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I have put together a schematic of a Hipot test fixture that can be used on the PSE port.
This is just one example of how isolation to frame ground can be tested, and
further simplifications could be made.
There is a manual DPDT switch shown for each set of wire pairs (1236 and 4578) that can be positioned
for whether that pair set is powered or not powered.
When the pair set is powered, the circuit shown provides the signature resistor, and the 48V load to allow
the 48V to remain on during the test.
Each PSE can be Hipot tested for the following operating modes.
PSE that is powered off
PSE running the discovery process
PSE providing DTE power
In each case, the PSE operating mode should be established before energizing the Hipot tester
Any PSE port should be able to pass the Hipot test under these conditions, based on the existing
802.3 spec that contains isolation requirements without regard to system operating mode.
Please send your comments to the reflector.