IEEE 802.3at (PoE+) provides up to 30 watts of power per port. To determine how many devices can be supported with a total budget of 740 W:
740 W ÷ 30 W per device = 24.67
However, due to real-world power overheads and cable losses, it's safe to estimate each device may draw up to ~25–30 W. Most vendors recommend a planning budget of around 25–28 W per 802.3at device.
Safe calculation using full 30 W:
740 ÷ 30 = 24.6 → you could theoretically power 24, but for guaranteed power availability considering margin, most designs plan for:
740 ÷ 40 = 18.5 → about 18 devices conservatively
Answer: 18 devices can certainly be powered.
— Reference: CWDP-305 Official Study and Reference Guide, Chapter on Infrastructure Design
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