Which of the following is not a common voltage supplied by a wye-configured system?

In a wye-configured electrical system, the common line-to-neutral voltage values are typically based on the configuration of the transformer and the system's overall design. For a standard three-phase wye system, the common line-to-neutral voltages are often 120 VAC and 240 VAC, which are derived from the 208 VAC (line-to-line) in a standard 120/208 V configuration and from the 480 VAC (line-to-line) in a 277/480 V configuration.

The voltage of 240 VAC is indeed a common voltage, especially in residential or light commercial applications, due to its configuration in certain wye setups. However, 240 VAC does not typically arise from a standard three-phase wye configuration when referring to line-to-line voltages since it is more commonly seen in single-phase systems.

When you compare 120 VAC, 208 VAC, and 480 VAC, each of these belongs to standard three-phase system configurations and can be obtained directly in such setups. Thus, while 240 VAC is used in various applications, it is not recognized as a standard voltage in a wye-configured three-phase system when operating under common definitions of line-to-neutral or line-to-line voltages. This distinction helps