Large Scale Shielding Project

This new building is the largest in New Jersey with 42 floors of first grade office space under construction. Lower Manhattan is in the background with the statue of liberty to south. Plans for the building included major electrical facilities including three utility transformer vaults on the 14th floor and an extensive Data Center on the 15th floor. Project officials early in the design of the building expressed concern that magnetic fields from the 14th floor electrical equipment may represent an EMI threat to the 15th floor Data Center IT equipment. FMS was engaged to evaluate possible EMI threat concerns.

14th Floor – Multiple Transformer Vaults

This is a floor plan of very extensive electrical facilities planned for construction on the 14th floor. Note three separate utility transformer vaults, each with four 2,500 kVA transformers with attendant collector bus, network protection and cable duct take offs.

14th Floor – West Transformer Vault

This is a closer view of the one of the 14th floor Utility vaults (east side).

15th Floor – Computer Simulation Study

To evaluate the potential magnitude and characteristics of AC magnetic fields likely to be present in areas of the 15th floor Data Center from the 14th floor electrical equipment, FMS constructed a detailed 3-D computer simulation study of the 14th floor transformer vault facilities to predict rough order of magnitude, AC magnetic fields likely to exist at elevations of concern (slab level & +1Meter) in the 15th floor Data Center.

Results of the computer simulation study indicated that peak levels approaching 25 mG would be present in areas of the 15th floor Data Center. While this represents a relatively modest level, project management concluded that absent concrete evidence that the modest AC magnetic field levels did not represent an EMI threat to critical IT equipment or may prove at some future time to be a possible health risk, a decision was made to reduce magnetic field levels to a lower range of values by installation of magnetic field shielding as a precautionary and preemptive measure.

15th Floor – Magnetic Field Shielding

Approximately 4,500 sq/ft of conductive shielding material was installed on three areas of the 15th floor slab by FMS technicians during construction of the building.

15th Floor – Shielding Plate Mounting

Individual conductive plates are mounted to the floor slab.

Bonding Shielding Plates

After all conductive shielding plates are attached to the floor surface, seams between individual plates are electrically bonded together utilizing an FMS proprietary welding procedure.

15th Floor – Completed Shielded Area

Shielding installation in one of the three areas nears completion with three FMS technicians completing the welding & bonding procedure.

15th Floor – Post Shielding Results

AC magnetic field spot measurements were subsequently documented throughout the 15th floor Data Center after shielding installation was completed and typical representative electrical loading conditions were present in the operation of the 14th floor electrical equipment. Spot measurements as shown here on the east side of the 15th floor, confirmed that AC magnetic field levels had been comfortably reduced well below the 3 to 5 mG target range