SM Start Sequence Control

The 869 Start Sequence Control function provides:

• Controlled application of a DC field to the rotor winding for both brush

type and brushless synchronous motors.

The start sequence function is comprised of three field application

control methodologies:

– Slip-frequency based for brush-type motor applications.

– Timer-based for both brushless and brush-type motor applications.

– Reluctance-torque based synchronization for brush-type motor applications.

• Incomplete start sequence protection to trip/alarm if the starting

sequence is not completed within a set time.

• Load application relay functionality enabling motor loading following

the DC field application and unloading following a trip and/or loss of

synchronization (pole slipping).

• Start sequence control when the motor enters re-synchronization mode.