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[8023-POEP] List of questions regarding cabling and connectors

Hi guys,

 

Please see below list of questions that I have composed.

Please feel free to add additional questions and comments so Mike can send the letter as per our action item.

 

Thanks

 

Yair

-----------------------------------------

 

  1. Connectors that are used with an 802.3af components (PD and or PSE) should be tested with a compliant PD load and not with general purpose load as we seen in John presentation.

      The load presented is not relevant to the PoE components due to the presence of Diode Bridge in the PD, minimum capacitance of 5uF and much lower inductance.

 

  1. The voltage used in PoE technology is 60V max and not 72V. Please consider relevancy to connectors used in PoE systems.

 

      3.    IEEE802.3af allows 350mA continuous current on 2 pairs which is 175mA per conductor. ISO liaison letter permits 197mA per conductor for all conductors.

             -What is the expected temperature rise in typical cabling installation?

             -What is the expected temperature rise in worst case installation?

             -What is a worst case installation? Is there definition of such installation?

 

3.1        What will be the temperature rise for the following current ratings per conductor: 175Ma, 200ma,210mA, 240mA, 300mA, 350mA under the following operating conditions:

3.2        A cable with 8 wires, all wires conducting.

3.3        A cable with 4 wires, all wires conducting.

3.4        A cable with 8 wires, 4 wires are conducting.

3.5        All the above cases 3.2 to 3.4 under worst case installation (bundled cables, how many cables per bundle)

 

  1. What is the recommended testing model?

 

  1. How the 802.3af current levels can work with cables rated to 60 deg C.

 

4.1    In our opinion there is no safety issue with the above current levels since the UL permits 1.3A per conductor at the rated temperature and our current levels are much lower then this value. But is the ISO opinion about this statement.