The auxiliary contacts of a contactor must strictly follow a specific category of numbering, taking into account that the number is properly formed by two digits, the first digit indicates the contact number and the second digit indicates if the contact is from normally closed type, one and two, or normally open, three and four. If the auxiliary contacts are numbered, they must follow a standard, and one and two are normally closed contacts, NF, with 1 being the input and 2 being baldor M1025T the output. And three and four are the normally open contacts, NA, with 3 being the input and 4 being the output.
In this way, in the relays and contactors have A1 and A2 for the coil terminals. The numbering of the contacts representing the force terminals is shown as follows, one, three and five are of the input circuit, line. The two, four and six are from the output circuit in the terminal. In the same way that each element present in an electric control circuit has its specific graphic symbol, the numbering of the contacts and the literal representation of them also has a standard that must be respected and followed.