HP ProLiant SL270s HP ProLiant SL Servers Planning Guide - Page 22

Power consumption Power consumption can be divided into two broad categories: • Marked electrical amperage, which is listed on the required safety and regulatory labels, generally represents the maximum current draw that the marked device could achieve. Safety and regulatory labels on computer equipment list the ratings for maximum power consumption conditions. • Typical consumption, which is measured under normal circumstances, should be used only in customer calculations with UPS and air conditioning sizing where remaining capacities are needed. When determining the necessary electrical infrastructure required, consider several factors. The first and most important area is the local electrical and regulatory codes. The installation must meet or exceed these codes. The local authority has jurisdiction and makes the final decision as to whether an installation conforms to the relevant codes. In North America, the relevant code is National Electrical Code 2005 Article 210 and Article 645, which states the continuous measured load must not exceed 80 percent of the rated circuit maximum, where continuous load is defined as 3 hours or more. This method leaves some flexibility to the infrastructure designer and includes several options for determining power requirements, which are discussed in the following bullets. NOTE: The following scenarios use North America circuit sizes and voltages. • Use HP power sizing tools to calculate the infrastructure required as configured and allow some flexibility for growth. HP provides power sizing tools for all its current industry standard servers at the HP Enterprise Configurator website (http://h30099.www3.hp.com/configurator/). This tool provides a conservative estimate of power loading values at a given system utilization as well as a theoretical maximum load that the system could achieve as configured. Use of these tools allows the infrastructure designer to use realistic maximum values to estimate power loading and circuit requirements. In this scenario, however, monitoring tools such as Insight Power Manager or HP Monitored PDUs must be used to ensure that the continuous loads do not exceed 80 percent of the rated circuit load. • Install devices in a test environment and measure the actual worst case loads running the applications and loading that is specific to your environment, and then size the electrical infrastructure accordingly. This method is the most accurate, but it might not be practical for many customers. This method also requires ongoing monitoring of the installation to ensure that infrastructure is not overloaded as applications and loads change. • Manage the electrical load using the HP ProLiant SL Advanced Power Manager. For information about SL APM, see the HP ProLiant SL Advanced Power Manager User Guide on the HP website (http://h20000.www2.hp.com/bc/docs/support/SupportManual/c02018322/c02018322.pdf?j umpid=reg_R1002_USEN). • Size air conditioning and UPS devices with typical ratings, but account for overloading that might take place with additional infrastructure growth. HP recommends a cooling plan for the maximum rated power output of the room and a growth plan for cooling the infrastructure. When determining power requirements, always consider any peripheral equipment that will be installed during initial installation or as a future upgrade. To determine the power required to support these devices, Power requirements and considerations 22