CDCS Power & Cooling Systems Flashcards

What does PUE (Power Usage Effectiveness) measure in a data center?

Answer: The ratio of total facility power to IT equipment power

PUE is calculated by dividing total facility power consumption by the power consumed by IT equipment, where a value of 1.0 is perfect efficiency.

Which UPS topology provides the highest level of power protection for critical data center loads?

Answer: Double-conversion (online)

Double-conversion (online) UPS continuously converts AC to DC and back, isolating IT equipment from all power anomalies and providing zero transfer time during outages.

What is the primary purpose of a static transfer switch (STS) in a data center power distribution system?

Answer: To provide sub-cycle transfer between two independent power sources

An STS transfers the load between two independent AC sources in less than a half cycle, preventing any detectable interruption to dual-corded equipment.

In data center cooling, what does CRAC stand for?

Answer: Computer Room Air Conditioner

CRAC (Computer Room Air Conditioner) is a unit that monitors and maintains the temperature, air distribution, and humidity in a data center.

What is the recommended approach to prevent hot aisle/cold aisle mixing in a data center?

Answer: Deploy containment systems to separate hot exhaust from cold supply air

Hot aisle/cold aisle containment physically separates hot exhaust air from cold supply air, dramatically reducing recirculation and improving cooling efficiency.

Which power distribution unit (PDU) feature allows administrators to remotely cycle power to individual outlets?

Answer: Switched PDU

A switched PDU allows remote on/off/reboot control of individual outlets via network interface, enabling remote power cycling without physical access.