CWT Power over Ethernet (PoE) & Cabling Infrastructure 2

Question 1

What is the maximum PSE power output per port defined by IEEE 802.3bt Type 4 (Class 8)?

Accepted Answer

90 watts

Answer

IEEE 802.3bt Type 4 delivers up to 90W at the PSE using all four wire pairs, enabling high-power devices like multi-radio access points and PTZ cameras.

Question 2

In IEEE 802.3af/at Alternative A power delivery mode, which wire pairs carry the power signal?

Accepted Answer

The data-carrying pairs (pins 1, 2, 3, 6)

Answer

Alternative A delivers power on the same pairs used for data transmission by superimposing a DC offset, while Alternative B uses the spare pairs.

Question 3

What is the function of PoE PD power classification?

Accepted Answer

To allow a PD to signal its maximum power requirement to the PSE

Answer

PoE classification allows a PD to communicate its power class (0–8) to the PSE so the switch can allocate the correct wattage and manage its total power budget efficiently.

Question 4

A wireless access point is PoE Class 3 under IEEE 802.3af. What is its maximum allowable power draw at the device?

Accepted Answer

12.95 watts

Answer

Under IEEE 802.3af, a Class 3 PD can draw a maximum of 12.95W at the device after cable losses, making it the highest class under the original PoE standard.

Question 5

What is the primary purpose of a PoE splitter?

Accepted Answer

To separate power from data so non-PoE devices can use PoE infrastructure

Answer

A PoE splitter separates the DC power from the data signal on an Ethernet cable, providing a standard data port and a separate DC power connector for non-PoE-capable devices.

(CWT) Certified Wireless Technician Practice Test

(CWT) Certified Wireless Technician Practice Test

CWT Power over Ethernet (PoE) & Cabling Infrastructure 2