In the following diagram a mechanical limit switch (LS1) has been placed in series with a Run/Stop contact and the “M” contactor coil. The Run/Stop contact is in the Run condition and the motor is running a process. This could be a conveyor or some other device. Note that the “M” contacts and the “Run/ Stop” are shown highlighted, indicating they are normally open contacts in the closed position. LS1 is a normally closed contact of the mechanical limit switch