HP DL360 hp ProLiant DL360 generation 3 server high-density deployment - Page 3

HP ProLiant DL360 G3 Server High-Density Deployment Glossary Table 1. Glossary of Power Terms Preliminary Term Description High Voltage 180 - 264 VAC (200-240 VAC nominal) supplied to areas where load requirements are such that high voltage is more economical. Common in commercial applications in North America, numerous foreign countries also use this range as the AC appliance standard. Inrush Current A high, momentary current draw occurring when power is first applied to electrical systems. This current drain is not relative to the power-on requirements of equipment; it is due to the capacitive and inductive properties of components in the power supply. Keyboard/ Video/Mouse Keyboard/video/mouse (KVM) peripherals. A KVM switch is an accessory that switches a single KVM set between two or more server units. Ground Leakage Current Residual current flow through the grounding conductor; always undesirable. With data processing occurring at ever-increasing speeds, most IT equipment these days includes capacitors in the power circuits to filter radio frequency (RF) signals to ground. While effective at filtering RF, these components tend to allow a small amount of AC current to pass to the ground. Leakage current is additive, so that as more equipment is connected to the AC mains, the amount of leakage can increase. Low Voltage 90 - 132 VAC (100-120 VAC nominal) supplied at utility outlets in homes and offices. This is the AC appliance standard used in North America, Latin America, and Japan. Power Density The amount (product) of amps and voltage provided to a system (VA). A 120-VAC 30-amp circuit will deliver a power density of 3600 VA while a 208-VAC 30-amp circuit (single-phase) will deliver a power density of 6240 VA. Power Distribution Unit (PDU) Rack-mounted component that connects directly to the building's AC power infrastructure. The PDU typically provides circuitbreaker protection for groups of AC outlets into which separate AC components of the rack are plugged. Some PDU designs offer primary/secondary switching. Power Factor (Pf) An efficiency rating that indicates the amount of watts actually consumed by a load from the volt-amperes delivered to it. The rating is expressed as either a decimal number between 0 and 1 or percentage of the formula of dividing watts by volt-amperes. A power factor of 1 indicates that a device receiving 1 VA is consuming 1 watt. Power Service Point at where electrical power enters a building or equipment room. continued 3