Asus AP1720-E2 - Manual (Page 76)

Chapter 2: Hardware setup 2-56
2. Use a power supply module
handle to push the power supply
until it fits in place.
3. Secure the power supply to the
chassis with two screws on the
metal brackets on each side.
The standard server system comes with two power supply modules
with no redundant power function. To achieve redundant power supply
function, you must install an optional third power supply module.