How are power distribution cables parallel-ed to split loads optimally? If the cables were exactly identical this would be easy but how is it achieved in general? e.g. Say there's a 11 kV to 420 V distribution transformer but the primary load is some distance away. Assume the load increases over time and the Ampere capacity of the original cable from TX to the load is full. As it often happens the transformer does have spare capacity so ideally only a second cable would be needed to transfer power. Are they simply paralleled between the two bus bars (TX and load) or is a more complicated scheme needed to be used for balancing?