Museum of Plugs and Sockets logo, small CEI 23-50 standard
Italian plugs and sockets
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Comitato Elettrotecnico Italiano standard 23-50 plugs and sockets are used in Italy.
CEI 23-50 (first edition in 1995) has replaced the CEI 23-16 (1971) standard. Section VII of the standard relates to 10A and 16A plugs and sockets.
Compatible plugs and sockets plugs are used in Chile, Cuba, El Salvador, Ethiopia, Libya, Syria, Tunesia and Uruguay.
Type J profile Related galleries:
uncommon types
heavy duty types


VIMAR CEI 23-50 socket, 10A CEI 23-50 socket for 10A and 16A plugs Contacts of Italian 10A / 16A socket Italian 10A and 16A connectors, CEI 23-50
Italian 10A and 16A plugs, CEI 23-50 BTicino corner plugs, 10A BTicino corner plugs, 10A 16A CEI 23-50 adapter for 10A plugs

In the first half of the 20st century two voltages were commonly available in homes (at different tariffs): 110 Volt for „luce“ (light) and 220 Volt for „forza“ (power). Different plugs were used for 110 and 220 Volt to prevent incorrect connections: 10A plugs with 4.0 mm pins, 19 mm spacing for 110V and 16A plugs with 5.0 mm pins, 26 mm spabing for 220V (information given by Markus St÷llnberger).
Distinction in voltage does not exist anymore, in favor of 230V, but the difference between Italian 10A and 16A plugs still exist.

1 Classical example of a CEI 23-16 (now 23-50) standard 10A socket. The example shown is a VIMAR company, type SICURY socket. Sicury refers to a shutter that prevents accidental contact with power pins. Vimar was the first Italian company to offer this safety provision in 1968; details are shown below. Nowadays safety shutters are compulsory.   {SL}
2 Socket that can accommodate both 10A and 16A plugs (see no. 5). The right outlet has a bipasso or bivalente (dual use) figure of eight shaped slots. The larger (5.1 mm) diameter 16A slots have a 26 mm spacing; the smaller (4.5 mm) 10A slots have a 19 mm spacing, which is also suitable for Europlugs. Manufacturer: Bticino.
3 The Bipasso type socket no. 2 allows separate wiring of the 10A and 16A outlets. They can be connected to respectively a 10A and 16A fuse in the main fuse box of the house. However, it is also possible to interconnect the two connector blocs. 
Note that Italian CEI 23-50 plugs and sockets are not polarized, because of the symmetrical arrangement of the slots
. That means that the position of brown (line) and blue (neutral) wires can be swapped.
4 10A and 16A connector plugs. 16A models have 'dual use' shaped outlets. Manufacturer: Scame.
5 Italian 10A and 16A plug. It is compulsory that the basal part of power pins have insulated sleeves preventing accidental electric shock by not fully disconnected plugs. Pin diameter of 10A plugs is 4.0 mm; 16A plugs have 5.0 mm pins. Manufacturer: Scame.
6, 7
Examples of two models of 10A plugs. Plug pin position can be changed easily from top to side (compare top and bottom images). The thickness of both housings is only 15 mm. The disassembled model (see no. 7) shows the elegant simplicity of the design. These 'Corner' models are developed by the Italian Bticino company.
8 Adapter for making 16A sockets also accessible to 10A plugs. Manufacturer: SRS (abbreviation of an unknown company)

VIMAR sockets universale and bipresa
4Box socket with !0A, bipasso and Schuko outlets

4BOX 3 in 1 socket
4BOX 3 in 1 socket with 10A and 16A plug
4BOX 3 in 1 socket
4BOX 3 in 1 socket with Schuko plug

Italian multiplug for 10A, 16A and Schuko plugs

Italian grounding system differs from all other standards. Adapted sockets have been designed to bridge the compatibility gap between Schuko (CEE 7/4 and 7/7) plugs and typical Italian sockets. Examples made by VIMAR accept even more plug types. Multi-purpose type of sockets are becoming increasingly popular in newly build accommodations.

'Universale' socket for Italian 10A and 16A plugs (indicated with I), as well as Schuko (D) and NEMA 1-15P (USA) plugs. The diameter of the inner (10A) slots is larger than the 10A slots in sockets no. 10 otherwise it would be impossible to insert a Schuko plug (pin diameter 4.8 mm; spacing 19 mm). Manufacturer: VIMAR.   {WaO}

Two additional VIMAR "▀presa" sockets for Italian 10A and 16A plugs.
11 Socket with two 10A outlets (left and right), a bipasso outlet (center) and CEE 7/3 (Schuko) outlet.
The most common Italian wall box is type 503 that provides space for one, two or three upright 10A or 16A outlet modules. A Schuko outlet takes the space of two modules. The shown socket is a compact model that fits in a 503 box and offers two 10A and a socket outlet*. Manufacturer: 4Box, Milano, Italy. Dating 2023.
Note that the Vimar socket shown in images 9-10 requires a larger, non-standard,  wall box and wall plate.
* Information about Italian wall boxes has been given by Saluele Collodi.
12 3-way, 'triple use' multi-plug for Italian 10A and 16A plugs (top and side entries) and a Schuko plug (top entry only). Although this multi-plug is meant for a 10A outlet, it also allows 16A plugs (either CEI 23-50 or Schuko)*. Schuko plugs cannot be inserted in the two side entries, because of insufficiently large diameter of those 10A slots. Manufacturer: Scame.
* from 2014 it is no longer allowed to produce and sell 10A multi-plugs or adapters that accept also 16A plugs.
13- 16 4BOX socket that can be used for CEI 23-50 10A and 16A plugs, or a CEE 7/4 or 7/7 (Schuko / hybrid) plug; see respectively image no. 15 and 16. The two flexible earth clips - essential for Schuko plug earth contact - seems to hinder the insertion of Italian plugs (see image no. 14). However, an ingenious mechanism pushes the earth clips aside when a 10A or 16A plug is inserted. Up to two Europlugs can be inserted also.   {WeO}

Italian socket with Schuko adapter
Electraline asymmetric adapter for Schuko plugs
Italian socket with asymmetric adapter for Schuko plugs
Italian socket with plug and adapter for Schuko plugs

A CEE 7/4 adapter is needed if a home or office doesn't have universal type sockets (see nos. 10, 11, 13) and an appliance cord has a Schuko plug. When using a dual socket (identical to no. 2) the adapter makes the second outlet inaccessible.
To solve this inconvenience, the company Electraline has designed an asymmetrical adapter, see image 17b.
17b - d Asymmetrical adapter with 16A pins* and an outlet for a 16A Schuko plug or 10A Italian plug. Images 17c and 17d show that the other outlet of a dual socket remains accessible for a standard Italian 10A plug (identical to 10A plug in image no. 5).
Adapter manufacturer: Electraline 3Pmark S.p.A. in Concorezzo (MB), Italy.   {ARF}
* a variant with Italian 10A pins exists also.

CEI 23-50 10A 3-way multi-plug

CEI 23-50 16A 3-way multi-plug Plugs made of galatite

18 10A multi-plug with three 10A outlets. Manufacturer: Scame.
19 16A multi-plug with four 'dual use' outlets. Manufacturer: Scame.
20 Small plug (33.4 x 12.5 x 19.8 mm) designed for replacement of classic lamp cord plugs. The plug has been made of galalith, a synthetic plastic material, based on casein and formaldehyde. A block of galalith can be cut, drilled, carved and dyed. Because it is not possible to mould galalith, the plug has a simple, one piece body. Wiring has to be done by unscrewing the partially insulated pins. Any form of cord tension relief is not possible.
The Italian shop Punto Luce offers (2016) galalith plugs in four colors: marrone (chestnut brown), grigio (grey), oro (gold) and ivorro (ivory). Rating and manufacturer are not indicated. Plugs have no certification mark.   {MSt}

Porcelain bipasso socket

Adapter plug with locking mechanism
L'Automatika plug locking mechanism, details

21 White porcelain bipasso type earthed socket, rated at 10A/16A -250V.
Socket contacts are protected with black safety shutters. Manufacturers: Merlotti S.a.s. (porcelain design*) and Elios SpA (plastic inner part with contacts and shutters). Dating: 2010s.   {RH}

* Merlotti offers among others a range of cords with twisted textile insulation and porcelain electrical sockets, switches, lampholders that have a classic look but comply with modern standards.
Adapter with 10A-type pins and bipasso inlet. When the adapter is fully inserted in a socket or connector plug an internal mechanism locks the adapter. Image 22a shows external visible parts of plug locking mechanism. Details of the mechanism internal part are unknown. Pressing the big red button unlocks the adapter.
The adapter box states:
"With the Automatika your standard household plug is improved by adding an automatic expulsion feature!"
"With the Automatika, in case you're using a plug on an extension cord, you can simply push [the button] with your foot to eject the socket."

Manufacturer: L' Automatika S.r.l., Cabiate (Como).



Bticino not earthed 10A socket
Bticino not earthed 10A socket
Bticino not earthed 10A socket

Obsolete Italian 16A socket without earth AVE 10A socket and push button

24a, b
Obsolete type of not earthed 10A socket that was a part of the Bticino Domino series. The two brass contacts are kept in place in a small porcelain block that is fixed to the wall plate by a single screw (images 24a, b). A simple but effective design. Rating: 6A-250V AC or 10A-125V AC. The note "GARANTITO 5 ANNI - 1956" suggests that guarantee ended in 1961.
The Bticino logo used at that time is shown in image no. 28.   {WN}
25 Obsolete type 16A socket without earth. It was part of the Btichino Piuma series that was produced from the mid 1950s to late 1970s. Manufacturer: Btichino.   {SL}
26 Recessed 10A socket and push button. The button is missing in the museum collection socket (left). An example of the push button is copied from an ebay images (right). Such sockets could be found in hallways and were used to open the front gate of a house or door of an apartment. A dual purpose socket saved the construction of a second connectionm.
Before the ntroduction of plug pins with insulated sleeves, recessed outlets were a safe option, but they have never been used at a large scale.
Manufacturer: AVE (Anonima Vestonese Elettrica). Dating 1960s-'70s).
Information about the combination of outlet and push button has been given bij Samuele Collodi

ETF not earthed 2-way multi plug
ETF not earthed 2-way multi plug
ETFnot earthed 2-way multi plug, inside
BTicino and TGM logos

27a, b
Adapter plug with two outlets. Rating: 110 - 220V / 200-W. The inside (image no. 25b) explains the very low capacity of 200 Watt. The adapter is meant for festoons of intermittent decoration lights; for example in a Christmas tree. The higher the wattage the faster lights are switched on and off.
The adapter is patented (brevettato) by an unknown and probably no longer existing Italian company ETF. Another unknown, TGM logo has been found at the inside, see image no. 26.   {WN}
28 Top: Bticino logo found on socket nos 24 ad 25. It was introcuced in 1974 when the company name changed to Bassani Ticino.
Bottom: Unknown TGM logo found inside the ETF adapter plug no. 25. T.G.M. S.r.l. is an Italian manufacturer of electric cables, founded in 1986. It is questionable whether the adapter TGM is the same as cable supplier.

Vimar Sicury plug

Figure right shows Vimar's patent 61549, granted on March 15 1968.
The patented
mechanism closes automatically access to socket contacts when a plug is pulled out.

When plug is inserted:
plug pins rotate shutter no. 2 and contacts are accessible.

When plug is pulled out:
spring no. 3 brings shutter back in position that blocks access to contacts.

Vimar 10A socket shown in above image no. 1 has this type of safety shutter.

Source: Vimar history.
Figure from Vimar's patent 61549


Logos of Italian manufacturers of material shown on this page
Logos of Italian manufacturers
Details of companies are given in list of Italian manufacturers


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