27 Apr T-Mobile Digs Deeper

T-Mobile US, Inc. (T-Mobile) commissioned SAE Inc. (SAE) to review existing grounding and provide recommendations for system expansion at their Wayne, New Jersey Switching Center. SAE performed a grounding audit for the existing facility, finding a non-single point interior grounding system with several loops that posed a threat for equipment damage in the event of a power surge or lightning strike. Soil resistivity testing was performed onsite in order to determine the appropriate amount of exterior grounding to achieve the T-Mobile target value of 5 ohms.

In combination with expansion design drawings provided by T-Mobile, SAE designed a single point grounding layout for the existing facility and new expansion. The interior design provided bonding of all equipment in an efficient routing to a new master ground bar. For the exterior grounding, SAE modelled the soil resistivity data and designed a vertical ground well that achieved less than 5 ohms resistance. Upon review of the grounding design and recommendations, T-Mobile awarded the supply and installation for the new grounding to SAE. All interior renovations for grounding, bonding and the installation and connection of the exterior ground well was completed by SAE.

Figure 1: New Master Ground Bar                 Figure 2: Mud Rotary Drill Rig                       Figure 3: Final Resistance Reading

Click here for the Grounding System Drawing.