IEC 60309

63 A plug with pilot contact

Connectors rated at 63 A and 125 A may optionally be equipped with a 6 mm pilot contact. This smaller pin in the centre of the connector is shorter than the others, designed to 'make' after all the other pins when connecting a plug and socket, and to 'break' first when disconnecting. It is used to switch off the load. This is useful as disconnecting under load will cause arcing which may cause damage to both the plug and socket, and risk injury to the user.

The pilot pin is located in the centre of main contact circle on 4- and 5-pin connectors. On 3-pin (2P+E) connectors, it is located on the contact circle opposite the ground pin. The other connectors are located 105° on either side of the earth pin, rather than 120° as in the smaller variants, to make room for the pilot pin.

The standard specifies an additional, different design for extra-low voltages up to 50 VAC and currents of 16 or 32 A. This resembles, but is larger than, the IEC 60906 DC connector.

Low-voltage compatibility

		Plug
		16/20 A	32/30A
Socket	16/20 A
	32/30 A

On the male plug, three 6 mm pins each 20.5 mm long are equally spaced around a 15.4 mm diameter circle, starting at the 12-o'clock position. They are surrounded by a 23 mm long shroud with an inner diameter of 36 mm and an outer diameter of 42 mm. The pin opposite the major key is optional and may be omitted to make a 2-pin variant. The inner surface of the male plug shroud is flattened at the 6-o'clock position. One or two grooves are cut in the male plug shroud to mate with corresponding keys in the female socket. There is a required major groove at the 6-o'clock position and an optional minor groove at the 12-o'clock position.

24 V, 16 A, 2P, 50/60 Hz: violet connectors (no minor key)

Socket

Plug

On the female socket, the major key is 4 mm deep at the 6-o'clock position. The width of the major key defines the current rating: 32 A plugs have a narrower 5 mm wide groove, while 16 A plugs have a wider 8 mm groove, and therefore 32 A plugs can be used with 16 A sockets but 16 A plugs cannot be used with 32 A sockets. The optional minor keyway is the same dimension for both current ratings: 4 mm wide at the 12-o'clock position, which mates with an additional 5 mm wide groove cut through the shroud.

32 A 400 V 3P+N+E 6h (180°) plug

16 A 400 V 3P+E 6h plug

The red 3P+N+E, 6h (180°) plug allows connecting to the widespread 400 V three phase power network. The most common ratings are 16 A, 32 A and 63 A, with 125 A less common. Construction sites in central Europe have most of their higher power cabling setup with this three phase socket type as the single phase to neutral voltage of 230 V is available for other devices. So called power splitters with this connector as a 3 phase inlet and 3 groups of single phase outputs with individual circuit breakers are generally used to achieve this, and allow load balancing across the phases, important on generator supplies. Similar configurations are used for outdoor exhibitions, festivals and large events.

When looking at the mating face of the socket, the phase sequence should be L1, L2, L3, and then the neutral pin, proceeding clockwise from the earth pin. (Counter-clockwise on the corresponding plug.) Since some wiring may be reversed, which would make motors turn backward, many machines on construction sites feature a phase swap plug that allows the L2 and L3 phase pins to be swapped, thereby reversing the phase sequence.

Three-phase electric motors do not need the neutral wire to function, so that there is also a red four pin variant (3 phases and earth) of the IEC 60309 plugs for three phase power. The two styles are not intermatable, to prevent a potential floating neutral.

16 A 230 V P+N+E 6h socket

The blue P+N+E, 6h (180°) plug is a single phase connector. In particular the smallest (16 A) weather-resistant variant has become especially common in camping vehicles and sockets found in caravan parks and marinas throughout Europe.[10] The so-called 'Caravan Mains Socket' has almost universally replaced a wide variety of other national 230 V domestic plugs,[11] since it is pan-European and inherently safe to standard IP44. On larger temporary buildings, particularly with electric heating, the larger 32 A is more common.

The pins are specified to be in the order earth, phase, and neutral, clockwise when looking at the socket. Not all installations distinguish the line (phase) and neutral conductors, and reverse wired sockets are not uncommon, so double pole breaking RCDs and main switches are recommended. When sockets are mounted looking downwards then the connector system is rated for outdoor use in all weather. This is also the standard connector for lighting equipment (up to 16 A) used in the British film and television industry (often as outlets from a power splitter with a higher rated 3 phase input).

The yellow P+N+E, 4h (120°) plug is a single phase connector that is in widespread use on the British Isles for 110 V building site and fairground applications. A popular model of this socket type is marketed under the brand name MK Commando[12] which leads some users to refer to all IEC 60309 sockets by the generic trademark Commando sockets.

The blue 3P+N+E, 9h (270°) plug is a three phase connector available in areas with both 115 V and 230 V supply systems (mains). It is prevalent in the outdoor event lighting and audio power industry as an outdoor-safe replacement for NEMA connectors. In the United States it is not usually used for three phase power but for the high leg delta wiring of split-phase electric power (unknown in Europe). This allows one to choose single-phase AC power at either 110–120 volts between phase and neutral or 220–240 volts between phase and phase. Since these two modes do not need three phases there is also a dark yellow-orange four-pin connector available designed for a single-phase 110–120 or 220–240 volt load.

It is best to connect the high leg adjacent to the earth pin, so that it will not be misplaced by phase-swap plugs.