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IEC 60309 (formerly IEC 309) is an international standard from the International Electrotechnical Commission for plugs, socket-outlets and couplers for industrial purposes.
IEC 60309-2 specifies a range of mains power connectors with circular housings, and different numbers and arrangements of pins for different applications.

The following colour coding is used: yellow = 100-130V; blue = 200-250V; red = 380-480V. Purple and white housings are used for less than 100V, while black and green are reserved for 500V and up and frequencies exceeding 60 Hz.

IEC 60309-2 variants are designed so that a plug of one type can only be inserted into a socket of the same type. Different current ratings are distinguished by different diameters of the circular housing.

The 16A single and three-phase variants below are commonly used in Europe at campings, marinas, workshops and farms.
They are rarely used for indoor domestic purposes.

In the UK the IEC 309 standard was adopted as BS 4343 in 1968, and in 1999 replaced by the European equivalent BS EN 60309.
In Britain these heavy duty plugs are often referred to as CEE plugs or Commando plugs (refers to the MK Electric company Commando range of connectors).


IEC60309socket3pin IEC60309plug3pin IEC60309code3pin

IEC60309plug5pin IEC60309code5pin

1 IEC 60309 230V, 16A single phase wall socket.
2 IEC 60309 230V, 16A single phase plug. The coding of the pins is shown at right; PE = Protective Earth
3 IEC 60309 230V, 16A single phase outlet to Schuko plug adapter.
4 IEC 60309 230V/400V, 16A three-phase wall socket.
5 IEC 60309 230V/400V, 16A three-phase plug and pin coding. The preferred wire insulation colours according to IEC 60446 (2004) standard are shown in image no. 11. A variant of this plug is shown in image nos 10, 12-15.
6 IEC 60309 16A plug wired to a Schuko connector plug. Only L1, N and PE poles are wired up. The PE pin is connected to the Schuko earth clips.


IEC 60309 16A 4-pin plug IEC 60309 16A 4-pin socket made in Poland
IEC60309-Perilex adapter coird

7 IEC 60309 400V, 16A 4-pin three-phase plug. A connection without neutral pole can be used for three-phase electric motors, because a balanced load between L1, L2 and L3 is assured. For safety there is always a protective earth (PE) connection.
8 IEC 60309 380V, 16A 6h 4-pin three-phase socket made in Poland. Plug no. 7 fits in the Polish IEC socket. The indication of 6h refers to the position of the earth pin, which is at 6 o'clock (identical to socket nos. 1 and 4).
9 16A Perilex plug wired to an IEC 60309 16A five-pole, three-phase connector plug.


HTCN IEC 60309 plug
HTCN IEC 60309 plug_1
HTCN IEC 60309 plug_3
IEC 60309 plug, inside  with colour coding
HTCN IEC 60309 plug_2
HTCN IEC 60309 plug_4

10 Extension cord with IEC 60309 16A five-pole, three-phase plug with phase inverter. See nos 12-15 for explanation. The connector at the other end of cable is a standard IEC 60309 plug, essentially identical to socket no. 4.
Certificates: CE and Semco (Sweden). Manufacturer: Hengtong Electrical Co., China. Plug type HTN715.
11 Preferred wire insulation colours according to IEC 60446 (2004). Wires of HTCN extension cable (no. 10) have these colours.
12, 13 Front view of plug no. 10. L2 and L3 pins are mounted in a revolving selector wheel. When plugged in, the parallel orientation of the selector wheel results in connecting L2 pin with the black (L2) wire and L3 pin with the grey wire of the extension cable; see image no. 13. This is the standard IEC 60309 connection.
14, 15 With a screw driver the revolving selector wheel has been rotated 180. The grey wire is now connected to the L2 pole of a IEC 60309 socket and the black wire to the L3 pole; see image no. 15. The phase inversion (L1-L2-L3 becomes L1-L3-L2) results in a reversed direction of rotation of a three-phase electro motor connected to the extension cord. Change of rotation direction can be achieved without rewiring, which would require dismantlement of motor or plug.


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