Abstract: In an electrical power supply system provided with a step-down distribution transformer connected to a power source to supply current to at least one neutral grounded load center, said power source having a conductor connected to a first primary grounding connection, said distribution transformer having a magnetic core, and a primary and a secondary winding independently mounted on said magnetic core, said secondary winding being electrically connected to a pair of output terminals and to a center-tapped neutral terminal, said terminals being connected to said load center, said primary winding being electrically connected to a pair of input terminals arranged for connection to said primary power source, one of said input terminals being further connected to a second primary grounding connection, said center-tapped neutral terminal being connected to said second primary grounding connection via a shunting conductor, an improvement comprising a current balancing transformer (CBT) having a magnetic core and a fi