Automatic Sequential Motor Control Circuit Power & Control

Wiring diagrams Wiring diagrams show the connections to the controller. Wiring diagrams, sometimes called " main " or " construction " diagrams, show the actual connection points for the wires to the components and terminals of the controller.. The diagram also shows numbering for the wires in the device. This is essential for industrial control systems that may contain hundreds or thousands of wires. These numbering schemes are often particular to each facility, but there are tools to help make wire labels that will appear in the final controls cabinet.

Motor control relays can be energized from the same supply as the motor or from lower voltage sources that are interlocked with the main power supply. The interlock de-energizes all power to the motor and control for safety The symbols above are combined into diagrams called ladder diagrams.. Motor contactor (or "starter") coils are typically designated by the letter "M" in ladder logic diagrams. Continuous motor operation with a momentary "start" switch is possible if a normally-open "seal-in" contact from the contactor is connected in parallel with the start switch so that once the contactor is energized it maintains power to itself and keeps itself "latched.