Part 3: as measured in BTUs. So, since these units do not measure the same thing, they cannot be converted into each other. However, looking at the energy from the BTU given off by the AWG of the wire and the amps passing though, we are only looking at an approx raise of 10F for a bundle of 100 cables.
Part 2: s defined in IEEE 802.3AT. Of course in physics, temperature and heat are not the same thing (although they are synonymous in normal English usage). To explain, the heat content of an object depends upon both the temperature and the heat capacity of that object, so for example, one liter of water has only half the heat capacity of two liters of water; even if yo liter container is at exactly the same temperature as the two liter container, it still has only half the heat content of -
Hey Violetdav, I asked Jimmy Ray what he thought and he's what he said: I certainly understand and can tell you that I initially felt the same way. However, after reading ISO/IEC and TIA/TR-42 that certified this I was a little more relieved. But an engineer should always want to see the math right? If we take 51W of power the standard allows for 600mA. Since we know the watts we can take 51w*3.413 and get 174 BTUs. Now remember the max amps (Amps is the heat baby!) on Cat5E is 720mA -
this is so cool!
MakoXL 22 hours ago
Part 3: as measured in BTUs. So, since these units do not measure the same thing, they cannot be converted into each other. However, looking at the energy from the BTU given off by the AWG of the wire and the amps passing though, we are only looking at an approx raise of 10F for a bundle of 100 cables.
ciscoCIN 4 months ago
Part 2: s defined in IEEE 802.3AT. Of course in physics, temperature and heat are not the same thing (although they are synonymous in normal English usage). To explain, the heat content of an object depends upon both the temperature and the heat capacity of that object, so for example, one liter of water has only half the heat capacity of two liters of water; even if yo liter container is at exactly the same temperature as the two liter container, it still has only half the heat content of -
ciscoCIN 4 months ago
Hey Violetdav, I asked Jimmy Ray what he thought and he's what he said: I certainly understand and can tell you that I initially felt the same way. However, after reading ISO/IEC and TIA/TR-42 that certified this I was a little more relieved. But an engineer should always want to see the math right? If we take 51W of power the standard allows for 600mA. Since we know the watts we can take 51w*3.413 and get 174 BTUs. Now remember the max amps (Amps is the heat baby!) on Cat5E is 720mA -
ciscoCIN 4 months ago
I still say this cannot (should not) be done over Cat5 or 5e cabling but a Category 6 or better yet 6A and above.
1) The heat build up in C5 cable from PoE or PoE+ is already a degrading factor in network performance.
2) When deploying this for VDI and other bandwidth hungry applications higher rating cabling is already standard.
I understand that they don't want to alienate legacy networks, but Cisco needs to address the Layer 1 (Physical) needs when touting this.
violetdav 4 months ago
Love this show!
robboyd 5 months ago