US Patent 7835141 Electric power distribution system

There is a concern that water on the top surface of a cover 50A will penetrate the top face of a case 20 through gaps between an opening portion 51H and parts accommodation portions 34 because the parts accommodation portions 34 are exposed to the outside at the opening portion 51H on the top face of the cover 50A while the electrical connection box P is positioned in the cover 50A. Because drainage grooves 35 and 36, which reach the drainage channels 38 on the outside face of the case 20, are formed on the top face of the case 20, water that remains on the top face of the case 20 (the main body portion 30) is reliably drained by flowing into the drainage grooves 35 and 36.