Under normal conditions, how does the voltage measured between line and neutral of a 3-phase, 4-wire "Y" system compare to the voltage measured line to line?

In a 3-phase, 4-wire "Y" (or star) system, the relationship between line-to-neutral voltage and line-to-line voltage is defined by the square root of three (√3). The voltage measured between line and neutral is less than the voltage measured between any two line conductors (line-to-line).

In a "Y" system, each of the three phase conductors is connected to a neutral point, which is the common point where the three phases meet. The voltage from each phase to the neutral point (line-to-neutral voltage) is typically referred to as the phase voltage. When measuring between two of the phase lines (line-to-line voltage), you see a voltage that is higher than that of the line-to-neutral measurement. This is due to the geometry of a three-phase system, where line-to-line voltage is calculated as the phase voltage multiplied by √3 (approximately 1.732).

Therefore, under normal operating conditions, the line-to-neutral voltage in a 3-phase, 4-wire "Y" system is indeed less than the line-to-line voltage.