HP 10622 Best practices for HP 10000 Series and HP 10000 G2 Series Racks - Page 22

Grounding and Earth leakage current For proper operation and safety, rack components must be properly grounded in accordance with any local and regional building codes. Furthermore, make sure that all power distribution devices used in the installation, such as branch wiring and receptacles, are Listed or Certified grounding-type devices. Because of the high ground-leakage currents associated with multiple servers connected to the same power source, a reliable grounded (earthed) connection is essential. HP recommends the use of a PDU that is either permanently wired to the building's branch circuit or is provided with a nondetachable cord that is wired to an industrial style plug. National Electrical Manufacturers Association (NEMA) locking-style plugs or those complying with International Electro technical Commission (IEC) 60309 are considered suitable for this purpose. HP does not recommend using common power outlet strips for this equipment. Observe the following limits when connecting the product to AC power distribution devices: • For UPS products and PDUs that have permanently attached AC power cords or are directly wired to the building power, the total combined leakage current should not exceed 5 percent of the total input current required for the connected products. • For UPS products and PDUs that have detachable AC power cords, the total combined leakage current should not exceed 3.5 mA per PDU or UPS. Additional resources A power calculator is available at http://h30099.www3.hp.com/configurator/calc/Power Calculator Catalog.xls. Also available is a ProLiant Rack/Site Installation Utility for purposes of reviewing the server loading to determine the number of power supplies for the power supplies to be redundant and approximate the electrical and heating load per server for facilities planning. The ProLiant Rack/Site Installation Utility is available at http://h30099.www3.hp.com/configurator/calc/Site Preparation Utility.xls. There is also a quick reference power cord matrix available at ftp://ftp.compaq.com/pub/products/servers/proliantstorage/power-protection/powercordmatrix.pdf. Equipment clearance and floor loading A clearance of 48 inches in front of a configured rack and 30 inches to the rear of a configured rack is recommended. All buildings and raised computer room floors are engineered to provide a specific floor loading. WARNING When configuring a solution, make sure that the floor loading specifications are followed. Failure to do so may result in physical injury or damage to the equipment and the facility. 20