What is the primary reason for placing heavier devices toward the bottom of the rack...

Theprimary reasonfor placing heavier equipment, such as UPS units or core switches, at thebottom of a rackis tomaintain stability. A lower center of gravity reduces the risk of tipping, especially when the rack is not yet bolted or braced.

This is a standard safety precaution in network hardware installation and is particularly important when racks are being serviced or relocated.