An external automatic disconnect device should be used to prevent voltage back-feeding into the static bypass.
Disclaimer: This article is for informational purposes. Always refer to the official manufacturer’s documentation for your specific UPS model and serial number before performing any electrical work. High-voltage equipment should only be serviced by qualified personnel. liebert hipulse d ups manual
If you are referencing the manual for a specific task, pay close attention to the and DANGER labels regarding the DC Bus . An external automatic disconnect device should be used