Consideration must be given to the volt drops of the motor circuit. The motor circuit is from the point of the motor circuit’s connection to the site’s electricity distribution network to the motor terminals. As a general rule the maximum volt drop between the motor circuit’s point of connection to the site’s electricity distribution network and the motor terminals should not exceed 2.5% at the motor’s full load current or 10% at the motor’s starting current.
Where the supply to the motor is derived from a motor control centre (MCC) the volt drop at the busbars of the MCC containing the starter should not exceed 3% at the motor’s starting current.
Where a motor has an individual starter connected to a distribution switchboard or where the MCC derives it’s electrical supply from a distribution switchboard the volt drop at the distribution switchboard busbars should not exceed 1% at the motor’s starting current.
For the purposes of volt drop limitations groups of motors that start simultaneously should be considered as one motor.