US Patent 7538540 Bus bar current detecting apparatus

A current detecting portion A includes a magnetic shield attached to a bus bar BU, a magnetic shield attached to a bus bar BV, and a magnetic shield attached to a bus bar BW. On bus bars BV, BU and BW arranged in parallel, current sensors SU, SV and SW are arranged at alternately displaced positions along each bus bar. The magnetic shields are also arranged at alternately displaced positions along each bus bar. The arrangement of the magnetic shield and the current sensors is what is called a staggered arrangement, whereby magnetic interference from an adjacent bus bar to a current sensor can be avoided.