The demand for more rack power has been increasing. Average rack power is expected to soon double to 12.0 kW from an average of 6.0 kW in 2006. To meet these power demands, some companies already have hardwired racks capable of providing up to 30 kW.
Distributing 400V of power directly from power panels to the rack to support the high-power needs of high-density servers and network storage devices is becoming an accepted practice for data centers of all sizes worldwide. The 400V three-phase power is connected to two Raritan rack iPDUs, which supply each server with 230V single-phase power—within the operating range of nearly all IT equipment power supplies. 480V/277V designs are also available for next-generation data center cloud and enclosure designs.
Maintaining 400V power to rack IT equipment is more energy-efficient, as it eliminates the need for step-down voltage conversions and the associated transmission losses along the power circuit. Compared to 208V distribution, 400V reduces energy costs by approximately 2–3%.
There are several advantages to distributing three-phase high-voltage power to equipment housed in data center racks. Operating at high voltage at lower current means fewer cables, simplifying deployment, and smaller cables: less copper consumption, lighter weight, less space, and lower cost. This results in less air obstruction under the floor and improved cooling.
High-power rack monitoring:
Raritan's iPDUs offer real-time monitoring of the data center environment to maintain the health of IT equipment and racks. User-configurable critical and non-critical power and environmental thresholds can be set, and alerts can prompt data center administrators to take corrective action. Raritan's family of smart PDUs collects comprehensive and accurate power information, including data on voltage, current (amps), power factor, apparent power (kVA), active power (kW), ambient temperature and humidity, air pressure and flow, and energy consumption in kilowatt-hours (kWh).
When moving to higher power racks with higher rack inlet temperatures, care must be taken to ensure adequate cooling without over-cooling. Raritan offers optional sensors—which connect to the iPDUs and require no additional network connections—to monitor rack temperature and humidity. Users can define thresholds and receive alerts when thresholds are crossed for environmental events such as hot spots or over-cooling.
• Short-circuit monitoring – If the incoming current at a rack PDU is greater than the current at the rack PDU's output points, Raritan installs a short-circuit breaker for each output group. Unlike some PDU vendors, Raritan ensures that each circuit is independently protected and monitored to improve reliability and operational flexibility. The iPDU monitors the breakers and sends alerts. Three-phase iPDUs monitor all three lines and send alerts if any lines become unbalanced.
• Output Level Monitoring – Raritan rack-mounted iPDUs provide accurate power consumption data for every power supply, for every server. Precisely meeting ISO/IEC billing-grade standards, Raritan PX iPDUs provide +/-1% kWh accuracy for every individual asset in the data center. Built to IT and facility standards, the PX iPDU can pass this information upstream to build real-time asset monitoring and management systems.
All PX models are fully compatible with Raritan Power IQ® software, which provides additional control and management capabilities to show which devices are consuming more power, whether energy-saving efforts are working, and whether there are hotspots or undercooled areas. Enterprise-wide, data collected by Raritan smart PDUs, third-party rack-mounted PDUs, and online meters allows Power IQ analytics to calculate and plot active power, energy consumption, cost, and size for servers and other IT devices.
