Abstract
Thermal issues shorten motor life. Modern motor relays must protect for these effects, which can occur for motors from small to large (50 hp and greater) and for all voltage operational levels. However, being too conservative on thermal limits decreases motor productivity. An ANSI/IEEE 49 thermal element creates a realistic thermal model of the motor because the element takes the load level and negative-sequence currents into account. The 49 thermal element is superior to older methods using inverse-time overcurrent elements (51). This paper discusses updates in the existing 49 thermal model implementation. Also discussed are resistance temperature detector (RTD) biasing, RTD voting, and the role of transducers in the modern motor relay.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.