I'm getting 50-60V AC on the cases of our new PoE IP cameras. When I connected one of these cameras are connected to building ground, I actually blew out a...
... For it to be an AC voltage at that amplitude it looks like there is a grounding issue associated with part of the equipment that is mains powered. If it...
Not too sure about blowing the PoE ports, but non earth switchmode power supplies usually have half supply voltage on the -ve terminal when measured with a...
Are there any electrical connections at all to these cameras apart from Ethernet? Is there a terminal provided for connection to local ground? I presume your...
Watched the video and saw why this just does not make sense. Weird. Bounced your link to a bloke I know that builds PoE switches for the entertainment industry...
John He is what I think Your camera is using a non isolated Poe receiver. The Chinese have become notorious for using the simplest forms of Poe receivers, they...
... Well they could try.... There's an incredible amount of deadly stuff being shipped all around the world from Chinese online stores. I recently had the...
... The best in-hand-explosive moment I had was measuring a 6KV power supply with a 7.5KV Tektronics probe. The probe exploded leaving me stunned for lack of...
Thanks to all for the comments! I'm also in communication with Steve Carlson, head of the PoE IEEE committee, and have a couple good comments on the blog. To...
... The Netgear and Linksys switches are powered by external power supplies. They are not earthed. Connect the cases to ground. If the power supply goes bang...
... Video worked this time for me.... In the US one leg is ground and the other hot. Depending on EMI filtering you may see 1/2 line voltage with a very high...
Tangentially, this half-mains to DC negative is what I think is causing a problem with one of my MIDI remotes that a customer reported recently. He said the...
Ground the case. The EMI filters are not intended to run with no ground and the case is probably now broadcasting more EMI than it would have without the...
OK, a little update on the situation. A number of people asked about the integrity of the ground, so I checked that today; http://www.vimeo.com/26042924 Also,...
I uploaded the wrong video for the port blowing out thing--it's fixed now (same link). Two people watched it already... Please watch again ... John ...
... My intended meaning was not that the earth on the multibox is faulty but that the Netgear switch is not connected to it. When I suggested grounding the...
... I had to look at the video three times to grasp where the wires were going. Indeed, what is the voltage on the Netgear case to ground? Pull out the Netgear...
... This is the sort of thing the CPSC (US Consumer Products Safety Commission) lives for. They have determined that ALL products are consumer products and...
The camera is supposed to have its electronics floating, I believe. They are supposed to be able to draw power from either of two pairs of pairs through a...
Ethernet standard requires isolation of 1500Vac between any segment of Ethernet and chassis ground (or any accessible conductor, including connectors to other...
... First, clarifying, my question was entirely tangential and not involving POE. That clear, how is this so if it's a non-grounded PSU? It's an aluminum...
... The EMI filter would be in the power supply, but it should ONLY be there if there's a grounding power plug. I fall into the "burn the wall wort" category....
Sorry for the duplicate if this has already been posted (Gmail really messes up the sort on these kind of discussions), but the support manager from ACTI have...
I agree with jdow, both the camera and switch are faulty - there is no isolation in either. You can't reliably test for isolation using a high-impedance...
That is not technically correct. Isolation and ground have nothing in common. You can have one without the other. John can you post a picture of the wall wart...
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