Voltage Levels around the World

This post has 745 words. It will take approximately 3 minutes, 43 seconds to read it.

All European and most African and Asian countries use a supply that is within 10% of 230V (Phase Voltage), whereas Japan, North America and some parts of South America use a voltage between 100V and 127V (Phase 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).


Voltage tolerances are for steady-state operation. Momentary heavy loads, or switching operations in the power distribution network, may cause short-term deviations out of the tolerance band. In general, power supplies derived from large networks with many sources are more stable than those supplied to an isolated community with perhaps only a single generator.


The choice of utilization voltage is governed more by tradition than by optimization of the distribution system. In theory a 230V distribution system will use less conductor material to deliver a given quantity of power. Incandescent light bulbs for 120V systems are more efficient and rugged than 230V bulbs, while large heating appliances can use smaller conductors at 230V for the same output rating.
Practically speaking, few household appliances use anything like the full capacity of the outlet to which they are connected. Minimum wire sizes for hand-held or portable equipment are usually restricted by the mechanical strength of the conductors. One may observe that both 230V system countries and 120V system countries have extensive penetration of electrical appliances in homes. National electrical codes prescribe wiring methods intended to minimize the risk of electric shock or fire.


Many areas using (nominally) 120V make use of three-wire, single-phase 240V systems to supply large appliances. Three-phase systems can be connected to give various combinations of voltage, suitable for use by different classes of equipment. Where both single-phase and three-phase loads are served by an electrical system, the system may be labelled with both voltages such as 120/208 or 230/400V, to show the line-to-neutral voltage and the line-to-line voltage. Large loads are connected for the higher voltage. Other three-phase voltages, up to 830 volts, are occasionally used for special-purpose systems such as oil well pumps.


Following voltage harmonization all electricity supplied within the European Union is now nominally 230V ± 10% at 50 Hz. For a transition period (1995–2008), countries that had previously used 220V changed to a narrower asymmetric tolerance range of 230V +6% −10% and those (like the UK) that had previously used 240V changed to 230V +10% −6%. Note that no change in voltage is required by either system as both 220V and 240 V fall within the lower 230V tolerance bands (230V ±6%). In practice this means that countries such as the UK that previously supplied 240V continue to do so, and those that previously supplied 220V continue to do so. However equipment should be designed to accept any voltages within the specified range.


As of the year 2000, Australia has converted to 230V as the nominal standard with a tolerance of +10% -6%, this superseding the old 240V standard, AS2926-1987. As in the UK, 240V is within the allowable limits and “240 volt” spoken as “two forty volt” remains a synonym for mains in Australian and British English.


In Japan, the electrical power supply to households is at 100V. Eastern and northern parts of Honshū (including Tokyo) and Hokkaidō have a frequency of 50Hz, whereas western Honshū (including Nagoya, Osaka, and Hiroshima), Shikoku, Kyūshū and Okinawa operate at 60Hz. To accommodate the difference, appliances marketed in Japan can often be switched between the two frequencies.


Large industrial motors (say, more than 250 HP or 150 kW) may operate on medium voltage. On 60Hz systems a standard for medium voltage equipment is 2300/4160V whereas 3300V is the common standard for 50Hz systems.

Vanguards Power (VP) is a leader in design, development and manufacture of 3rd Generation Power Optimisation Systems. VP Systems use state-of-the-art computer control to regulate and stabilise all incoming voltage into any building or site.


All VP Single and 3 Phase Systems have our unique Dynamic Digital Voltage Control (DDVC) system. Output Voltage settings can be changed by the User at any time without site power interruption – which further increases energy savings, more than any other Power or Voltage Optimisation System in the World.


VP range of single and 3 Phase Power Optimisation Systems are called: PropSava and LiteSava.


Where Sites experience main voltage delivery over 220V phase voltage (380V line voltage) electrical equipment is overpowered; power is wasted and all electrical equipment suffers premature failure with reduced life expectancy.


Be Sociable, Share!

Leave a Reply