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Heavy duty plugs and sockets
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Switzerland has two types of earthed, domestic single phase plugs: 10A T12 (see image right) and 16A T23. Derived 3-phase plugs are respectively T15 (10A) and T25 (16A). See images 1-6.
A scheme shows the compatibility between 10A and 16A plugs and sockets.

Images 7-24 show examples of out of date 380V and 500 Volt plugs and sockets.

In the 1930s domestic earthed sockets had an earth pin. That applied also to single phase 380V devices. Transition sockets have been designed to facilitate the change of earth pin position from socket to plug in the early 1950s. Image 8 show an example.
CH_standard 10A plug


CH-10A 3phase socket Swiss T15 10A 3phase connector CH-16A 3phase socket

CH-10A 3phase plug Swiss Resista model T15 plug CH-16A 3phase plug

1, 4 10A - 230/400V three-phase socket and plug (SN441011 type 15). A guide (green arrow) prevents attempts to insert a five-pin plug (see no. 4) upside down. 10A T15 plugs can also be used with 16A T25 sockets (no. 3).
Manufacturers: socket: Feller AG in Horgen (ZH); plug: Electro-Mica AG im Mollis (GL).
2 10A - 230/400V three-phase T15 connector plug. Indicated L1, L2, L3, N, E configuration applies also to image no. 3 (16A).
WAROB, trademark of PWFG Kunststofftechnik in Laupersdorf (SO).
5 Resista model 230/400V, 10A three-phase T15 plug. The plug has a rubber, water resistant housing.
Manufacturer: Resista Electric SA in Renens (VD), Switzerland.   {FSE}
3, 6 16A - 230/400V three-phase socket and plug (SN441011  T25). A T25 plug does not fit in a 10A T15 socket.
Manufacturers: socket: Feller AG in Horgen (ZH); plug: Martin Kaiser in Hochstadt am Main, Germany

Compatibility of Swiss plugs and sockets.

The scheme right shows the compatibility of single phase plugs (T11, T12 and T23), three-phase plugs
(T15 and T25) and the four maching sockets.

T11 and  T12 (10A) plugs fit not only in 10A and 16A single phase sockets, but also in three-phase 10A and 16A sockets.

T23 (16A) plugs fit in two types of sockets: single and three-phase 16A.

T15 (10A) fits in 10A and 16A three-phase sockets

T25 (16A) fits only in 16A three-phase sockets.

Swiss plug - socket compatibility


Classic types

In the past Switzerland had an interesting variety of 380 - 500 Volt plugs and sockets. None of the examples shown below are for sale anymore.
T15 and T25 (see above) have replaced old 10A-380V T4, T5, T18 and T19 (see below)
For 400-500V industrial application Switzerland switched to IEC 60309 types. However, as long as old sockets and plugs still meet Swiss safety regulations, there is no need for replacement.

Several sockets, donated by Piet de Vaere, still had short parts of the original wiring (image right}. Formerly used often were red (line), yellow (neutral) and yellow/red (earth). Green was used for cord from switch to application. White and black possibly for L2 / L3. Brown - now standard L1 color - has not been found on the classic sockets.

Cord colours found on Swiss sockets


Position of earth pin

Early Swiss domestic, earthed sockets had a pin for protective earth connection. Two 10A single phase types have been introduced in the 1930s: T2 (250V) and T4 (380V).
The socket earth pin system has been abandoned in 1953, in favour of earth pin plugs.

From 1953 until 1974 transition type sockets were available that accepted both old and new style plugs: T14 for 10A 250V
and T20 for 10A 380V. Old T4 and new T18 plugs fit in T20 sockets, see scheme right and sockets and plugs below.

Swiss T4, T18, T19 and T20 schemes

Swiss T4 socket
Swiuss T20 socket
Swiss T20 socket, inside view
CH T18 plug made by Baillod

Swiss T18 connector plug
Swiss T18 plug
Missing in collection
T4 plug
Please contact me
if you can help me.
Find museum address on
start page

7 Porcelain 10A - 380V T4* socket meant for domestic use. According to "Elektrizität und Bauen" (Manual for builders, published by the Swiss Society for Electricity Management, Zürich, 1940) T4 sockets and plugs were used for applications charged according a special tariff.  Manufacturer: Adolf Feller AG in Horgen. Dating: 1930s.   {PdV}

* T3, 10A - 380V variant without earth connection have existed also. New, hexagonal style T3 plugs have not existed.
8, 9
When earthed T4 plugs and sockets were replaced by T18 plugs and T19 sockets, a "transition" T20 socket was introduced that accepts both old T4 and new T18 plugs. T20 sockets were available until 1975. The inner part of the T20 socket is shown in image 22b. Manufacturer: Adolf Feller AG in Horgen.   {PdV}
10 T18 three-pin plug for appliance cord, rated at 10A - 380V. Manufacturer: F. Baillod S.A., Chaux-de-Fonds (NE).
11,12 T19 connector (no. 17) and matching T18 plug (no. 18). Rating 10A - 380V. Both have a SEV certification mark (S+ type, introduced in 2002) and logos of companies Tschudin & Heid  AG and Feller AG. Both companies have for some time coordinated their plug production.    {ARF}

In the 1980s (exact date unknown) T18/19 is taken out of use. Introduction of T23 (16A single phase) and T25 (16A 3-phase) plugs and sockets made single phase 380V T18/19 superfluous. For replacement 3-pin T18 plugs were still available in 2016.

Swiss T5a socket Schemes of Swiss T5, T5a and T5b sockets
Swiss T5a plug

Three-phase 10A - 380V T5a type socket (no.13) and plug (no. 14). Three variants have existed: T5, T5a and T5b, see schemes above. T5 plugs have pins for R (T1), S (T2) and T (T3), but no neutral pin. Because sockets have an earth pin it is likely that the design dates back to the 1930s. T5 series are taken out of use in the 1980s in favour of T15.
Manufacturer of plug: Feller AG in Horgen.

Shown T5a plug and socket are not part of the museum collection. I am grateful to Ward Haalebos for providing photos.
Please contact the museum if you can help me with T5 material. Find museum mail address at the start page).


Swiss T7 15A-500V 3-pin "cooker" socket
Swiss T7 15A-500V  3-pin "cooker" plug
Swiss T8 15A-500V 4-pin "cooker" socket
Swiss T9-like 15A-500V 5-pin "cooker" socket

Classic Swiss porcelain cooker socket
Swiss 25A-500V 4-pin "cooker" plug. made by JJB
Swiss 25A-500V 4-pin "cooker" plug, made by Resista

Images 15 - 21 show "Kochherd" (cooker) sockets and plugs. They are gradually replaced by IEC 60309 types and therefore no longer for sale.

15,16 T7, 2-phase +E, 15A- 500V socket and plug. The line contacts are connected to either L1 and L2, or L1-L3, or L2-L3. Each combination offers 400V (previously 380V). Pin dimensions are: 24.7 / 6.0 mm for earth pin, and 21.7 / 5.0 mm for line pins.
Manufacturer of socket and plug: Feller AG in Horgen (ZH).   {AR}
17 T8, 4-slot 15A-500V socket. According to Swiss standards T8 specifications are: T1, T2, T3 and protective earth.
The contacts of shown socket still had its original wiring with red, green, yellow and yellow/red cords. These colors were used for respectively R (L1), S (L2), N and earth, which point to a 2-phase + neutral and earth connection.
Slot dimensions: 6.0 mm (bottom right) and 5.0 mm (bottom left and top right, left). Socket has an ASEV lmark.
Manufacturer: Adolf Feller AG in Horgen.   {PdV}
18 3-phase +N+E, 15A - 500V socket. Configuration of contacts is similar to 25A T9 sockets (not in collection). Slot dimensions: 5.0 mm (L and N); 6.0 (earth). Manufacturer: XAMAX AG in Zürich.   {AR}
19 Unknown porcelain cooker plug. Inner diameters; central, elevated slot: 8.0 mm (probably for earth pin), slot with red ring (top tight): 6.0 mm, both remaining slots: 8.0 mm. The "out of use" slot is empty. Distance between two "horizontal" and two "vertical" slots is 28 mm, a size that is nearly identical to T8 and T9 sockets and T10 pins (see plug no. 20).
It seems likely that the porcelain socket is a very early cooker socket model (1910s-'20s ?). Unfortunate, information about rating and manufacturer lacks. No ASEV mark.   {PdV}
20, 21 T10, three-phase plugs with earth pin rated at 25A - 500V. Resista plug no.21 has a robust, rubber housing. The three power pins (L1, L2, L3, are not specified) have a length of 27.0 mm and diameter of 7.5 mm. The protective earth pin is 29.5 mm long and 10 mm thick.
Manufacturers are: no. 20: plug has a JJB logo, which means that it has been made by the TH-contact branch of Tschudin & Heid in Rheinach (BL), formerly Jean Jaques Buser,  {WN};   no. 21: Resista Electric in Renens (VD), Switzerland  {FSE}

Swiss 15A-500V 5-pole inlet

Swiss T34 wall socket
Swiss 15A-500V 5-pole plug

Swiss T34 wall socket

Swiss T52 25A-500V  4-pole industrial inlet

22, 23 J15-5 inlet (no. 22) and plug (no.23). The Swiss J-series was designed for 500V 3-phase industrial and agricultural purposes. Improved mechanical resistant strength is an important feature of the J-series compared to domestic plugs and sockets.
Types with and without neutral contact have existed for 15A, 25A, 40A and 75A.  J15-5 is 5-pin (L1, L2, L3 +N and protective earth) 15A type. The corresponding SEV code is T34.
Sales of J-types ended July 2008 in favour of IEC 60309 plugs and sockets. J15-5 was replaced by IEC60309 (6h) 16A-400V, 5-pin (see images 4 and 5 on IEC 60309 page). The IEC model has SEV code T75.
Manufacturer: Adolf Feller AG in Horgen.   {PdV}
24a, b
J15-5 / T34 wall socket. Image 24b shows the rear side. Neutral wire connector is indicated with a yellow label (see cord colors). Protective Earth contact has a yellow with green line label.
Socket has three marks: left: manufacturer logo (AFH = Adolf Feller, Horgen); middle: Swiss certification mark ASEV, used until 2002; right: droplet, indicating splash water resistance (socket was in an outside wall).   {EvdW}

25 Cast iron T52 inlet, rated at 25A - 500V. The rightmost slot is the protective earth connection. To show its long working life the decision was made not to clean the object.
The heavy duty series comprised of 25A, 40A and 75A models, with and without neutral contact.
No indication of manufacturer.   {PdV} 


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