of 240 volts.

In contrast, if the system were wye connected, the line voltage would be higher than the phase voltage, and a typical wye setup would have a line voltage of approximately 277 volts when the phase voltage is 480 volts. Therefore, the 240-volt output strongly indicates a delta connection, as this configuration allows for the direct line-to-line voltage observed.

Phased connected is not a standard terminology used in electrical wiring. Single-phase connected would imply a different setup altogether, only involving two conductors and primarily used for residential or smaller loads, rather than a three-phase system. Thus, the characteristics of a three-phase delta connection make it the suitable answer for a 240-volt delivery system.