Vce CDCS Questions Latest

When calculatingPower Usage Effectiveness (PUE)in a data center that useschilled water from an external source, like from a building owner, aweight factor for district chilled watermust be applied. This is because PUE calculations aim to measure the energy efficiency of the data center’s own operations, and external utilities like district chilled water aren’t directly powered by the data center. A weight factor of0.4is typically used to account for the energy consumed to produce and deliver the chilled water, reflecting the indirect impact on the data center’s total energy consumption.

Detailed Explanation:

PUE is calculated as the ratio of the total facility energy to the IT equipment energy. If the cooling is provided by an external chilled water source, it’s necessary to adjust the calculations to accurately reflect the energy impact. By incorporating the 0.4 weight factor, data centers can calculate a more accurate PUE, aligning with standard methods and industry best practices.

EPI Data Center Specialist References:

EPI training on PUE highlights the importance of adjusting for external energy sources, such as district cooling, in the calculations. This ensures that PUE values remain accurate and comparable across different data centers, even when external utilities are used.

When installingoverhead data cabling, it’s crucial tomaintain minimum separationfrompower cablesto prevent electromagnetic interference. Additionally, cabling should be arranged so that it does not obstructfire detection and suppression systems, allowing for proper sensor function and suppression agent dispersion in the event of a fire.

Detailed Explanation:

Separation between power and data cabling minimizes the risk of interference and helps ensure compliance with standards for signal integrity. Proper placement relative to fire suppression systems ensures that any smoke or heat can be effectively detected, and suppression agents can be evenly distributed without obstruction from cabling.

EPI Data Center Specialist References:

EPI guidelines emphasize maintaining adequate separation between power and data cables for safety and performance and ensuring cabling does not interfere with essential safety systems in data centers.

Incomputer rooms, replacing awet pipe systemwith apre-action systemis advisable. Pre-action systems provide additional protection by requiring two triggers (e.g., heat and smoke) before water is released, minimizing the risk of accidental discharge and water damage, which is crucial for safeguarding sensitive IT equipment.

Detailed Explanation:

Wet pipe systems contain water in the pipes at all times, which poses a higher risk of accidental discharge. Pre-action systems, however, only fill the pipes with water upon detection of a fire, reducing the risk of water-related damage due to leaks or malfunctions. This approach is considered best practice for environments housing sensitive electronic equipment.

EPI Data Center Specialist References:

EPI advises using pre-action fire suppression in data centers to reduce risks associated with accidental water release, providing a safer and more controlled fire response that better protects critical infrastructure.

A2(N+1) configurationimpliestwo independent UPS systems, each withN+1 redundancy. This configuration provides high availability by ensuring that each UPS system can independently support the load with an additional unit for redundancy. Given the80 kW load, this setup impliesthat two separate N+1 systems are running, providing reliability and fault tolerance for the data center’s power needs.

Detailed Explanation:

TheN+1notation denotes that each system has one additional unit beyond what is needed to carry the load, providing redundancy. With2(N+1), there are two such setups, ensuring that if one fails, the other can still support the load without interruption, fulfilling high availability requirements.

EPI Data Center Specialist References:

EPI teaches that multiple redundant systems, such as2(N+1), enhance data center reliability by ensuring that power is maintained even if a failure occurs in one system. This meets the stringent demands for uptime in critical environments.