Museum of Plugs and Sockets logo, small IEC 60309 standard
plugs and sockets
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IEC 60309 (formerly IEC 309) is an international standard defined by the International Electrotechnical Commission for plugs, socket, outlets and couplers for industrial purposes.

IEC 60309 specifies a large range of sockets, plugs and connectors. Basic specifications and an overview of types are given on a separate page.

A relative small number of types are represented in the museum collection. Many others are beyond the scope of the museum.

The 16A types shown below are commonly used in Europe at campings, marinas, workshops and farms. They are rarely used for domestic purposes.

A 3-phase 400V rating refers to 380 to 415 Volt.


IEC60309socket3pin IEC 60309 3-pin coding
IEC60309plug3pin IEC 60309 16A 3-pin inlet

IEC 60309 5-pin coding
IEC60309plug5pin IEC 60309 16A 5-pin inlet

1 - 3
IEC 60309 16A - 230V single phase devices.
1: socket outlet;   2: plug; manufacturer of 1 and 2: JSL Material Eléctricos S.A., Portugal.
3: appliance inlet, manufacturer: ABL, Germany.
PE = protective earth. Plugs and inlets have a key and outlets have matching keyway. See image no. 13 for details.
200-250 Volt devices are (partially) blue; see basic information page for IEC 60309 colour coding.
4 - 6
IEC 60309 16A - 400V three-phase, 5-pin (30+N+PE) devices.
4: socket outlet, manufacturer: Mennekes, Germany.   5: plug, manufacturer: PC Electric, Austria.
6: appliance inlet, manufacturer: REV Ritter, Germany.
Image nos. 7 and 8 show a 4-pin (3p+PE) plug and connector. A variant of the 3-phase plug is shown in image nos. 14-19.

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 when a balanced load between L1, L2 and L3 is assured. A protective earth (PE) connection is standard on all IEC 60309 devices.
Manufacturer: ABL-SURSUM, Germany.
8 IEC 60309 400V, 16A 4-pin three-phase socket made in Poland by an unknown manufacturer.
9 16A Perilex plug wired to an IEC 60309 16A five-pole, three-phase connector plug. Manufacturers: Bals, Germany (CEE connector) and Insta (common subsidiary of Berker, Gira and Jung), Germany (Perilex plug).

IEC60309adapter3pin IEC60309adapter5pin

10 Adapter cable with CEE 7/7 (Schuko hybrid) plug and IEC 60309 16A - 230V single phase outlet. Manufacturer: PC Electric, Austria.
11 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. Manufacturer: Mennekes, Germany (CEE plug) and ABL (Schuko plug).

IEC 60309 380V 32A three-phase socket
IEC 360309 comparison of 6h and 9h socket

12 P17 32A 9h1 socket made by Legrand, rated at 127/220 V - 138/240 V. The socket is mainly used in North America for high leg delta wiring of split-phase electric power. It allows one to choose single-phase AC power at either 110-120 V between phase and neutral2, or 220-240 V between phase and phase3.
However, the shown socket has been used in Britain and was wired for two separate single-phase 240 V circuits: R1 – N and S2– T3, whereas T3 was wired as a second neutral connection, separate to the standard N.   {DF}

1 refers to position of earth contact, see image no. 13;    2 R1 – N  in image 13;
3 S2  – T3  (R, S and T are designations for L1, L2 and L3 used in former times).
13 An important feature of IEC 60309 devices is that for each type of plug there exists only one matching socket. Any potentially dangerous mis-connection is impossible because:
1. Plugs have a key (see nos 2, 5 and 9) that fits in a socket keyway; ergo, there is only one orientation in which a plug can be inserted. Socket keyways always have a down facing position.

2. Each plug has an earth pin, which has a larger diameter than the other pins. The position of the earth pin may differ between various types of plugs. Earth pin orientation is indicated according to clock hours. See IEC 60309 basic information for details.
Socket no. 12 is a 9h example; all others plugs and sockets on this page are 6h examples.

3. Size of plugs and matching sockets differs according to current (16A, 32A, 64A and occasionally 125A).


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

14 Extension cord with IEC 60309 16A five-pole, three-phase plug with phase inverter. See nos 16-19 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.
15 Preferred wire insulation colours according to IEC 60446 (2004). Wires of HTCN extension cable (no. 14) have these colours.
16, 17 Front view of plug no. 14. 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. 17. This is the standard IEC 60309 connection.
18, 19 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. 19. 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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