Solar Energy (Photovolatics)
Hidenori Araki
Business Development Manager
Nord-Lock Group
It is common practice to torque check at least yearly on critical bolted connections for PV systems out in the field. However, how often do you come across a loosened bolt/nut prior to that maintenance cycle and potentially causing downtime and production loss? Why do these connection loosen over time even though one may have torqued properly and to specification? We will discuss the risks and challenges of vibration-induced bolt loosening that could occur in high wind environments and why conventional bolt locking methods fail. As part of this discussion the Junker vibration test method (DIN 65151) will be introduced as a way to evaluate bolted joint behavior in transverse motion that could be observed in critical PV connections. Attendees will learn what the Junker vibration test entails, its design parameters, and how it could be used to evaluate suitable bolt locking systems in high wind areas where bolt loosening on critical PV connections are more susceptible. Attendees will have a chance to get to see the test up close and personal and run the test as well. This is an extension from “Vibration-Induced Bolt Self-Loosening Phenomenon in Solar Applications” session.