Well to calculate the capacitor bank size,u must determine ur current power factor and decide on the new power factor to be achieved depending on ur country's regulations but normally its between 0.95 and 1
Judging from the equipment u have,ur power factor is at 0.8-0.9,but better to determine them from the nameplate
to get the kvar for example:
tan(arccos1)-tan(arccos.8)=Y
then KVAR=Y x KW ( and not KVA)