Many companies aren’t installing any grounding for racks, cabinets and ladder rack making network infrastructure more vulnerable to downtime and equipment failure. Proper grounding of your IT racks and equipment, often called network grounding or grounding infrastructure, is defined by TIA/EIA-942 Telecommunications Infrastructure Standard and goes beyond the requirements of the National Electrical Cod;6e (NEC) to protect equipment and improve system reliability.
The purpose of proper grounding is create a low resistance path to ground and to equalize electrical potentials between racks, data cabinets and ladder rack. The grounding section of TIA-942 offers guidelines that meet the basic principles and adds additional details specific to the modern data center environment. One important issue is the creation of electrical continuity throughout racks and cabinets. Because most racks and cabinets are made of painted components that are bolted together, there is no guarantee that electrical continuity exists from one rack component to the next. In the data center, rack and cabinet continuity is important for safety; electrostatic discharge (ESD) protection; and the proper grounding of switches, servers, and power strips. Continuity may not exist if the installer fails to scrape paint between sections of rack or use specially designed paint-piercing hardware.
Alarmingly, numerous businesses in operation today have grounding busbars in place, and a grid of CBN (common bonding network) conductors under a raised floor, but not a single rack or cabinet bonded to the CBN. It is clear that the owner intended to have grounding; however, if the racks and cabinets are not bonded to the grounding system, then there is no protection. Creating electrical continuity within racks and cabinets is best accomplished during initial installation. This is also the best time to create the bond from the rack to the CBN before it is forgotten. Equipment that is installed on the racks should be bonded at this time.
Key features of a good grounding system should include:
- Permanent copper compression lugs that do not loosen over time;
- Hardware, such as thread-forming screws and paint-piercing washers, thereby creating a metal-to-metal connection (bond);
- Components, such as hardware and jumper cables, that are tested for their ability to create electrical bonds and carry current.