[AusNOG] Rack Studs - AWESOME

[Peter J. Cherny]

>> On Thu, Jan 2, 2014 at 10:51 AM, Andrew Jones <aj at jonesy.com.au
>> <mailto:aj at jonesy.com.au>> wrote:
>> Wouldn't any kit sharing a common ground (via the PDU) be OK? I
>> guess if your devices are powered via DC plug packs it would be a
>> different story.
> On 01/02/14 14:06, Damian Guppy wrote:
> The earthing pin on a PDU cable (ie power cable) should not be treated
> as a common ground, and in fact should not be connected to the casing /
> chassis of any equipment internally. That is why you will still see
> ground points on a lot of gear (particularly from Cisco)

AS 3000 and AS S009 suggest otherwise !

<flame>
Any suggestion that the earth leg "should not be connected to the 
casing/chassis"
is a recipe for DEATH by electrocution.
A bit like cutting off the earth pin on the home hifi to fix the hum.
</flame>

People confusing safety and signal grounding schemes has been an ongoing 
problem
as long as I can remember (40+ years)
but has always been understood by telecommunication engineers.

Best practice is now well enshrined in the various electrical and 
telecomms standards.

Keywords of interest "equi-potential point" "reference ground" 
"sacrificial earth" "common-mode noise"