This was th 1st thing we fixed. The RH was 15%, we raised it to 45% (its
winter). The adjacent control rrom is around 15% .
TJS

"Ban" wrote in message
...
T wrote:
A raised floor server room with 6 servers, fiber optic patch panels,
large control system cabinets and large UPS system, has been recently
been plagued by computer power supply failures. The supplies fail
when apparently many tens of thousands of volts jump from inside the
PS around the switching regulators to the chassis of the supply
taking out all the components. This has happened to 8 supplies so
far. A visible blue flash has been witnessed several times by
pewrsons in the room.
The servers so far affected are all sitting on the raised computer
center floor. What ususally happens seems to be when a person enters
the 12x20ft room or gets near a server a large snap is heard and the
server is on the backup redundant PS, if it has not already failed.

We have been adding grounding bonding from all computer case to the
bldg steel, raised floor structure, etc to try to stop this. Its
still happening. The computers are various brands and varoious ages,
from 1 week old to 5 years old. The probelm began occuring 2 months
ago. The data center was built 12 years ago.

We are at a loss to figure out how the charge is building up on the
inside of the power supplies. I am thinking about the common power
source, via the power cords Hot, Neutral and Ground conductor.

The green wire should be bonded to the PC case. Apparently the PS
regulator board floats above chassis potential. Apparently a large
potential differnce is building. It jumps a 1 inch gap to the
chassis. Burn marks from repeated arc overs are evindent (the arc
that makes it fail is not the 1st time it occurs!)

The Hot and Nuetral..how could a charge be coming in on these
conductors and getting past the MOVs to build a potential on the
boards.

Any ideas would be appreciated.
TJS

Put a humidifier inside the room, the air is too dry and static
electricity builds up.
--
ciao Ban
Apricale, Italy