HP Parallel Uninterruptible Power System - Manual (Page 58)

ERM installation 58
4. Insert screws through the mounting rail into the cage nuts or clip nuts.
5. Tighten the wing nuts or hex nuts.
Preparing the rails for integrated shipping
If the unit is to be shipped in a rack:
1. Remove the hex nuts from the mounting rail.
2. Install the rail reinforcement plates and tighten using the hex nuts with captive washers, included in the
kit, instead of the nuts included with the rail.