Generator Alternator

the alternator output is checked to ensure that it is within specification. If so, then the generator contactor is energised and the load is supplied from the generator. When the mains supply returns, the mains available lamp is illuminated within specified limits. The main is then monitored for a pre-set time to ensure that the supply is stable. The generator contactor is then de-energised and the mains contactor energised so that the mains supply is restored to the load. The 'alternator available' and 'alternator on-load' lamps extinguish and 'mains on load' lamp is illuminated. A short break in approximately 1 second occurs whilst the changeover is complete.