As a general rule, the total maximum power consumption of all connected access points should not exceed 80% of the switches total power capacity.

As an example, the UAP-AC-PRO has a maximum power consumption of 9 watts. If 24 UAP-AC-PRO's were connected to a US-24-250W, the total potential power consumption of all the access points would by 24 x 9 = 216 watts. Since 80% of 250 watts = 200 watts, this would exceed the recommended maximum POE output of the switch. In this case, it is recommended to upgrade to the US-24-500W.