three-phase plugs and sockets
are a variety of three-phase plugs and sockets that dates back to the
1930s to 1970s, when standardisation was limited. Some models were
probably not nationwide used on a large scale, but mainly appliance
specific in workshops.
Nos. 1 - 7, as well as nos. 19 and 13 resembles classic Italian heavy duty types, but French and Italian models are not identical.
Pin spacing is different, therefore French plugs does not fit in comparable Italian sockets and the other way round.
|1, 5, 8||Three-phase,
3-pole (3xL) sockets and plug rated at 15A-380V (socket) / 20A-250V
absence of a neutral pole indicates that they could be used only when a
balanced load between the three line poles was assured, for example to
power a three-phase electric motor. Socket nos. 1 and 2 have a
and Duroplast housing. No. 8 is an older, fully porcelain
Each of models belong to the B223 series, produced by the Legrand company.
|2, 4, 6||Three-phase,
4-pole (3xL+N or earth) models of the Legrand series B223 (nos. 2
and 6) and
a comparable socket with a more luxury nickel alloy plated design.
The three power pins are 20 mm long and have a diameter of 4 mm. The
central pin is 5 mm in diameter and is 4 mm longer than the power pins.
The thickness and length of the central pin seems to make it more
likely that it is a protective earth pin rather than neutral connector.
The three power pins are positioned in an equilateral triangle with sides (center to center) of 23 mm. The centrally positioned pin has an offset (measured from one of the sides) of 8.5 mm.
The manufacturer of no. 4 is unknown, but it could be Electro Sécurit (taken over in 1956 by Legrand). Similar, single-phase nickel plated sockets are made by Electro Sécurit (see classic domestic examples). The socket has number A223; another link with Legrand.
3-pin model in the Legrand B223 series. Rated at 15A-380V /
It is unclear how the three-pin plugs was used. It could have been used as an earthed single-phase plug, but that required a different wiring of the corresponding socket no. 2.
Another, less likely, option is deriving two-phase power from a three-phase source, but that requires an additional Scott three-phase transformer to obtain two phases 90 degrees apart in time (instead of 120 degrees phase rotation in a three-phase circuit), and consequently a different wiring of socket no. 2.
Possibly there is still another explanation that doesn't require rewiring the socket, which would be much safer.
|9, 13||Three-phase, 4-pin
socket and plug rated at 25A - 433V AC (= √3 x 250), or 25 - 250V
DC. The socket
has a porcelain body. Wall plate and plug are made of Duroplast.
Three round power pins are 22 mm long and have a diameter of 6 mm. The
earth pin is 26 mm long and 8 mm
wide. Pin spacing is 15 mm.
Brand name: Legrand, indicated by a 1925-1967 type logo (see image no. 24).
〉 The right round pin of plug no. 14 was missing. Duroplast was locally melted by severe overheating. The image has been restored in Photoshop. 〈
|10, 14||Three-phase, 4-pin
socket and plug rated at 25A - 380V AC (= √3 x 220), or 25A -
250V DC. The three flat power pins are 24 mm long and 7 mm wide. The
round earth pin is 28 mm long and has a diameter of 5 mm. Pin spacing
is 14 mm. The smaller image below the procelain socket shows the partly
painted metal wall plate.
Plug and socket resemble nos. 9 and 13, but the types of power pins and earth pin are reversed.
Remarkably, nos. 10 and 14 do not have any indication to trace the manufacturer of the devices.
Nos. 9/13 and 10/14 were often used in kitchens for electric stoves and ovens and in bathrooms for electric oil-filled heaters.
4-pin socket and plug rated at 30A - 380V. The porcelain socket has a
nickel alloy plate. Bakelite plug. Power pins have a length of 29 mm
and diameter of 6.9 mm. Earth pin measures respectively 33 and 7 mm.
Brand name: Legrand, indicated by 1925-1967 type logo (see image no. 24).
||Three-phase, 4-pin socket and plug, rated at 10A - 250V. Pins are 19 mm long. Three pins have a diameter of 5 mm. The fourth, presumably earth pin is 6 mm in diameter. Socket is made of a solid rubber-like material. Bakelite plug. Brand name: Vynckier, a Belgian electrotechnical company established in 1937 (see image no. 24c for logo).|
socket rated at 10A - 250V. Contacts and fuses become visible after
removal of parts of the housing (see image no. 17). There are three 10A
fuses, one for each phase. Image no 20 shows a single fuse.
Manufacturer of socket, fuses and plug was the French company Cehess Soremec, which was based in Rungis, near Paris. They used the logo depicted in image no. 20b.
- 250V plug that matches with socket no. 16/17. The three line pins
have a length of 20.5 - 21.2 mm and a diameter of 5 mm. The
flat pin has a width of 7 mm and is 23.8 mm long.
The 10A fuse has 16.5 mm long pins that have a diameter of 7 mm. Fuse pin separation is 20.2 mm.
duplex fuse holder made by Legrand (series 23000), probably made in the
1970s. The fuse holder is meant for the same type of fuses as used in Cehess Soremec 10A-250V
socket (no. 17/18).
|21||Three-phase socket of unknown rating. No matching plug. The porcelain body of the socket shows an EP logo (see image 24d). It is unknown which manufacturer has used the logo.|
plug, rated at 15A - 250V. Three line pins have a diameter of 5 mm.
Earth pin is 4 mm longer than line pins and has diameter of 6 mm.
Manufacturer: L'Ébénoïd. The
company used an elephant as logo, see image 24b. Dating: probably
pin plug, rated at 16A-380V AC and 16A-250V DC. Pins are 22 mm long and
have a diameter of 6 mm. Pin spacing: 23 mm. Manufacturer: Legrand. Dating:
of the manufacturers of the plugs and sockets shown above.
• The first three are consecutive logos of Legrand. Electro Sécurit has been taken over in 1956 by Legrand.
• Cehess Soremec was most of all known for producing fuses. The company does not exist anymore.
• L'Ébénoïd, founded in 1937, now based in Saint Priest (67, France), is from 2001 a part of the Asea Brown Boveri group.
• Vynckier Frères & Co.(Gent, Belgium) was established in 1937 and later became a part of General Electric (USA).
• Logo 'd' has been used by an unknown company. Please contact me if you recognize the EP logo.
Find the museum address at the Home page page.
|D i g i t a l M u s e u m o f||P l u g s a n d S o c k e t s|