Numbering of contactors and relays in wiring diagrams
Numbering of contactors and relays in wiring diagrams
(OP)
Hi,
I have some questions regarding how contactors and relays are numbered (tagged, identified) in wiring diagrams. I’m new with wiring diagrams and I see most of the times contactors are numbered K1, K2 or K3 and relays are numbered from K9, K10, K11 and so on.
Is there a rule how these components should be numbered? Is there a sequence for contactors, let’s say from K1 to K8, and relays follow from K9 onwards?
Thank you!
I have some questions regarding how contactors and relays are numbered (tagged, identified) in wiring diagrams. I’m new with wiring diagrams and I see most of the times contactors are numbered K1, K2 or K3 and relays are numbered from K9, K10, K11 and so on.
Is there a rule how these components should be numbered? Is there a sequence for contactors, let’s say from K1 to K8, and relays follow from K9 onwards?
Thank you!





RE: Numbering of contactors and relays in wiring diagrams
Relays perform control functions. Relays are K1, 2, 3.
Contactors switch power to end devices such as motors or lighting. Contactors get C1,2,3.
old field guy
RE: Numbering of contactors and relays in wiring diagrams
xnuke
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RE: Numbering of contactors and relays in wiring diagrams
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Numbering of contactors and relays in wiring diagrams
RE: Numbering of contactors and relays in wiring diagrams
Thank you all for your input... I'm from Europe so the IEC standards apply and we are using "K" numbering for contactors and relays. Jraef, do you know which IEC standard is for the numbering of these components?
RE: Numbering of contactors and relays in wiring diagrams
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Numbering of contactors and relays in wiring diagrams
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
RE: Numbering of contactors and relays in wiring diagrams
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington