QUESTION: 5

When are the wet bulb and dry bulb temperatures identical?

When the dry bulb's temperature is at the lowest allowable temperature for IT equipment as per ASHRAE
When the dry bulb's temperature is at the highest allowable temperature for IT equipment as per ASHRAE
When the relative humidity is at the best practice value for relative humidity, being 50% RH
When the relative humidity is 100%

Answer(s): D

Explanation:

The wet bulb and dry bulb temperatures become identical when the relative humidity reaches 100%. At this point, the air is fully saturated with moisture, meaning it can no longer absorb additional water vapor. As a result, the rate of evaporation decreases, and there is no difference between the dry bulb and wet bulb temperatures.
Detailed
The dry bulb temperature measures the air temperature, while the wet bulb temperature takes into account the cooling effect of evaporation.
When relative humidity is at 100%, the air has reached its saturation point, and no further evaporation occurs. This causes both the wet bulb and dry bulb thermometers to display the same temperature reading. This condition is critical in understanding environmental conditions, particularly in HVAC and data center environments, where humidity control is essential to avoid equipment overheating or corrosion.
EPI Data Center Specialist

Reference:

The EPI Data Center Specialist training includes understanding humidity levels and their impact on data center environments. Knowing when wet bulb and dry bulb temperatures align helps data center operators manage moisture levels effectively, which is essential for preventing issues related to high humidity, such as condensation on IT equipment.

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QUESTION: 6

A new network storage device in a non-standard size rack of approximately 600 kg/1,300 lbs is going to be installed in the data center.
Are new floor loading calculations required?

No, as long as the equipment is less than 700 kg/1,500 lbs it will be within the limits.
No, specifications of equipment brought into the data center will already be known during the design of the data center, and therefore the floor will be able to handle it.
Yes, additional floor loading calculations need to be done by the floor manager, which should be verified by the safety engineer.
Yes, a structural engineer, approved/endorsed by the building owner, should carry out new floor loading calculations.

Answer(s): D

Explanation:

For heavy equipment, such as a network storage device weighing approximately 600 kg/1,300 lbs, new floor loading calculations are indeed required, particularly since the rack is non-standard. A structural engineer, approved by the building owner, should conduct these calculations to ensure the floor can safely support the new load without risking structural integrity.
Detailed
Data centers are designed with specific floor load ratings, which are determined during the design phase based on anticipated equipment.
When adding or replacing equipment that is significantly heavy or non-standard, reassessing the floor's capacity is essential to avoid overloading. A structural engineer has the expertise to verify if the existing floor can accommodate the weight and, if not, can recommend reinforcement measures.

This step ensures compliance with safety standards and helps prevent damage to the infrastructure, which could lead to costly repairs or even catastrophic failure in extreme cases.
EPI Data Center Specialist

Reference:

EPI Data Center Specialist training advises that any changes in the data center load, particularly involving non-standard and heavy equipment, warrant a structural assessment. Ensuring compliance with floor load capacity is a critical safety and operational concern, as underscoring data center infrastructure reliability and safety is a priority in EPI's best practices.

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QUESTION: 7

A data center has its own power supply from the public utility and receives chilled water supply from the building owner.
What needs to be taken into consideration when calculating the PUE?

Nothing, as the chiller plant in the building also uses electrical power
You will need to take the value for COP of the chiller plant into consideration
You will need to take a weight factor of 0.4 for district chilled water into consideration
PUE calculations are not possible in shared buildings

Answer(s): C

Explanation:

When calculating Power Usage Effectiveness (PUE) in a data center that uses chilled water from an external source, like from a building owner, a weight factor for district chilled water must 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 of 0.4 is 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
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

Reference:

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.

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QUESTION: 8

What is the main reason to install Earth Leakage protection?

Protection of ICT equipment against high-frequency noise currents
Protection of human lives
Improvement of the data center grounding/earthing system
Protection against lightning strikes

Answer(s): B

Explanation:

Earth Leakage Protection is primarily installed to protect human lives by detecting and disconnecting power when a fault current flows to the ground. This type of protection is essential to avoid electrical shock hazards that could occur when insulation fails, or equipment is improperly grounded.
Detailed
Earth leakage currents can occur due to insulation faults or accidental contact with live parts. Earth Leakage Protection systems, such as Residual Current Devices (RCDs), quickly detect these faults and disconnect the circuit to prevent harm to personnel. This is especially crucial in environments like data centers where high-powered equipment is continuously running and any electrical fault can pose significant safety risks.
EPI Data Center Specialist

Reference:

EPI emphasizes that human safety is paramount in data center operations. Proper grounding and leakage protection are fundamental safety measures, and EPI guidelines align with this focus, underscoring the importance of protecting personnel from electrical hazards through appropriate safety systems.

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Free CDCS Exam Braindumps (page: 2)

QUESTION: 5

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QUESTION: 6

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QUESTION: 7

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QUESTION: 8

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