Enhanced PoE port power available from switch?

rmalleck0508 · ‎08-24-2010

Can a WS-C3560E-24PD-S switch with a C3K-PWR-750WAC power supply, provide enough power to supply enhanced PoE of 20 watts (Power draw of access point per data sheet of model 1252 Wireless access Point with 2 radios) for all 24 ports simultaneously?

If not, how does it work? 4 ports get nothing? All ports get less power? Circuit breaker pops?

I'd appreciate it if any answer gets supported by showing calcs and/or pointing to spec sheets - as I need this information for our engineering design basis.

Thanks in advance...

paolo bevilacqua · ‎08-24-2010

20 x 24 = 480W.

PS is 750W.

Data sheet says:

• Enhanced PoE supporting up to 20W of PoE per port

• Industry first portfolio to scale beyond 15.4W per port delivering maximum solution simplicity for 802.11n access point deployments

It will work no problems

rmalleck0508 · ‎08-25-2010

Thanks for the replies!

From the switch spec sheet in table 5 "Power Specifications" under the conditions: "100% Throughput (With Maximum Possible PoE Loads)", the measured power consumption for the switch itself is: 502 watts

Under this condition: Switch itself + 24 ports of EPoE power sourcing

502 watts + (24 * 20 watts)

502 watts + 480 watts = 982 watts

982 watts > 750 watt rating of the power supply

So what happens under these conditions?

Even for this load condition for normal PoE (15.5 watts per port) from the spec sheet Table 5 "Power Specifications" again:

Measured Power Consumption is: "502 Switch and 372 PoE Power"

372 = 15.5 * 24

So even under this condition, power consumption is (502+372) = 874 watts, which appears to be above the 750 watts available.

Leo Laohoo · ‎08-24-2010

WS-C3560E-24PD-S switch with a C3K-PWR-750WAC

That should be no problem. Upgrade your IOS to 12.2(46) to enable enhanced PoE.