QUESTION: 17

The data center has been in operation for about 1 year and 2 months. The dust levels in the computer room are relatively high.
What is the most likely root cause?

The cleaning crew is not doing their work properly
Every computer room has high dust levels due to constant high-speed air movement
Low pressure in the computer room
Floorboards are most likely not fitted correctly

Answer(s): D

Explanation:

High dust levels in a computer room are often due to improperly fitted floorboards.
When floorboards are not securely installed or do not fit tightly, they allow dust and particles from the subfloor to enter the room. In a data center, this can lead to high levels of dust that affect air quality and equipment performance.
Detailed
Raised floors in data centers can accumulate dust and debris, especially if the floorboards are not properly sealed. Loose or improperly fitted floorboards allow contaminants from the subfloor to enter the data center environment, increasing the dust levels over time. Proper installation and maintenance of floor panels are essential to prevent dust infiltration and maintain clean conditions.
EPI Data Center Specialist

Reference:

EPI training emphasizes proper flooring installation and maintenance to control air quality within data centers. Correctly fitted floorboards prevent dust accumulation from the subfloor, which helps protect sensitive equipment and maintains a cleaner environment.

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QUESTION: 18

You have three UPS systems connected in parallel. The UPS systems have an imbalance in the load sharing of approximately 20%.
What should you recommend?

Review the cable lengths of each UPS to the common busbar
Nothing, there is no reason for any concern
Review the common mode noise levels within the computer room
Review the harmonics levels within the computer room

Answer(s): A

Explanation:

An imbalance in load sharing between UPS systems connected in parallel can often result from unequal cable lengths to the common busbar. If the cabling from each UPS to the busbar varies significantly in length, it can lead to differences in impedance, resulting in uneven load distribution. Ensuring that cable lengths are consistent helps to balance the load sharing across the UPS systems.
Detailed
Parallel UPS systems rely on uniform impedance to share loads evenly. Differences in cable lengths cause variations in resistance, leading to one or more UPS units carrying a disproportionate share of the load. Standardizing cable lengths ensures equal impedance, which promotes balanced load sharing and prevents one UPS from being overburdened, thus maintaining overall system reliability.
EPI Data Center Specialist

Reference:

EPI guidelines recommend checking cable lengths when load imbalances occur in parallel UPS configurations. Ensuring equal lengths is a common method to resolve impedance issues that affect load distribution, which is critical for the stable operation of redundant power systems.

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QUESTION: 19

You are working on the design of a new facility. The electrical riser of the building with high current power is located close to the area where sensitive IT equipment in the computer room will be located.
What should you recommend to reduce the amount of EMF coming from the electrical riser?

Install single-phase power cabling
Install three-phase power cabling based on three individual core wires
Install bus bar trunking
Install three-phase power cabling based on a combined cable (e.g. XLPE etc.)

Answer(s): D

Explanation:

To reduce Electromagnetic Fields (EMF) emanating from the electrical riser near sensitive IT equipment, three-phase power cabling in a combined cable (such as XLPE) is effective. Combined cabling helps reduce EMF by keeping the conductors tightly packed, which minimizes magnetic fields generated by current flow. Cables like XLPE (cross-linked polyethylene) also offer better insulation, which helps mitigate EMF interference with nearby IT equipment.
Detailed
Using a combined three-phase cable reduces EMF because the magnetic fields generated by each phase tend to cancel each other out when in close proximity. This arrangement helps reduce the overall magnetic field strength. In addition, XLPE and similar materials provide good insulation, making them a preferred choice for reducing EMF emissions around sensitive equipment.
EPI Data Center Specialist

Reference:

EPI data center best practices recommend mitigating EMF interference through combined cabling arrangements, especially near areas where sensitive IT equipment is located. Reducing EMF is crucial to maintaining equipment reliability and ensuring compliance with safety standards.

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QUESTION: 20

The location of a data center is just above the Arctic Circle (North Pole). The outside air temperature is never above 21°C/70°F.
Taking energy efficiency as the highest priority, which cooling system should you recommend?

Standard air conditioning units, as spares might not be readily available
Any cooling system can be efficient because the outside air temperature will not influence the temperature of the air intake of the ICT equipment
Waterside economizer
Airside economizer

Answer(s): D

Explanation:

In locations with consistently cold temperatures, such as above the Arctic Circle, an airside economizer is the most energy-efficient cooling solution. Airside economizers use cool outside air to lower indoor temperatures, reducing or even eliminating the need for mechanical cooling. Given the consistently low temperatures, this method maximizes energy efficiency by leveraging natural cooling.
Detailed
Airside economizers are ideal in environments where outside temperatures are consistently low. By drawing in and filtering cold outdoor air, they directly cool the indoor environment, thereby reducing energy consumption significantly compared to traditional air conditioning. This cooling approach aligns with energy efficiency goals by minimizing mechanical cooling demands.
EPI Data Center Specialist

Reference:

EPI recommends the use of airside economizers in cold climates to achieve high energy efficiency, as they allow data centers to capitalize on ambient conditions for cooling, aligning with sustainability and cost-saving practices.

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Free CDCS Exam Braindumps (page: 5)

QUESTION: 17

Explanation:

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QUESTION: 18

Explanation:

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QUESTION: 19

Explanation:

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QUESTION: 20

Explanation:

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