A 3Ø, 4-W supply system delivering 277/480 volts is what type of connection?

In a 3-phase, 4-wire supply system delivering 277/480 volts, the correct configuration is a Wye (or Star) connection.

In a Wye connection, each phase is connected to a common neutral point, effectively creating four wires: three phase wires and one neutral wire. The voltage measured across each phase to neutral is 277 volts, while the line-to-line voltage (the voltage between any two phases) is 480 volts. This characteristic of the Wye connection allows for both 277 volts for single-phase loads and 480 volts for three-phase loads.

The option of a Delta connection is typically associated with a three-wire system, as it does not use a neutral wire in the same way that a Wye does. In Delta configurations, the line-to-line voltage is equal to the phase voltage multiplied by the square root of three, which is not consistent with the specified voltage levels of 277/480.

The other options, parallel and series connections, are not applicable in this context as they refer to different configurations that are not typically used for three-phase power distribution. A parallel connection implies multiple independent circuits sharing common voltage levels, and a series connection is used to describe components arranged such that the current flows