Electrical engineering - Basics Page 43
Further cable characteristics are often printed on the cables themselves informing
about e.g. nominal voltage, insulating and sheathing material, conductor type,
wire type, etc...
All electric devices, cables and plug and socket connections have to cope with
the VDE regulations and have to carry the VDE sign (see table under point "4.
Symbols of electric components").
The CEE-norm which has been introduced in 1981 has the following advantages
for three-phase current plug and socket connections:
The objective of the CEE-norm
that it should not be possible to confuse plugs anymore is achieved with a special
positioning of the earthing contact socket. Furthermore, the plugs have different
colours and the earthing contact socket PE additionally has a larger diameter
than the sockets for the poles of the outer conductors L1, L2 and L3 and the neutral
- stronger currents can
- splash water-protected
and waterproof models can be produced easier
- plugs are made only
for a specific voltage connection box and do not fit into higher voltage connection