What is the voltage between a hot line and ground on a 240-volt delta power supply?

In a 240-volt delta power supply system, the configuration involves three phases, each at 240 volts. The voltage between a hot line (one of the phases) and ground in this setup is not usable for standard electrical applications. Instead, the voltage available is typically measured between two of the hot lines, which would give the full 240 volts. However, measuring the voltage of a single hot line to ground does not produce a usable voltage for typical devices because of the delta configuration, which lacks a neutral point at ground potential.

Thus, the voltage between a hot line and ground in this configuration does not yield a significant or usable voltage, making "no usable voltage" the correct characterization of the situation.