Three-phase sockets

Three-phase power outlet - a reception of the plug-in connector, designed for three-phase industrial networks. In everyday life, almost do not apply. Periodically elite class housing, and so forth. equipped with three phases. Typically, these sockets show protection against incorrect connection.

historical background

The design with the history position

Independent sources reported that three-phase socket design has changed little since the end of the XIX century. In 1904 at the World Fair in St. Louis became apparent the need for unification of various structures. Electric current was considered a relatively new phenomenon, abundance frequency voltage, technical solutions staggering. Incompatibility of systems has blocked access to foreign markets for local producers. The exhibition in the pavilion Electricity demonstrated abundance classes voltages and presence of multiple phases:

1. Edison promoted direct current one, two or more wires.
2. Nikola Tesla introduced into use two-phase 110 V 60 Hz.
3. Dolivo-Dobrovolsky invented the three-phase system, the ruling today.

June 26, 1906 was formed IEC - International Electrotechnical Commission. It all started with the Paris International Electrical Congress in 1900, where many countries were involved. Between the other - the United States and the United Kingdom. IEC standardization bodies, including the unit of measurement. This organization pioneered the introduction of the SI and engaged. It has fixed at the legislative level for the unit of measurement:

• Gauss.
• Hertz.
• Weber.

SI Fundamentals laid Giovanni Giorgi, in 1901, reported to the scientific community about the need to expand the ISS (Meter-kilogram-second) of the fourth value, serves as the basis for expansion of the system to the phenomena electromagnetism. The military situation of the first half of the XX century has been much delayed decision only in 1946 officially entered as missing several amperes. SI adopted in 1960.

The war dragged on and the development of plug-in connector standards. For example, household devices embodiments only released closer to the 20-th year. In the early 30 IEC members have adopted the experience of the Dutch organization IFK. They saw that the standardization of plug connectors brings additional benefits in international cooperation. Appointed large-scale trials, involving electricians from 12 countries.

Meeting in Paris (January 1933) led to results that IEC members decided to establish business relations with IFK to share experiences. Already in the new year, the Technical Committee (TC 23) turned out to be a collaborative effort. The tasks of the organization included the standardization of connectors and electrical connections for different purposes. It is not difficult to guess that Hitler's rise to power, troubled Europe, was not up to the socket.

As a result, the meeting was held. The June heat in 1938 came in Torquay (United Kingdom) with the IEC delegates. Then, a similar event took place in Paris a year later. Before the conquest of France remained a matter of months. Finally decided that the members of the TC 23 will be engaged immediately sockets and plugs. Hitler stayed with own opinion. June 22, 1940, France surrendered, Vichy regime were no longer needed sockets and plugs.

The first post-war years went to the reconstruction of the country damaged the economy. And then TC 23 engaged in household electrical outlets and plugs. Not to be confused with a similar unit that exists within the ISO organization. There are engaged tractors for agriculture and logging. Viewed TC 23 aims to develop electrical interfaces and cables (see. screen). For example, the industrial connectors engaged TC 23H department, and municipal - TC 23B.

The postwar years

In October 1947, representatives of the IEC was chosen for the collection of the city of Lucerne in Switzerland. At the helm were the guys from CEE (1946), and TC 23 remained in the wings (merging institutions occurred in 1985). We regret to inform you that it was not possible to find out the exact dates. What is clear is that the current version of the standard IEC 60309 conducts the family tree from 1979. First there were other documents allegedly CEE and IEC 17 309, which can not find evidence other than the fact of existence. In 1968 he published British Standard BS4343, relying on the mentioned.

It is known that initially the least commissioners think about security. In the foreground stood electrical equipment compatibility. BS4343 British Standard are the benefits of taking into account the specific security measures. Obvious advantages of the document demonstrated the CENELEC, and led to a revision of IEC documents adopted earlier. Thus were born two modern standard industrial plug connectors:

1. IEC 60309-1.
2. IEC 60390-2.

Both moved in British law as a BS EN60309-21BS4343, but much later, in 1992. Today the British technique is compatible with European products. Publication CEE 17 normalizes industrial variety of plug connections with a voltage up to 750 V and current of up to 200 A.

In North America and now found an incredible number of species of three-phase sockets, it is necessary even to produce special guidelines for their recognition. As part of NEMA Standards 150 subtypes exist detachable AC connectors.

Standard IEC 60309

Today, standard three-phase outlet for industry to include powered devices demands less than 750 V, current of 200 A and a frequency of 500 Hz. With an operating temperature of minus 25 to 40 degrees Celsius. As a rule, the body is carried out with a degree of protection IP44 or IP67 for moisture-resistant. Connectors are color coded, allowing to judge about the appointment:

1. Yellow - for frequencies 50 Hz and 60 Hz voltage 100-130 V.
2. Purple - the same way, the voltage of 20-25 V.
3. White - similarly, the voltage of 40-50 V.
4. Blue - for the previous frequency voltage of 200 - 250 V.
5. Orange - 125 or 250 V.
6. Red - for the same frequency, voltage 380 - 480 V.
7. Black - the former frequency indicators for voltage 500 - 690 V.
8. Gray - 277 V, 2 pole.
9. Green - high frequency, greater than 50 V.

Already in color often judged on the appointment and avoid common errors. Additional information comes from the position (clockwise) ground contact. Degree is measured from the side opposite the semi-circular ledge on the outer perimeter of the plug. The grounding pin is the thick, on this basis, and is. Lines usually 4 or 5. The researchers present data on the basis of the history of the three-phase sockets:

1. Three-phase isolated neutral on three pins. Today it is not used, are obsolete.
2. Three-phase isolated neutral and grounding contact pin 4. Encountered in the industry, standardized IEC 60309 standard.
3. Three-phase with neutral gluhozazemlonnoy without a protective grounding pin 4. Obsolete, do not apply.
4. Three-phase with neutral and earth gluhozazemlonnoy 5 pins. Described mainly by IEC 60309, are used in large quantities.

Sockets available in IEC 60309 standard ratings currents - 16, 32, 63 and 125 A. To ensure protection against incorrect connections are not only key provisions more thick grounding terminal, but vary the sizes of sockets and plugs (socket diameters, pins and etc.). It is impossible to physically connect the equipment to a different frequency or at a different voltage. On the screen are shown the variety of three-phase IEC socket and a two-phase, which is difficult to confuse. This ensures the protection of networks and equipment.

In three-phase outlets, as shown on the screenshot, the ground contact is in the region of 6 hours at the bottom. To be sure, marked black and visually - thicker than others. Two types of connectors described above, and the two-phase is used to connect the corresponding type electric cookers. Among household appliances such equipment is rare. IEC 60309 describes the sockets on the two phases of the four contacts, where more neutral short and fine, is offset by the other corner. Permissible to mix in appearance, properly connect all the same will not work, plus the color is different.

Location of keys on the socket IEC 60309

Consolidated list allows you to quickly identify the purpose of a particular two-phase or three-phase sockets (hours are counted on the frontal view):

1. Yellow. The grounding pin for 4 hours. Voltage 100 - 130 V.
2. Orange. The grounding pin 12 h (top). Voltage 120 - 240 V.
3. Blue. The grounding pin to 6 hours (bottom). Voltage 200 - 250 V.
4. Blue. The grounding pin for 9 hours. Voltage 120 - 250 V.
5. Purple - DC.
6. White - DC.
7. Gray. The grounding pin to 5 hours. Voltage 227 V, 60 Hz frequency.
8. Red. The grounding pin for 3 hours. Voltage of 380 V, 50 Hz.
9. Red. The grounding pin for 6 hours. Voltage 380 - 480 V.
10. Red. The grounding pin 11 hours. Voltage 380 - 480 V, 60 Hz.
11. Red. The grounding pin for 9 hours. Voltage 380 - 415 V.
12. Red. The grounding pin for 3 hours. Voltage 440 V, 60 Hz.
13. The black. The grounding pin for 7 hours. Voltage 480 - 500 V.
14. The black. The grounding pin to 5 hours. Voltage 500 - 690 V.
15. Green. The grounding pin 10 hours. Frequency 100 - 300 Hz.
16. Green. The grounding pin 2 hours. Frequency 300 - 500 Hz.
17. Gray. The grounding pin 12 hours. To supply through an isolation transformer.
18. Gray. The grounding pin for 1 hour. It is generally used for applications that do not fall within the specified earlier.

According to this list blue phase connector 2, shown in the figure, it is designed to work in circuits 200 - 250 (standard line voltage). In addition, there are described three-phase outlet 6 for switching pins at startup star- (which reduces inrush current). Sometimes a central connector is inserted pilot contact points shorter. He first comes out of the outlet when the latter comes off and when turned on. Pilot contact allows you to control the power supply, eliminating the arcing in the circuits 63 and 125 A. Advance and cutting out a little late including energy supply, this connector provides the best security.

On the screen shows a summary of all the currently existing three-phase sockets. Unnecessary options from the standard are missing or crossed out. Systems with gluhozazemlonnoy neutral marked marking "phase / line voltage." Their values ​​are different to the root of three times. In other cases, by a fraction of said linear voltage systems with isolated neutral. Then the values ​​are different numbers on the other factor. This feature will help readers to understand where and how the system is used.

We must not forget that on the socket contacts the image is reversed. If you look closely, it is clear that the confusion is only possible for the green connectors high-frequency voltage. In both cases, a 4-wire and ground connections are mirrored. However, if a recognition error may occur, incorrect connection is still possible, which achieved the standard developers.

In addition to the IEC sockets are known and others, but they are gradually being replaced. Consequently, a significant role is not played.