Exin CDCS Exam Practice Test Instant Access

Question 1

You are allowed to use a calculator for this question. A battery bank is rated at a total capacity of 600 Ah. Calculate how much charging current the rectifier should be able to supply as charging current.

A12 Amperes

B30 Amperes

C60 Amperes

D80 Amperes

Answer : B

To determine the charging current for a battery bank, a general rule of thumb is that the charging current should be 5% of the total battery capacity. For a battery rated at 600 Ah, this calculation would be:

600Ah0.05=30Amperes600 \, \text{Ah} \times 0.05 = 30 \, \text{Amperes}600Ah0.05=30Amperes

This ensures the battery is charged efficiently without overloading the rectifier or risking battery damage.

Detailed Explanation:

Battery charging current is typically set as a percentage of the battery's capacity to balance effective charging with longevity and safety. A 5% charging rate is standard for lead-acid batteries, which would be 30 Amperes for a 600 Ah battery bank.

EPI Data Center Specialist References:

EPI standards recommend calculating charging currents based on a percentage of the battery capacity to ensure safety and efficiency, aligning with best practices for battery management in data centers.

Question 2

In order to save energy, you are going to install an automated system to switch off lights. What should be taken into consideration when installing such a system?

ASecurity guards should perform regular inspections verifying the system works.

BThe system should not be based on motion detection as the lights might suddenly switch off while staff is still at work.

CIt is not advisable to use such a system since it will reduce the lifetime of LED lighting.

DAt all times, the levels should allow for security cameras to function properly.

Answer : D

When installing an automated lighting system, especially in a security-sensitive area like a data center, it's essential to ensure that lighting levels support security camera functionality at all times. Sufficient lighting is necessary for cameras to capture clear footage, ensuring continuous monitoring and security regardless of occupancy.

Detailed Explanation:

Automated lighting based on occupancy or time settings can reduce energy costs, but it must be configured to maintain adequate illumination for surveillance. Security cameras require minimum lighting levels to operate effectively, so lighting should be configured to avoid compromising security.

EPI Data Center Specialist References:

EPI emphasizes security and safety in data centers, advising that lighting systems should maintain levels conducive to effective surveillance, ensuring operational security even when lights are automatically controlled.

Question 3

You are allowed to use a calculator for this question.

A computer room has a net volume of approximately 2,500 m / 88,287 ft.

The temperature is 20 C / 68 F.

The required design concentration is 7%.

The S-Factor is 0.1359 (metric) / 1.885 (imperial).

Calculate the amount of gas required for this computer room based on FM200. What is the correct weight?

AApproximately 410 kg / 900 lbs

BApproximately 820 kg / 1,800 lbs

CApproximately 1,390 kg / 3,000 lbs

DApproximately 1,640 kg / 3,600 lbs

Answer : B

The amount of FM200 gas required can be calculated using the formula:

WeightofGas=NetVolumeDesignConcentrationS-Factor\text{Weight of Gas} = \text{Net Volume} \times \text{Design Concentration} \times \text{S-Factor}WeightofGas=NetVolumeDesignConcentrationS-Factor

Using metric units:

Net Volume: 2,500 m

Design Concentration: 7% (or 0.07)

S-Factor: 0.1359

Calculation:

2,500m30.070.1359=821.325kg2,500 \, \text{m}^3 \times 0.07 \times 0.1359 = 821.325 \, \text{kg}2,500m30.070.1359=821.325kg

Rounded to the closest answer: 820 kg

In imperial units:

Net Volume: 88,287 ft

S-Factor: 1.885

Calculation:

88,287ft30.071.885=1,165.27lbs88,287 \, \text{ft}^3 \times 0.07 \times 1.885 = 1,165.27 \, \text{lbs}88,287ft30.071.885=1,165.27lbs

Rounded, this is approximately 1,800 lbs.

EPI Data Center Specialist References:

EPI instructs on using specific formulas and S-factors provided by manufacturers for each gas type, ensuring that calculations reflect the correct concentration for the given room volume.

Question 4

What should be considered when installing overhead data cabling?

ATo maintain minimum separation from power and ensure that the fire detection and suppression systems are not hindered.

BCopper data cabling should not be placed in metal cable trays.

COptical fiber cabling should always be positioned on top of the copper cabling in the same cable tray to avoid damage to the sensitive optical fiber.

DAll cabling should make sharp bends directly into the rack to avoid usage of additional space and blocking the airflow on top of the rack.

Answer : A

When installing overhead data cabling, it's crucial to maintain minimum separation from power cables to prevent electromagnetic interference. Additionally, cabling should be arranged so that it does not obstruct fire 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.

Question 5

You are changing the design of the fire suppression system for your computer room from a halocarbon fire suppression system into an inert-based fire suppression system. Could you use the same formula to calculate the gas content for the gas?

ANo, there is a significant difference in the formula for the different types of fire suppression gases.

BYes, as long as you take the difference between the net and gross volume into account.

CYes, as long as you use the same units of measure, i.e., kg/m or lbs/ft.

DYes, as long as you change the 'S' factor of the formula to reflect the gas type used.

Answer : A

The formula used to calculate the gas content differs significantly between halocarbon and inert-based fire suppression systems. Halocarbon systems function by absorbing heat, while inert systems work by reducing oxygen levels. Due to these differences in fire suppression mechanisms, distinct formulas are applied, factoring in the specific properties of each gas type and the required concentration levels.

Detailed Explanation:

Halocarbon systems like FM200 require a formula that accounts for the concentration needed for cooling, while inert gases like nitrogen or argon need a formula that calculates the volume based on oxygen displacement. As the design concentration and characteristics of these gases differ, it's essential to use the correct formula specific to the gas type.

EPI Data Center Specialist References:

EPI recommends consulting the specific design requirements and formulas provided by each gas manufacturer when switching fire suppression systems to ensure the correct amount of gas is deployed for effective fire suppression.

Question 6

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?

AThe cleaning crew is not doing their work properly

BEvery computer room has high dust levels due to constant high-speed air movement

CLow pressure in the computer room

DFloorboards are most likely not fitted correctly

Answer : D

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 Explanation:

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 References:

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.

Question 7

A data center scores Rated-3 in mechanical, Rated-4 in electrical, and Rated-2 in architectural.

What is the overall Rating of this data center when the Rating is based on the ANSI/TIA-942?

ARated-2 since that is the lowest rating received

BRated-4 since that is the highest rating received

CRated-4 since electrical is more important than mechanical and architectural

DDepends on the Rating scored in telecommunications

Answer : A

According to ANSI/TIA-942 standards, the overall data center rating is determined by the lowest rating among all evaluated categories. Therefore, if a data center is rated 2 in architectural, despite being rated higher in mechanical and electrical, the overall rating is Rated-2. This approach ensures that all aspects meet a minimum standard and prevents a higher rating if any critical area does not comply.

Detailed Explanation:

ANSI/TIA-942 evaluates data centers across several areas, including mechanical, electrical, architectural, and telecommunications. The overall rating reflects the lowest rated category, ensuring that no aspect of the data center's design or operation falls below the specified level. Thus, in this case, the architectural rating of 2 dictates the final rating, ensuring a comprehensive and balanced assessment of reliability and resilience across all aspects.

EPI Data Center Specialist References:

EPI Data Center Specialist training aligns with ANSI/TIA-942, stating that the final rating must reflect the lowest score to ensure comprehensive reliability across all critical infrastructure categories. This avoids overstating the data center's resilience and ensures uniform standards across areas.

Exin EPI Certified Data Centre Specialist Exam Practice Test