Hi guys,
Coming back to subject... I did some research for the last few days but unfortunately I couldn't find anything concrete. I checked IEC 60947, IEC 61082, IEC 61346 but without success. The only thing I could find are some remarks in the EATON Wiring Manual, beginning of chapter 10 where is stated :
Marking to DIN EN 81346-2 (IEC 81346-2)
.......
Eaton uses the above standard.
In addition to that, Eaton specific decisions have been made with regard to the interpretation of the standard that sometimes deviate from the standard.
• The marking of connection terminals are not readable from the right.
• A second code letter for the marking of the use of the equipment is not given, e.g.: timing relay K1T becomes K1.
• Circuit-breakers with the main function of protection are still marked with Q. They are numbered from 1 to 10 from the top left.
• Contactors are newly marked with Q and numbered from 11 to nn. e.g.: K91M becomes Q21.
• Contactor relays remain K and are numbered from 1 to n.
Also I found in IEC 61346 (Table 1) that objects are grouped in classes according to their purpose or task and each group has a letter code associated... for example:
Code - F
Purpose or task of object - Direct protection (self-acting) of a flow of energy, signals, personnel or equipment from dangerous or unwanted conditions
Examples of typical electrical products - Fuse, Miniature circuit-breaker, Thermal overload release
Code - K
Purpose or task of object - Processing (receiving, treating and providing) signals or information (excluding objects for protective purposes, see class F)
Examples of typical electrical products - All-or-nothing relay, Contactor relay, Delay element, Synchronizing device, Time relay, Transistor
Code - Q
Purpose or task of object - Controlled switching or varying a flow of energy, of signals or of material. (For signals in control circuits, see classes K and S)
Examples of typical electrical products – Circuit-breaker, Contactor (for power), Disconnector, Fuse switch, Fuse-switch-disconnector, Motor starter, Power transistor, Slip-ring short-circuiter, Switch (for power), Thyristor... (If main purpose is protection, see class F)
Code - S
Purpose or task of object - Converting a manual operation into a signal for further processing
Examples of typical electrical products – Control switch, Discrepancy switch, Keyboard, Push-button switch, Selector switch