AS/NZS 3112

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Australian standard three pin plug, with part insulation on the Active/Line and Neutral pins. Aust AC plug.jpg
Australian standard three pin plug, with part insulation on the Active/Line and Neutral pins.

AS/NZS 3112 is the harmonised Australian and New Zealand standard for AC power plugs (male) and sockets (female). The standard is used in Australia, New Zealand, Fiji, Tonga, Solomon Islands, Papua New Guinea and several other Pacific island countries. The International Electrotechnical Commission (IEC) "world plugs" Web site calls this plug Type I. [1]

Contents

The plug consists of two flat pins forming an inverted V-shape, plus a vertical earthing pin. Double insulated appliances omit the earth pin. When viewing a plug from the rear, the top left pin is active and the top right pin is neutral. The shank of the active and neutral pins of every 10 amp and 15 amp flat-pin plug sold after 3 April 2005 are required to be insulated, in accordance with AS/NZS 3112:2000. [2]

(Note that, in a single phase installation in Australia/NZ, the "Line" or "Phase" connection is referred to as the "Active" connection.)

Since 2000, the nominal voltage in most areas of Australia has been 230 V, [3] [4] [5] except for Western Australia and Queensland which both remain at 240 V, [6] though Queensland is transitioning to 230 V. The voltage in New Zealand is also 230 V. In Fiji, Tonga and Papua New Guinea it is 240 V, and in the Solomon Islands it is 220 V. The standards of China and Argentina also use the type I plug and socket, though the live and neutral pins are reversed in Argentina, and the plugs and sockets are upside-down in China. In both countries the voltage is 220 V. The differences in voltage may give rise to compatibility issues, especially for travellers and those purchasing appliances overseas or online. Connecting a 110 volt appliance to a 230 volt outlet, for example, can damage or destroy the appliance. Voltage adapters may be used to overcome the problem. The mains frequency is 50 Hz in all these countries.

Description

Dual 3-pin socket-outlet construction Dual 3 Pin Power Outlet - Construction.jpg
Dual 3-pin socket-outlet construction
Switched dual 3-pin socket-outlet Australian Dual Socket Outlet.jpg
Switched dual 3-pin socket-outlet
Socket-outlet, using insulation displacement as a means of connecting to low voltage (230 V) supply conductors Australian "Quick Connect" (Dual) Power Outlet.jpg
Socket-outlet, using insulation displacement as a means of connecting to low voltage (230 V) supply conductors

AS/NZS 3112 compliant plugs have two flat pins forming an inverted V-shape plus a vertical earthing pin. The flat blades measure 6.35 by 1.6 mm (14 by 116 in) with the active (line) and neutral pins 17.35 mm (1116 in) long set 30° to the vertical and the vertical earth pin being 20 mm (0.787 in) in length. [7] The pins are arranged at 120° angles around a common midpoint, with the active and neutral centred 7.92 mm (516 in) from the midpoint, and the earth pin centred 10.31 mm (38 in) away. [7]

A standard socket-outlet provides a nominal voltage of 230 volts RMS [3] at a maximum of 10 amps and always includes an earth connection. "Shuttered" socket-outlets are available, but these are not required by regulation.

There are unearthed versions of the plug used with this outlet having only the two flat inverted V-aligned pins, without the earthing pin. Such plugs are only to be used for devices where other safety standards are in use (e.g. double insulation) and these plugs are rated at a maximum of only 7.5 amps. They are not available separately but only integrally with power cords specifically designed for the purpose.

A view of the wiring side of a typical dual socket-outlet is also shown on the right, together with an annotated view of the mechanism, without the front cover. (One "rocker" switch has been disassembled to show its operation.)

If required, such dual socket-outlets can be obtained (at additional cost) using insulation displacement as a means of connecting to the supply conductors, as can be seen in the illustration - below right. [8] [9] The benefits claimed for their use in these applications include up to 50% faster installation, due to the reduction in the stripping, twisting and screwing down processes.

Switch requirements

Socket-outlet, auto switched by plug insertion. Automatically switched socket-outlets such as these may be used to supply power to refrigerators, some computers and other accessories that normally should not be switched off. The absence of a user operable switch prevents the accidental switching off of such devices Australian Socket-Outlet, Auto Switched.jpg
Socket-outlet, auto switched by plug insertion. Automatically switched socket-outlets such as these may be used to supply power to refrigerators, some computers and other accessories that normally should not be switched off. The absence of a user operable switch prevents the accidental switching off of such devices
Surface socket-outlet and plug. Australian Surface Socket-Outlet and Plug.jpg
Surface socket-outlet and plug.

Regulations require socket-outlets to be "individually controlled by a separate switch that .... operates in all active conductors", [10] subject to three "exceptions":

However, "stationary appliances" (such as fans) and most "luminaires" may be controlled by a remote switch, which would switch the supply via the socket-outlet concerned. Exceptions could be devices such as illuminated "Exit" signs, which require connection to the power supply at all times.

Each switch or means of operating a switch, for a socket-outlet shall be (a) as close as practicable to the socket-outlet, and (b) marked to indicate the socket-outlet(s) or the connected electrical equipment that it controls, with the exception that marking is not required where the socket-outlet controlled is obvious because of the location of the switch. [12]

Double pole switches are required in caravans and mobile homes:

Variants

Australian mains socket outlets for different current ratings. Starting with the basic 10 A socket outlet, the width of the Earth pin is first increased, the width of the Line and Neutral pins are then increased and the shape of the Earth pin is then changed, permitting only plugs of an equal or lesser current rating to be inserted into any socket outlet. Australian mains socket styles for different current ratings.jpg
Australian mains socket outlets for different current ratings. Starting with the basic 10 A socket outlet, the width of the Earth pin is first increased, the width of the Line and Neutral pins are then increased and the shape of the Earth pin is then changed, permitting only plugs of an equal or lesser current rating to be inserted into any socket outlet.
Comparison of 32 A (left) and 10 A (right) plugs. Australian 32 A vs 10 A mains plug.jpg
Comparison of 32 A (left) and 10 A (right) plugs.

Standard single phase 230 V domestic socket outlets in Australia and New Zealand are rated at 10 A.

However, for heavier duty applications there are several variants having current ratings of up to 32 A:

From this it may be seen that any plug can be inserted into a socket outlet of the same or higher rating but cannot be inserted into a socket outlet of lower rating.

Hence, a 10 A plug will fit into all of the five types of socket outlets, a 15 A plug will fit into all except a 10 A (and so on) while a 32 A plug will fit only into a 32 A socket outlet.

In general, only 10 A and 15 A socket outlets are likely to be encountered in domestic or commercial installations. Higher rated socket outlets are sometimes used for connection of electric ovens in domestic kitchens. These sockets are rarely seen in industrial environments, where AS/NZS 3123 weather-proof sockets are generally preferred.

A variant of the Australian standard 10 amperes plug has a socket on the back to allow connection of a second appliance to the same outlet. This type of plug is known officially as a "socket adapter plug" but is referred to colloquially, in Australia, as a "piggy-back plug", a "poofter-plug"[ citation needed ], or in New Zealand, as a "tap-on" plug. In Australia the plug is now available only as part of a pre-assembled extension cord, or by special order. In New Zealand rewirable PDL 940 "tap-on" plugs are more widely available.

Socket with a round earth pin Socket with round earth connector.jpg
Socket with a round earth pin

Other variants include plug/sockets with a rating of 10 A using a round earth pin, which is used on "special use" circuits, such as storage heaters in classrooms; and a 110 V 10 A version that has round active & neutral pins with a flat earth pin. The latter is rated at only 110 V (since certain [foreign] 110 V plugs could be inserted into the socket-outlet) and may be used on PAR 64 lights, where two 110 volt 1000 watt lamps are used in series. [15]

The active terminal is the first 'socket' from the Earth 'socket' in a clockwise direction when viewing the front of a socket-outlet. Care should be taken if Argentinian standards or faulty wiring swaps the active and neutral pins. Care should also be taken with the 10 A version with the round pin as physically compatible, but electrically incompatible NEMA 7–15 connector used for 277 V 15 A connections is encountered in commercial or industrial settings in the Americas. [16]

While never "codified", since the 1960s it has become "normal" for socket-outlets manufactured for use in Australia/New Zealand to have the Earth pin facing downwards, so that the longer Earth pin will be the last to lose contact if the inserted plug is tugged downwards. Many products such as "side-entry" plugs (with the cord exit in the 5 O'clock/135-degree position) and extra low voltage "plug packs" are manufactured for use in Australia/New Zealand assuming that the socket into which they will be inserted has the Earth pin downwards.

History

Now obsolete American 3 pin duplex socket-outlet Americanaussieoutlet.jpg
Now obsolete American 3 pin duplex socket-outlet

Australia's standard plug/socket system was originally codified as standard C112 (floated provisionally in 1937, and adopted as a formal standard in 1938). The Australian standard of 1937 was the result of a "gentlemen's agreement" between manufacturers Fred Cook of Ring-Grip, Geoffrey Gerard of Gerard Industries and Brian Harper Miller of the State Electricity Commission of Victoria (SECV). [17] The design was based on an American plug and socket-outlet intended for use at 120 V which was patented in 1916 under U.S. Patent 1,179,728 . [18] Australian plugs will fit these obsolete American outlets perfectly. (While this socket-outlet never became a NEMA standard design, the 50 A NEMA 10-50R, has a similar pin configuration in a larger form. [19] ) Argentina, Uruguay and China based their plugs and sockets on the same design. New Zealand also adopted the Australian design, since Australian equipment and many electrical appliances were exported to that country.

One of the reasons behind the adoption of that particular design was that it was cheap to make, with the flat pins being able to be easily stamped out of sheet brass, in contrast to round pins or thicker rectangular ones used in other countries. This was also a consideration when the Chinese authorities officially adopted the design in relatively recent times, despite the considerable inroads the British plug had made, because of its use in Hong Kong. The Chinese socket is normally mounted with the earth pin at the top. This is considered to offer some protection should a conductive object fall between the plug and the socket. [20] [21] The Chinese CPCS-CCC (Chinese 10 A/250 V) plugs and socket-outlets are almost identical, differing by only 1 mm longer pins [22] and installed "upside down". Though AS 3112 plugs will physically connect, they may not be electrically compatible to the Chinese 220 V standards. Originally there was no convention as to the direction of the earth pin. Often it was facing upwards, as socket-outlets in China now do but it could also be downwards or horizontal, in either direction. [23]

In Australia, the C112 standard was superseded by AS 3112 in 1990. A major update was released in 2000 as AS/NZS 3112:2000, which mandated active and neutral insulated pins [24] on the plugs sold for use with these socket-outlets after 3 April 2005, which somewhat negates any 'advantage' of having the earth pin uppermost. The standard AS/NZS 3112:2004 introduced more stringent testing procedures to test for bending of the pins and subtle changes to the radius of the pin tips. The current version is AS/NZS 3112:2011, Approval and test specification—Plugs and socket-outlets.

Voltage

In 1980, the International Electrotechnical Commission (IEC) rationalised the 220 V, 230 V and 240 V nominal voltage levels around the world to a consistent 230 V. This rationalisation was ostensibly made to improve the economics of making appliances by allowing manufacturers to produce a range of items with a rated voltage of 230 V. Not all countries have yet converted to the new standard.

The nominal voltage in most areas of Australia had been set at 240 V in 1926. In 2000, Standards Australia issued a system Standard AS60038, with 230 V as the nominal voltage with a +10% to –6% variation at the point of supply, i.e., 253 V to 216.2 V. A new power quality standard, AS61000.3.100, was released in 2011 [25] that details additional requirements. The new standard stipulates a nominal 230 V, and the allowable voltage to the customer's point of supply is, as mentioned, +10% to –6%. However, the preferred operating range is +6% to –2%. (244 V to 225 V). [26]

In Australia, the actual voltages delivered to customers is set at the state level. Most Australian states decided to transition to the 230 V standard, with some states choosing to remain at 240 V. As of 2019, all states have transitioned to 230 V, with the exception of Western Australia and Queensland. [6] Queensland began the transition to 230 V in 2017 and hopes to be completed to the "preferred range" by July 2020. [27] The reason given for Queensland's decision to move was the increased use of grid-tied rooftop solar installations raising the grid voltage. By lowering the voltage to 230 V, additional headroom of 960 megawatts was created to accommodate future residential power generation from rooftop solar. [27]

The voltage in New Zealand is also 230 V. In Fiji, Tonga and Papua New Guinea it is 240 V, and 220 V in the Solomon Islands. In China and Argentina the voltage is 220 V.

Brazil

In Brazil, this kind of plug is commonly found in high-power appliances like air conditioners, dishwashers, and household ovens. The reasons why they have been unofficially adopted for this use may be the robustness and high-current bearing capabilities, the impossibility of inverting phase (active) and neutral pins, or the fact that Argentina, a border country, uses this plug and used to be more developed than Brazil in the past so there may have been a flux of high-powered appliances from Argentina to Brazil at some point in time.[ citation needed ]

Nowadays, Brazil has adopted the national standard NBR 14136, which is loosely based on the IEC 60906-1 standard. NBR 14136 defines two types of socket-outlets and plugs: one for 10 A, with a 4 mm pin diameter, and another for 20 A, with a 4.8 mm pin diameter. New apparatus has been sold with the new plug, so the tendency is the usage of the "Australian" plug to fade away.

Related Research Articles

Power connector may refer to:

Mains electricity Type of lower-voltage electricity most commonly provided by utilities

Mains electricity is the general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to homes and businesses, and it is the form of electrical power that consumers use when they plug items such as domestic appliances, televisions and electric lamps into wall outlets.

IEC 60320 Appliance couplers for household and similar general purposes is a set of standards from the International Electrotechnical Commission (IEC) specifying non-locking appliance and interconnection couplers for connecting power supply cords to electrical appliances of voltage not exceeding 250 V (a.c.) and rated current not exceeding 16 A. Different types of connector are specified for different combinations of current, temperature and earthing requirements. Unlike IEC 60309 connectors, they are not coded for voltage; users must ensure that the voltage rating of the equipment is compatible with the mains supply.

Power cord power cable for connecting an appliance to a wall socket (including both captive and detachable cables)

A power cord, line cord, or mains cable is an electrical cable that temporarily connects an appliance to the mains electricity supply via a wall socket or extension cord. The terms are generally used for cables using a power plug to connect to a single-phase alternating current power source at the local line voltage—(generally 100 to 240 volts, depending on the location). The terms power cable, mains lead, flex or kettle lead are also used. A lamp cord is a light-weight, ungrounded, single-insulated two-wire cord used for small loads such as a table or floor lamp.

Schuko type of AC power plug and socket

"Schuko" is a registered trademark referring to a system of AC power plugs and sockets that is defined as "CEE 7/3" (sockets) and "CEE 7/4" (plugs). A Schuko plug features two round pins of 4.8 mm diameter for the line and neutral contacts, plus two flat contact areas on the top and bottom side of the plug for protective earth (ground). The socket has a predominantly circular recess which is 17.5 mm deep with two symmetrical round apertures and two earthing clips on the sides of the socket positioned to ensure that the earth is always engaged before live pin contact is made. Schuko plugs and sockets are symmetric AC connectors. They can be mated in two ways, therefore line can be connected to either pin of the appliance plug. As with most types of European sockets, Schuko sockets can accept Europlugs. Schuko plugs are considered a very safe design when used with Schuko sockets, but they can also mate with other sockets to give an unsafe result.

Residual-current device Electrical safety device used in household wiring

A residual-current device (RCD), or residual-current circuit breaker (RCCB), is a device that quickly breaks an electrical circuit to prevent serious harm from an ongoing electric shock. Injury may still occur in some cases, for example if a human falls after receiving a shock, or if the person touches both conductors at the same time.

AC power plugs and sockets connect electric equipment to the alternating current (AC) power supply in buildings and at other sites. Electrical plugs and sockets differ from one another in voltage and current rating, shape, size, and connector type. Different standard systems of plugs and sockets are used around the world.

IEC 60309 Standard for industrial and multi-phase sockets in Europe

IEC 60309 is a series of international standards from the International Electrotechnical Commission (IEC) for "plugs, socket-outlets and couplers for industrial purposes". The maximum voltage allowed by the standard is 1000 V DC or AC; the maximum current, 800 A; and the maximum frequency, 500 Hz. The ambient temperature range is −25 °C to 40 °C.

Mains electricity by country includes a list of countries and territories, with the plugs, voltages and frequencies they commonly use for providing electrical power to appliances, equipment, and lighting typically found in homes and offices. Some countries have more than one voltage available. For example, in North America most sockets are attached to a 120 V supply, but there is a 240 V supply available for large appliances. Often different sockets are mandated for different voltage or current levels.

Industrial and multiphase power plugs and sockets high-power AC electrical connector used for industrial and multiphase power supply

Industrial and multiphase plugs and sockets provide a connection to the electrical mains rated at higher voltages and currents than household plugs and sockets. They are generally used in polyphase systems, with high currents, or when protection from environmental hazards is required. Industrial outlets may have weatherproof covers, waterproofing sleeves, or may be interlocked with a switch to prevent accidental disconnection of an energized plug. Some types of connectors are approved for hazardous areas such as coal mines or petrochemical plants, where flammable gas may be present.

As the neutral point of an electrical supply system is often connected to earth ground, ground and neutral are closely related. Under certain conditions, a conductor used to connect to a system neutral is also used for grounding (earthing) of equipment and structures. Current carried on a grounding conductor can result in objectionable or dangerous voltages appearing on equipment enclosures, so the installation of grounding conductors and neutral conductors is carefully defined in electrical regulations. Where a neutral conductor is used also to connect equipment enclosures to earth, care must be taken that the neutral conductor never rises to a high voltage with respect to local ground.

Electrical wiring electrical installation of cabling and associated devices such as switches in a structure

Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure.

Electrical wiring in the United Kingdom is commonly understood to be an electrical installation for operation by end users within domestic, commercial, industrial, and other buildings, and also in special installations and locations, such as marinas or caravan parks. It does not normally cover the transmission of electrical power to them.

Europlug non-rewirable flat, two-pole domestic AC power plug

The Europlug is a flat, two-pole, round-pin domestic AC power plug, rated for voltages up to 250 V and currents up to 2.5 A. It is a compromise design intended to connect low-power Class II appliances safely to the many different forms of round-pin domestic power socket used across Europe. However, it is not compatible with the rectangular-pin BS 1363 sockets found in Cyprus, Gibraltar, Ireland, Malta and the United Kingdom. Europlugs are non-rewirable and must be supplied attached to a power cord.

IEC 60906-1 230 V AC connectors for domestic use

IEC 60906-1 is an international standard designed "to provide a standard for a safe, compact and practical 16 A 250 V AC system of plugs and socket-outlets that could be accepted by many countries as their national standard, even if not in the near future." The standard was originally published by the International Electrotechnical Commission in 1986; the current edition is ed2.0 published in 2009. Although it is almost identical to the Swiss SEV 1011 T12 plug for 10 A 250 V a.c. standardized in 1937, its dimensions are slightly different and its polarization is flipped. As of July 2014, only South Africa has introduced a standard based closely on IEC 60906-1. Brazil used it as the basis for its NBR 14136 standard, but this is not compatible with IEC 60906-1. In 2017 the European Union (EU) published recommendations advising against the harmonisation of domestic plug and socket systems in the EU.

NEMA connector type of power plugs standardized by the National Electrical Manufacturers Association

NEMA connectors are power plugs and receptacles used for AC mains electricity in North America and other countries that use the standards set by the US National Electrical Manufacturers Association. NEMA wiring devices are made in current ratings from 15 to 60 amperes (A), with voltage ratings from 125 to 600 volts (V). Different combinations of contact blade widths, shapes, orientation, and dimensions create non-interchangeable connectors that are unique for each combination of voltage, electric current carrying capacity, and grounding system.

Portable appliance testing procedure in which electrical appliances are routinely checked for safety

Portable appliance testing is the name of a process in the United Kingdom, the Republic of Ireland, New Zealand and Australia by which electrical appliances are routinely checked for safety. The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and any flexible cables for good condition, and also where required, verification of earthing (grounding) continuity, and a test of the soundness of insulation between the current carrying parts, and any exposed metal that may be touched. The formal limits for pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested.

Plugs and sockets for electrical appliances not hardwired to mains electricity originated in Britain in the 1880s and were initially two-pin designs. These were usually sold as a mating pair, but gradually de facto and then official standards arose to enable the interchange of compatible devices. British standards have proliferated throughout large parts of the former British Empire.

Plugs and sockets for portable appliances started becoming available in the 1880s. A proliferation of types developed to address the issues of convenience and protection from electric shock. Today there are approximately 20 types in common use around the world, and many obsolete socket types are still found in older buildings.

CEE 7 is a standard for alternating-current plugs and sockets. First published in 1951 by the former International Commission on the Rules for the Approval of Electrical Equipment (IECEE), it unified standards produced by several continental European countries. The 2nd edition was published in 1963 and last updated in March 1983. It remains available from the IEC, but they state that "this standard shall not be used alone, it is to be used in addition to IEC 60884-1".

References

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  3. 1 2 AS60038-2012 Standards AustraliaStandard Voltages
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  5. VOLTAGE & EQUIPMENT STANDARDS MISALIGNMENT
  6. 1 2 Energex - 230 volt transition (under the "Why did we do this?" FAQ entry)
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  12. AS/NZS 3000:2007 (Wiring Rules) - 4.4.4.3
  13. AS/NZS3001:2008 (Electrical Installations – Transportable structures and vehicles) - 3.6.2
  14. AS/NZS3001:2008 (Electrical Installations – Transportable structures and vehicles) - 3.6.3.1
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  27. 1 2 https://www.dnrme.qld.gov.au/energy/initiatives/statutory-voltage-limits