As part of an emergency work project, FEL carried out the retrofit of four 1600A, 600 V Masterpact breakers supplied from stock and ready to install. The arc flash study was not compliant with current requirements on the older Federal breakers, so the building was out of service and operating on diesel generators only to maintain essential equipment. The client was satisfied with the speed and quality of the work, and in less than 48 hours the retrofit was completed and certification was issued so the facility could return to service.