Classic heavy duty plugs and sockets
|Sockets and plugs shown below were used in
Poland in the second half of the 20st century, but are replaced
gradually in favor of IEC 60309 devices.
Each of the plugs and sockets has been collected for the museum by Wojciech Maciak.
Found on nos.
1 (socket), 2 (25A),
3 (socket + plug),
found on nos.
1 (plug), 4 (socket),
Logo with A-4 mark,
found on socket
nos. 6 and 8.
See also A-4 mark on
63A socket (image no. 14).
polarized single phase socket and plug, rated at 16A - 380V. Flat blade
pin sizes: width 8 mm; 2.9 mm thick; length: 22.3 mm (power
pins), 25.2 mm (earth pin). Manufacturer of socket: Ospel S.A., a
company founded in the 1950s and still producing plugs, socket,
switches etc. Matching plug has no Ospel logo, but an A-19 mark (see
image on second row, right). See note on A-marks at bottom
|2||25A - 380V plug,
comparable to the 16A version (no.1). Flat blade pin
sizes: width 9 mm; 3.4 mm thick; length: 25 mm (power pins), 28.3
mm (earth pin). Manufacturer: Ospel S.A.
three-phase, 4-pin socket and plug, rated at 25A - 380V. Flat blade pin
sizes: power pins 9 x 3.3 x 25.8
mm; earth pin: 9 x 3.4 x 29 mm. Specification of power pins (R, S, T /
L1, L2, L3) is not indicated. Manufacturer: Ospel S.A.
||Bakelite, round pin single phase socket and plug, rated at
25A - 380V. Pin length: 24 mm; diameter: 7 mm (power pins) and 5 mm
(earth pin). Manufacturer of plug: Ospel S.A.; socket has an A-19 mark.
round pin three-phase, 4-pin socket and plug, rated at 25A - 380V. Pin
length: 24 mm; pin diameter: 7 mm. The plug is polarized because of the
off-center position of the earth pin. Moreover, the spacing between the
top two power pins is 4.8 mm larger than the spacing between top and
bottom pin. Power pins are not specified. Manufacturer of socket has a
logo with A 4 that also has been found on 25A socket no. 8. Plug has an
A-19 mark. See note on A-marks at bottom of page.
|Images of sockets and plugs nos. 8 - 13 are
shown in proportion. Each has a zinc alloy die cast housing.
- 380V, 3-pin, three-phase socket. A clip (see inset) serves as
protective earth connection between plug and socket. The unknown logo
has also been found on the 25A - 380V Bakelite socket no. 6.
- 500V single phase socket. The earth contact (see image no. 15) is
connected to a screw, indicated by an earth symbol, on the outside of
cast. This feature applies also to socket nos. 11 and 13. The socket
has a 'cn' (?) mark that has also been found on several other die cast
16A - 500V plug with cap. The corresponding socket is not in the
collection. Socket contacts resemble those of socket no. 11 (see image
no. 15 for difference in size).
||32A - 500V
three-phase socket and plug. Both have an IP44 protection against
ingress of dust and splash water.
- 500V three-phase socket. Socket is polarized because of a
subtle difference in offset of the earth pin, indicated by a red arrow
in image no. 15. Ingress protection according to IP44 protocol.
given on the cast of 32A socket no. 11 (left) and a 63A socket
identical to no.
13. The significance of the mark showing a
circle with cn (or ch?) inside is still a mystery.
Please contact me if you recognize these Polish marks (museum address
given at the home page). Details about the
other marks are given below.
of slot configurations of 16A, 32A and 63A - 500V sockets. 32A and 63A
material has a Polish Center
for Testing and Certification
(Polski Centrum Badan I Certyfikacji) mark. Red arrow points to the
larger offset of the earth slot, compared to R, S and T slots.
According to a 2016 catalog this
material is still available, probably only for replacement of old
devices that are still in use. For new installations IEC 60309 material
has to be used.
* slot configuration is deduced from 16A plug no. 10.
on plugs and sockets made in Poland from 1950s until end of 1980s.
The Polam mark has been used by the Polish Union of state-owned producers of light sources and armatures. Some manufacturers produced also switches, plugs and sockets. Polam unification was effective from December 31, 1971 until 1989. The name Polam was derived from the leading Polam light bulb factory in Pabianice. See source for additional information (in polish language).
The company specific marks have a letter indicating the type of industry, followed by a number that specifies the manufacturer.
'A' indicated producers of fuse boxes, switches, plugs, sockets and similar small electrical accessories. 'M' referred to manufacturers of motor and transformers; 'T' to radio and telecommunication.
A, M and T marks have been introduced in the 1950s, mainly for hiding the company name and its location.
4 = Electrical equipment factory in Bydgoszcz, founded in 1923 by Stefan Ciszewski.
In 1957 renamed to Eltra. Now Elda-Eltra S.A, part of Schneider Electrics.
19 = Polam-OSPEL in Wierbka, now OSPEL S.A.
The museum is grateful to Jarosław Dubowski for providing information about Polam and A, M, T marks.
|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|