In the case of electrical commands, in the multi-wire schemes, the representation of all the elements and connections are properly represented and the components are indicated according to their installation sequence, always considering their physical construction. The position of the contacts is carried out with the system switched off. The layout of the elements of the circuit can be any shape em3714t, relying on the advantage that they are easily recognizable. Interlocking with buttons can also be carried out by means of pushbuttons. It is extremely important that in order to understand the entire graphical representation of an electrical circuit, one knows the basic components and devices that are part of the electric commands, as well as their purposes.

Thus, the interlocking process is related to the mechanism of connection between the auxiliary contacts of various devices, by which, the operating positions of these devices become dependent on each other. Through this process it is possible to avoid connecting certain devices before others allow this connection. The seal is always connected in parallel with the closing contact of the button. Its main function is to keep current flowing through the contactor even after the operator has removed the finger from the button.