EN 50005:1976

1 Scope
2 General
3 Terminal marking of impedances (alphanumerical)
4 Terminal marking of contact elements for switching
  devices with two positions (numerical)
5 Terminal marking of overload protection devices
6 Distinctive number

This standard applies to switchgear and controlgear for industrial use having rated voltages not exceeding 1000 V a.c. and 1.200 V d.c. It is based on the uniform system of terminal marking specified in IEC-Publication 445-1973. The use of this system is recommended for the terminal marking of devices which are frequently contained in low voltage switchgear and controlgear assemblies, when such marking is a requirement of the relevant equipment standard or is usual practice. Where an identifying colour, in accordance with a recognized system, is applied to an apparatus terminal, the correlation between this colour and the equivalent graphical symbol or the alphanumerical notation according to this standard shall, where necessary, be recorded on an associated drawing or document. This standard forms the general rules. Additional European standards will give the rules for particular types of devices such as contactor relays, contactor auxiliary contacts, control switches, etc. The terminal marking applies to devices as delivered by the manufacturer