Here is the universal rule for sizing the wire for a capacitor of any size and voltage. Wire shall be sized at 135% of the rated current of the capacitor. For a 240kvar, 480V capacitor Nominal current is 288A = 288A x 1.35 = 389A Looking at the wire size chart from UL508A or the NEC we need a single 600MCM copper wire good for 420A OR 2 x 3/0 AWG good for 200A each3/0 is kind of oddball so the customer might use 2 x 4/0 AWG The lugs inside the fixed bank unit accept 2 x #4-500MCM