Unexpected changes to the protection of a 4160 V motor

Careful consideration must be made when determining the proper specifications, application, starting method, and protection of a medium voltage motor-load combination. These considerations should include the type of load, the load duty cycle, the design of the overall facility electrical power system and information regarding the utility power system. This paper discusses a case at a newly constructed Midwestern industrial plant whereby these stated considerations were not properly followed which in turn lead to plant start-up electrical system design and protection changes in order to keep the plant startup on schedule.