In very dense city areas, a secondary network may be formed with many transformers feeding into a common bus at the utilization voltage.

The choice of utilization voltage is governed more by tradition than by optimization of the distribution system.

With AC, transformers can be used to step down high transmission voltages to lower customer utilization voltage.

Standard power utilization voltages and percentage tolerance vary in the different mains power systems found in the world.

In very densely populated areas, "secondary networks" are used, with many distribution transformers feeding a "grid" at the utilization voltage.

Customers desiring service at nonstandard voltages provide all the necessary facilities to convert a standard service voltage to the desired utilization voltage.

Split-phase electric power is used when three-phase power is not available and allows double the normal utilization voltage to be supplied for high-power loads.

Both devices operate well on DC, but DC could not be easily changed in voltage, and was generally only produced at the required utilization voltage.

A distinction should be made between the voltage at the point of supply (nominal system voltage) and the voltage rating of the equipment (utilization voltage).

Distribution transformers again lower the voltage to the utilization voltage of household appliances and typically feed several customers through secondary distribution lines at this voltage.

The utilization voltage delivered to equipment such as lighting and motor loads is standardized, with an allowable range of voltage over which equipment is expected to operate.

Higher voltages could not so easily be used with the DC system because there was no efficient low-cost technology that would allow reduction of a high transmission voltage to a low utilization voltage.

One technique attempted for conversion of direct current from a high transmission voltage to lower utilization voltage was to charge series-connected batteries, then reconnect the batteries in parallel to serve distribution loads.

Typically the utilization voltage is 3% to 5% lower than the nominal system voltage; for example, a nominal 208 V supply system will be connected to motors with "200 V" on their nameplates.

The choice of utilization voltage is due more to historical reasons than optimization of the distribution system-once a voltage is in use and equipment using this voltage is widespread, changing voltage is a drastic and expensive measure.

The distribution feeders consist of combinations of overhead and underground conductor, 3 phase and single phase switches with load break and non-loadbreak ability, relayed protective devices, fuses, transformers (to utilization voltage), surge arresters, voltage regulators and capacitors.

Multiwire systems split more than two ways are possible with both AC and DC but have the significant disadvantage that no matter which point is tied to ground some of the wires will have a higher earth relative voltage than the utilisation voltage; therefore, such systems are not used in normal power distribution.