[c-nsp] Multiple power supply failures. Advise needed

[Seth Mattinen]

Randy McAnally wrote:
> I'm sorry, but I highly doubt this is why his devices are failing.  Each
> device receives ground through the power cord (3rd prong is there for a
> reason, as well it is tied to chassis ground internally).  Secondly, the
> cabinets themselves should be grounded as is the case in any proper facility.
>  By fastening the chasis to the cabinet you are basically providing a second
> ground path.  A third ground path is nice and pretty, but it isn't going to do
> much if anything at all to help him in this case.
> 
> Either the power is extremely dirty, or the facility as a while is not
> properly grounded which means no matter how well he grounds his equipment it
> won't help unless he digs his own ground.
> 

Correct, the ground is the ground is the ground. The lug will let you
beef it up and do a 6AWG or whatever instead of what's in the power
cords, but the ground is tied everywhere. It has to be; it's a safety
ground.

Something really odd/fishy is going on at the facility in question.
Either they have a problem and won't admit it, or they're just as
baffled as you are. But there is obviously *something* very bad going on
to fry power supplies like that.

Which leads me to a question; has any of the stuff you've replaced
become part of the fried PSU problem, or just originally installed
supplies? One tells me they're lying and the power is even worse than a
raw utility feed, the other says maybe you have metal particles (or
something) building up from under the raised floor over time.

~Seth