Data centers, big and small, one rack or twenty, need to achieve unprecedented levels of uptime to keep pace with modern business demands. Proper data and voice system cabling is the first level to achieving uptime goals, and a major part of that system is the network grounding. Proper grounding of the data center improves system reliability and protects equipment. Lightning strikes miles away from a building can generate a surge that will travel through either aerial cables or buried cables to reach electronic equipment. Power surges are a common occurrence and problem.
There are two goals when installing a grounding system. The one everyone immediately thinks about is to create a low resistance path to ground, by carrying that energy away from the equipment to the shortest direct path to an earth ground. The other purpose for the grounding system is to equalize electrical potentials. The goal is to have all conductive materials at the same electrical potential to minimize current flow. Current flows occur when there is a difference in potential between components. If the current flows across a piece of equipment, damage may occur. That means all equipment and all metal materials including racks, cabinets, other enclosures, and ladder racks/cable trays must be bonded to the grounding system. This is going to reduce surging between different parts of the data centers.
The most common mistake in grounding is to daisy chain equipment together. This allows for the entire row of equipment to become energized with stray current, potentially causing damage to all the equipment. Each piece of equipment should have an individual ground to the bus bar, then out to the main building ground. Also, having the correct size ground wire. 6AWG is the TIA 607-B standard for the data center. The larger the wire, the less resistance to ground, the quicker that surge gets away from the equipment. The “up-stream” of the ground service must get larger as well.
The other anomaly proper grounding can defend against is electrical noise in the data center that is introduced on data cables because surges are not correctly dissipated. This noise can create network problems and, even worse, lost data.
Surges, sags, spikes and brownouts are real everyday occurrences. Surge suppressors are another necessary piece of equipment for the data room. Surge suppressors work like a smart power strip. When everything is operating normally at 120/VAC, the power suppressor sends the power to the built in outlets. If a surge happens, the suppressor sends the excess power from the power line directly to the ground. An Uninterruptable Power Supply (UPS) is usually a surge suppressor with batteries, allowing the equipment to continue to operate even in the case of a power failure. The amount of battery storage and how much equipment is attached will determine how much time the system will continue to run. Usually enough time to go and properly shut down the effected equipment.
Most equipment manufacturers will not warranty their equipment for power spikes, so why wouldn’t you want to protect your equipment investment by also including proper grounding techniques, surge suppression, and even UPS in the Server/Telecom Room ?
(Article by Charles Bressler – ECS Account Manager)