To secure phase, voltage and ...

To secure phase, voltage and Ampere you can install these equipment at your panel:

RCP = Relay Control Phase, which has a purpose to secure electrical installation from phase loss, phase sequencing protection and in-balancies between phase

RCU = Relay Control Voltage, to secure any equipment at unstable Voltage

RCI = Relay Control Current, to secure equipment from any current variation

The common Relay which installed on the panel for Motor is only RCP.

Those all above relay protection will cut off power at control station.  No Sizing is neccesarry, because it is measure indirectly from the main power cable.