EMF Issues and Lead Lined Walls....

[larrybartowski]

A customer is concerned that we are mounting 2 transformers in their "data center" (basically an IT closet). He claims that at their old building they had "interference" to their computers. He went onto say that when they changed to LCD monitors it helped, but they eventually had to install a lead lining in the data center walls. :? Has anyone ever experienced this or have an explanation of what might be happening. I'm debating whether it's worth redesigning the layout of the data rooms. :slaphead: These transformers would be on the load side of the UPS'.

 

[larrybartowski]

He made a comment referencing screens that were 120 hertz vs 60 hertz?

 

[Jraef]

A customer is concerned that we are mounting 2 transformers in their "data center" (basically an IT closet). He claims that at their old building they had "interference" to their computers. He went onto say that when they changed to LCD monitors it helped, but they eventually had to install a lead lining in the data center walls. :? Has anyone ever experienced this or have an explanation of what might be happening. I'm debating whether it's worth redesigning the layout of the data rooms. :slaphead: These transformers would be on the load side of the UPS'.

LOL, "lead lining"... :slaphead:

It's entirely possible (probable) that they were getting what's called "Common Mode Noise" from having an old unshielded transformer. In addition there may have been some EMI / RFI (Electro Magnetic / Radio Frequency Interference) radiating from it as well. The lining could have been any metal, lead was unnecessary, likely expensive, and is now a hazmat. Do not go that route!

You can buy shielded transformers for this purpose to cut down on the common mode noise, but that will not really cut down on the EMI/RFI. If he is really worried about it, he should have the sensitive equipment in a shielded room. So if he has done that, and now you want to introduce transformers into that room, he has a point. But worrying about the transformers if there is already a UPS in the room is like worrying about the dander from fox hair inside of the hen house. That UPS is a HUGE source of EMI/RFI! And if the room is not shielded, the transformers in there will not likely be much worse that anything else.

Read this for some insight.
http://www.interferencetechnology.c...n-the-data-center-to-shield-or-not-to-shield/

 

[JoeStillman]

I have seen CRT monitors shaking in a magnetic field. There was a manufacturer who made a metal box you could put around your monitor. The problem goes away when you replace them with modern LCD or LED monitors. It is very hard to contain the entire magneteic field of a transformer - and almost never necesssary now that LCD monitors are the norm.

As for electro-static fields, my foil hat will never go out of style.

 

[mbrooke]

First, check for wiring errors. Grounded neutrals, crossed neutrals ect.

 

[StarCat]

Interesting

Interesting

I once set a CRT monitor within about 12 inches of an Ampeg 216 bass speaker cabinet.
The field off those speaker magnets totally distorted the image on screen. We moved the cabinet until the field effect ceased.
The IT guy I was hanging with thought it was funny.

I have heard of people stopping EM incursion with those foil mylar blankets. They are all connected together then tied to a ground. May not be effective for strong local fields but they are known to work for some purposes such as RF etc.

Jraef always good information.
Possibly you can comment on the Copper Cages I have seen at a Motorola Facility I used to deal with where they service pagers. Each Tech has his own copper mesh cage. Faraday cage I assume.

 

[GoldDigger]

A Faraday cage will block EM radiation down to a wavelength comparable to the grid spacing in the cage.
It may also block electrostatic fields. It will not block static or slowly changing magnetic fields.