Motor Starter Circuit Diagram

That is the terminal marking stated on respective component as per the standard.....NEMA, IEC etc.

Thank you very much for your prompt response.

I have one more question: is there a NEMA or IEC standard on these component markings or are the markings from the manufacturer of the relevant component,

Number are used to id terminations, terminals, wires (both ends of) and components in an electrical circuit.

If you study your electrical drawing you will see, for example, a NO contact on a relay or contactor has the numbers "13 & 14". In many cases the wire coming off terminal "14" might be numbered "14", that is, the builder of the panel has continued the numbering system onto the wire so you can trace that wire to its next connection.

Imagine if you can, looking at a electrical panel with all RED wires running all over the place and you have a fault! You will have to trace EACH wire, however if they have number or even letters or a mixture of both... then its as easy as reading the diagram!

Thank you for your time.

I have one more question please: is there a standrd procedure for such numbering or is it left to the designer to randomly number the contacts and wires? From the other response from Mr Abele, it appears that the numbers correspond to those marked by the manufacturer of the components e.g on the thermal overload relay or on the level relay.

The numbers you are referring to here are all from an IEC standard. It is a very strict system, the positions of the evices even dictate the numbering. So for example if you see a set of contacts that are numbered 13, 14, that not only tells you they are NO, it also tells you they are on the left side of the device they are attached to. I'm going strictly by my damaged brain cells, but I want to say this is IEC standard 60531. I'm probably wrong though. If you look in the technical section of any large IEC component mfr catalog like Siemens, there will be an explanation of this and citation of the IEC standard that applies to it.

On all of the relays I have used in the past 13 and 14 are coil terminations.

I have commonly seen, at least in Europe, A1 and A2 used for coil terminations.

Thanks, your explanation is clear and precise. I have a further question. To my understanding, NO or NC condition is when a motor or any circuit is not running or not in operation. Please let me know if I am right.

You are correct, when the component is at rest, (Non energized) it is considered N.O. / N.C. positions. In the case of the Overload, in the Non tripped condition N.O / N.C. is the same as above.

It's IEC 60947.

Had a 60 in it anyway...