[PDF] Wiring Diagram Book - daltco FIG. 3 FIG. 4. Auxiliary contacts on contactors, relays and push button contacts use 2-digit terminal designations, as shown in the diagram above. The ﬁrst digit indicates the location of the contact on the device. The second digit indicates the status of the contacts, N.O. or N.C. “1” and “2” indicate N.C. contacts. Contactor Wiring Diagram Pdf | Free Wiring Diagram Collection of contactor wiring diagram pdf. A wiring diagram is a streamlined traditional photographic representation of an electrical circuit. It shows the parts of the circuit as simplified forms, and the power and signal links between the tools.