ABSTRACT
The design and construction of a 60A, 3-Ф automatic power changeover from public utility supply to generator and vice versa was aimed at providing a useful system for use in our homes or offices. The system was achieved with a 66A 3-Ф contactor, 100mA transformers and relays. The system turns on a generator when the public utility (PHCN) is off by cranking the starter and a provision was made to stop cranking when the generator is fully started. A delay was provided to stop the generator five minutes after the PHCN is restored to avoid unnecessary off and on.
A display that shows when PHCN or GEN is on was provided.