Re: [8023-POEP] isolation problem

[Steve Robbins <steven_robbins@xxxxxxxxxxxxx>]

Yair,

 

Yesterday I sent out an email stating that my analysis was wrong.  The sources are not connected to chassis, as several people pointed out.  Please disregard the diagram showing the gound loop.

 

Steve

 

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From: owner-stds-802-3-poep@xxxxxxxx [mailto:owner-stds-802-3-poep@xxxxxxxx] On Behalf Of Yair Darshan
Sent: Thursday, June 15, 2006 2:43 AM
To: STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-POEP] isolation problem

 

Hi all,

 

Something is wrong in this analysis.

The situation described here regarding current ground loops can't happen if you are 802.3 compliant.

 

The DC source of the PSE can not be grounded to the chassis.

802.3 requires isolation between MDI leads and chassis ground.

PoE circuitry is Isolated from the PHY circuitry!

 

We already discussed this issues in the 802.3af and I hope nothing has changed since then.

 

See attached presentation from the 802.3af days in particular slides 10 and 11.

 

Yair

 

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From: owner-stds-802-3-poep@xxxxxxxx [mailto:owner-stds-802-3-poep@xxxxxxxx] On Behalf Of Dove, Dan
Sent: Wednesday, June 14, 2006 8:59 PM
To: STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-POEP] isolation problem

 

Steve,

 

I modified your drawing to address DC isolation requirements of 802.3af.

Dan

 

------------ Previous Message Below ------------

 

 

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From: owner-stds-802-3-poep@xxxxxxxx [mailto:owner-stds-802-3-poep@xxxxxxxx] On Behalf Of Steve Robbins
Sent: Wednesday, June 14, 2006 9:11 AM
To: STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject: [8023-POEP] isolation problem

Sorry, this time the figure is attached.

 

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From: Steve Robbins [mailto:steve@xxxxxxxxxxxxx]
Sent: Wednesday, June 14, 2006 8:59 AM
To: STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject:

 

Guys,

 

I think we have a problem.  See attached diagram.

 

Steve