Computer room static blowing server power supplies

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

In article <Y-(E-Mail Removed)>, "T" <(E-Mail Removed)> 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.

It sounds like your UPS's should take care of everything.
I woulds have the UPS's checked out. I would have building electricians
check things out. I would have installed whole circuit transient protection
at the breaker box feeding the room.

greg

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

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" <(E-Mail Removed)> wrote in message
news:ayBYf.15381$(E-Mail Removed)...
>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
>

"T" <(E-Mail Removed)> schreef in bericht
news:Y-(E-Mail Removed)...
>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
>
>
>


Is ground still connected to good old earth? You'll have to check to be
sure. Suppose the metal of the floor and installation has been grounded
carefully but you'll have to check this too. An open ground connection may
be the cause of you problems. Especially an open connection that is closed
again by someone entering the room.

On all PCs and servers I know, the secondary of the power supply has been
connected to the enclosure which in turn is grounded. So I assume the spark
jumps from the primary of the power supply the the chassis. Looks like
neutral and hot are floating which means that the neutral has not been
connected to ground, at least not properly. (Don't know where neutral should
be grounded in your place.)

There are other possibillities. Did someone install a badly insulated neon
sign near you? Some other renovation maybe? Something else I can't even
imagine but not very likely. I'm pretty sure something is not grounded
properly anymore, but what?

petrus bitbyter

T wrote:
[...]
>
> 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.
>
[...]
> Any ideas would be appreciated.
> TJS

A near identical situation was cured simply by spraying the carpet
tiles in the computer room and access corridor, with anti static
solution.
john

We have ordered some conductive matting for walking on. Waiting for it while
supplies are failing!

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
>T wrote:
> [...]
>>
>> 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.
>>
> [...]
>> Any ideas would be appreciated.
>> TJS
>
> A near identical situation was cured simply by spraying the carpet
> tiles in the computer room and access corridor, with anti static
> solution.
> john
>

My technicians have been testing the grounds to the steel and they are
intact. We have a new fiber pull coming into the room just today via and
existing conduit. The failures have been occuring for almost 2 months but
much more frequently these last 2 weeks.



"petrus bitbyter" <(E-Mail Removed)> wrote in message
news:4432ea11$0$5636$(E-Mail Removed)4al l.nl...
>>
>
>
> Is ground still connected to good old earth? You'll have to check to be
> sure. Suppose the metal of the floor and installation has been grounded
> carefully but you'll have to check this too. An open ground connection may
> be the cause of you problems. Especially an open connection that is closed
> again by someone entering the room.
>
> On all PCs and servers I know, the secondary of the power supply has been
> connected to the enclosure which in turn is grounded. So I assume the
> spark
> jumps from the primary of the power supply the the chassis. Looks like
> neutral and hot are floating which means that the neutral has not been
> connected to ground, at least not properly. (Don't know where neutral
> should
> be grounded in your place.)
>
> There are other possibillities. Did someone install a badly insulated neon
> sign near you? Some other renovation maybe? Something else I can't even
> imagine but not very likely. I'm pretty sure something is not grounded
> properly anymore, but what?
>
> petrus bitbyter
>
>
>

T wrote:
>
> My technicians have been testing the grounds to the steel and they are
> intact. We have a new fiber pull coming into the room just today via and
> existing conduit. The failures have been occuring for almost 2 months but
> much more frequently these last 2 weeks.

I would have the electrical system inspected. The power transformer
for the building may not be properly grounded. The ground rod or wiring
may be damaged, leaving the transformer floating above ground.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

An update; We are investigating "zinc whiskers" phenomina as a possible
cause. The zinc filaments are produced from the plywood core floor panels
supported by the zinc electrocoted support structure. When floor panels are
lifted or disturbed the conductive dust can get into the power supply and
lead to shorts between the modern closely spaced SMT devices.
See here for a white paper http://www.dataclean.com/pdf/zincwhiskers3.pdf

The failures/arcs in our supplies have all arced from the 120vac chopper
regulator collector to the PS case. If the zinc whisker problem is our case
then the blue flash is just a 120/170p-p vac arc to ground, and not a static
discharge.

We are looking at replacing our floor tiles with the modern ultra low static
floor tiles.

I'm a little skeptical that this is the problem, but it is true that 2
months ago we pulled floor tiles to look for fiber conduits and that about
the time the problems began

TJS


"T" <(E-Mail Removed)> wrote in message
news:Y-(E-Mail Removed)...
> 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
>
>
>
>
>