LVR Controller Operation:

1. Place the START switch in Run that energizes coil M, closing the M contacts and beginning the motor.

2. Whenever a low voltage condition occurs then the M coil drops out, opening the M contacts and de-energizing the motor. While normal voltage is restored, the M coil is again energized and closing the M contacts and restarting the motor.

The LVRE controller manages the motor across the line at all times. This category of controller is of the manual variety and is found mostly on small loads which must begin automatically upon restoration of voltage which is display in the figure. An LVRE controller might or might not hold overloads. They will be placed in the lines to the load if overloads are used.

The motor controllers which have been described are extremely basic. There are several automatic control functions which could be incorporated into these categories of controllers, but they are beyond the scope of the given text.

Figure: LVRE Controller