Unique Top-selling CDCS Exams - New 2026 EXIN Pratice Exam
EPI Data Centre Dumps CDCS Exam for Full Questions - Exam Study Guide
EXIN CDCS Exam Syllabus Topics:
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NEW QUESTION # 43
Is it allowed to make design changes during the implementation phase?
- A. Any change is fine as long as it is within the scope of the project.
- B. No, after a design freeze no further changes are allowed.
- C. Yes, but only when time to implement is not exceeded.
- D. Only when there is a strong business and/or technical justification.
Answer: D
Explanation:
Design changes during the implementation phase are generally allowed only when there is a strong business and/or technical justification. Changes at this stage can lead to delays, increased costs, or compromise design integrity. Thus, a rigorous assessment is required to ensure any modifications are essential and provide clear benefits or address critical issues.
Detailed Explanation:
Changes post-design freeze should be minimized to avoid scope creep and additional costs. However, if a technical issue arises that would affect operational goals, or a business need warrants modification, justified changes are permissible, following an impact assessment and approval process.
EPI Data Center Specialist References:
EPI project management guidelines recommend a controlled change management process during implementation, allowing changes only when they align with critical objectives or address unforeseen issues that affect the project's success.
NEW QUESTION # 44
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?
- A. Depends on the Rating scored in telecommunications
- B. Rated-4 since electrical is more important than mechanical and architectural
- C. Rated-2 since that is the lowest rating received
- D. Rated-4 since that is the highest rating received
Answer: C
Explanation:
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.
NEW QUESTION # 45
Smoke sensors must be installed in the computer room. What is the minimum density?
- A. 1 per 5 m²
- B. 1 per 25 m²
- C. 1 per 10 m²
- D. 1 per 40 m²
Answer: B
Explanation:
NFPA 75 (Standard for IT Equipment Protection) and NFPA 72 (Fire Alarm Code) recommend installing at least one smoke detector per 250 ft² (#25 m²) in IT rooms. This ensures early detection in high-value environments.
* A and B are far too dense, exceeding NFPA minimums.
* D is too sparse and would not meet early detection requirements.
Therefore, the correct standard density is 1 per 25 m².
References: NFPA 75 §5.4.3, NFPA 72 Table 17.6.3.5.1.
NEW QUESTION # 46
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.
- A. 30 Amperes
- B. 12 Amperes
- C. 80 Amperes
- D. 60 Amperes
Answer: A
Explanation:
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:
600 Ah×0.05=30 Amperes600 \, \text{Ah} \times 0.05 = 30 \, \text{Amperes}600Ah×0.05=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.
NEW QUESTION # 47
When installing a raised floor, can we use a spirit level bar to level the floor?
- A. Yes, spirit level bars can be used as long as their length is longer than 60 cm/2 ft (the size of a typical raised floor tile).
- B. Yes, using a spirit level bar for raised floors higher than 40 cm is preferred.
- C. No, because using a spirit level bar, a measurement error will be transferred from pedestal to pedestal.
- D. Yes, but spirit level bars can only be used in the vertical plane.
Answer: C
Explanation:
A spirit level bar should not be used for leveling a raised floor, as measurement errors are likely to propagate from one pedestal to the next. Spirit levels can introduce cumulative errors, leading to uneven floors, particularly in large installations where precise leveling is critical.
Detailed Explanation:
Using a laser level or a precision leveling device is recommended to ensure accuracy across all floor tiles. Spirit levels, while adequate for short spans, can transfer small inaccuracies from one pedestal to another, which can cause alignment issues and floor instability over time.
EPI Data Center Specialist References:
EPI data center guidelines discourage the use of spirit levels for raised floors. Instead, they advocate for precision tools like laser levels that ensure consistency and accuracy in large-scale installations, aligning with best practices for raised floor construction.
NEW QUESTION # 48
What is the effect of having a damper (in open position) construction in a raised-floor tile?
- A. Dampers allow for a higher supply air temperature
- B. Dampers reduce the air volume by approximately 10%
- C. Dampers can be used when there is a high rate of temperature change in the computer room
- D. Dampers increase the air volume by approximately 10%
Answer: B
Explanation:
Perforated tiles with integrated dampers are common in raised-floor data centers because they allow airflow regulation at the rack level. However, even when the damper is fully open, the mechanism inside the tile restricts airflow. This typically reduces the delivered airflow by around 10% compared to a non-dampered tile of the same type.
* Option A is incorrect because dampers do not affect supply temperature; they only throttle volume.
* Option B is wrong since dampers cannot increase volume-they only add resistance.
* Option D is partially true that dampers help with temperature balancing, but the main effect (in open position) is volume reduction.
Thus, the technical impact of dampers in open position is a slight airflow reduction, usually quantified as
~10%.
References: ASHRAE TC 9.9 - "Airflow Management in Raised-Floor Environments," ANSI/TIA-942-B §6.
5 (Cooling Infrastructure).
NEW QUESTION # 49
What is a disadvantage of hypoxic-based fire suppression?
- A. Only usable with positive pressure rooms
- B. Gas containers must be close to hazard
- C. Only usable in rooms with sufficient air changes
- D. Only usable in non-occupied areas
Answer: D
Explanation:
Hypoxic systems continuously lower oxygen concentration (~15%) to prevent combustion. While safe for short-term human exposure, standards like ISO 20338 recommend they are not suitable for continuously occupied spaces, because reduced oxygen may cause fatigue, reduced cognition, and health risks for staff.
* B is irrelevant-air change rates affect dilution, not feasibility.
* C is incorrect-tanks can be remote.
* D is false-positive pressure is not required.
Thus, the main disadvantage is restriction to non-continuous occupancy.
References: ISO 20338 (Oxygen Reduction Systems), NFPA 770.
NEW QUESTION # 50
What should be considered when installing overhead data cabling?
- A. Copper data cabling should not be placed in metal cable trays.
- B. To maintain minimum separation from power and ensure that the fire detection and suppression systems are not hindered.
- C. All cabling should make sharp bends directly into the rack to avoid usage of additional space and blocking the airflow on top of the rack.
- D. Optical 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.
Answer: B
Explanation:
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.
NEW QUESTION # 51
What is the minimum requirement for the power feeds to the building for a Rated-3 data center based on the ANSI/TIA-942 standard?
- A. Two feeds coming from two different substations, one power company is acceptable
- B. One feed from one substation split over two separated distribution boards in separate rooms
- C. Two feeds entering the data center building from one substation
- D. Two feeds coming from two different substations, one power company is not acceptable
Answer: A
Explanation:
The minimum requirement for power feeds to a Rated-3 data center according to ANSI/TIA-942 is to have two independent power feeds, which can come from two different substations provided by the same power company. This ensures redundancy and concurrent maintainability, as each feed can support the load independently during maintenance or failure of the other.
Detailed Explanation:
The separation by two substations ensures resilience in case of a localized outage or substation maintenance, aligning with Rated-3 requirements for uninterrupted operation. ANSI/TIA-942 permits these feeds from a single utility provider as long as they are supplied from distinct substations.
EPI Data Center Specialist References:
EPI underscores the importance of dual power feeds from separate substations for Rated-3 facilities, highlighting that the ability to draw from different substations aligns with redundancy requirements for high availability.
NEW QUESTION # 52
You are allowed to use a calculator for this question.
A computer room has a net volume of approximately 2,500 m³ / 88,287 ft³.
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?
- A. Approximately 1,390 kg / 3,000 lbs
- B. Approximately 410 kg / 900 lbs
- C. Approximately 1,640 kg / 3,600 lbs
- D. Approximately 820 kg / 1,800 lbs
Answer: D
Explanation:
The amount of FM200 gas required can be calculated using the formula:
Weight of Gas=Net Volume×Design Concentration×S-Factor\text{Weight of Gas} = \text{Net Volume}
\times \text{Design Concentration} \times \text{S-Factor}
Weight of Gas=Net Volume×Design Concentration×S-Factor
Using metric units:
* Net Volume: 2,500 m³
* Design Concentration: 7% (or 0.07)
* S-Factor: 0.1359
Calculation:
2,500 m3×0.07×0.1359=821.325 kg2,500 \, \text{m}^3 \times 0.07 \times 0.1359 = 821.325 \, \text{kg}2,500 m3×0.07×0.1359=821.325kg Rounded to the closest answer: 820 kg In imperial units:
* Net Volume: 88,287 ft³
* S-Factor: 1.885
Calculation:
88,287 ft3×0.07×1.885=1,165.27 lbs88,287 \, \text{ft}^3 \times 0.07 \times 1.885 = 1,165.27 \, \text{lbs}
88,287ft3×0.07×1.885=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.
NEW QUESTION # 53
It is assumed that EMF shielding material must be installed as the EMF levels coming from the transformer room into the computer room are measured at 100mG. The transformer room is approximately 10 meters away from the computer room and is separated by a corridor. You can assume that no physical issues are present for installing shielding material at any area/location.
Where should you recommend the shielding material to be installed?
- A. Shielding is not required to be installed as 100mG is within the acceptable levels for computer rooms
- B. As close as possible to the computer room
- C. As close as possible to the transformer room
- D. It does not matter, either close to the transformer room or the computer room is okay as there is no impact to cost or shielding material performance
Answer: C
Explanation:
EMF shielding is most effective when installed close to the source of the EMF, which in this case is the transformer room. Shielding at the source contains the magnetic fields before they spread, minimizing exposure throughout the facility, including the computer room.
Detailed Explanation:
Placing shielding close to the EMF source minimizes the area impacted by electromagnetic interference, as it reduces the distance over which the EMF can spread. Shielding materials near the source can absorb or redirect EMF, providing the most effective reduction of EMF levels in adjacent spaces, like the data center.
EPI Data Center Specialist References:
EPI data center training advises positioning shielding close to the EMF source to contain fields more effectively and reduce interference in critical areas. This method is more efficient and cost-effective, as it limits the spread of EMF from the point of origin.
NEW QUESTION # 54
The temperature in the computer room is being increased from 18°C/64°F to 27°C/81°F.
What is the impact, if any, on the amount of gas required to suppress a fire assuming the gas is a Halocarbon?
- A. The change to the amount of gas cannot be determined without knowing the change in humidity as well
- B. The amount of gas required will be higher
- C. The amount of gas required will be lower
- D. The amount of gas required will not change
Answer: C
Explanation:
With Halocarbon fire suppression systems, as the temperature increases, the amount of gas required for effective suppression decreases. This is because Halocarbon agents are stored as a liquid and discharge as a gas, expanding more at higher temperatures. As a result, less agent is needed at higher room temperatures to achieve the desired concentration for fire suppression.
Detailed Explanation:
Halocarbons rely on specific volumetric concentrations to suppress fires. Higher temperatures cause the agent to expand more rapidly, effectively filling the protected area with less agent needed to reach the required concentration. This is in contrast to some other gases, where temperature changes might not have the same effect on discharge quantities.
EPI Data Center Specialist References:
EPI data center training on fire suppression indicates that understanding the physical properties of agents like Halocarbons is key for correct system sizing. As the temperature rises, the gas expands more readily, thus requiring adjustments in the amount needed for effective coverage.
NEW QUESTION # 55
A data center requires an audit to find out whether it conforms with ANSI/TIA-942 Rated-3 (concurrently maintainable).
Will the network architecture be part of this audit?
- A. Yes, but only if the network administration does not comply with ANSI/TIA-606.
- B. No, as concurrently maintainable only applies to electrical and mechanical (power and cooling).
- C. No, only the type of cabling used will be audited.
- D. Yes, amongst other aspects, the network architecture should be Rated-3 compliant with the requirements of ANSI/TIA-942.
Answer: D
Explanation:
For a Rated-3 data center, network architecture is indeed a key component of the audit under ANSI/TIA-942.
This rating requires concurrent maintainability across all systems, including telecommunications infrastructure. The network architecture must therefore meet specific redundancy and reliability standards to ensure uninterrupted operations during maintenance or failure of any single component.
Detailed Explanation:
Rated-3 requirements extend beyond electrical and mechanical systems to include network architecture. This ensures that telecommunications systems are also designed for concurrent maintainability, thus contributing to overall uptime and resilience.
EPI Data Center Specialist References:
EPI endorses comprehensive assessments for Rated-3 facilities, emphasizing that network systems must meet standards for redundancy and concurrent maintainability, which align with ANSI/TIA-942's holistic approach to data center reliability.
NEW QUESTION # 56
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?
- A. Install bus bar trunking
- B. Install three-phase power cabling based on three individual core wires
- C. Install three-phase power cabling based on a combined cable (e.g. XLPE etc.)
- D. Install single-phase power cabling
Answer: C
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 Explanation:
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 References:
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.
NEW QUESTION # 57
What is the redundancy setup shown in the diagram?
- A. 2(N+1)
- B. N+N+N
- C. 2+N+1
- D. N+2
Answer: D
Explanation:
The diagram shows three UPS modules, each 100 kW, connected in parallel to support a 100 kW IT load.
That means:
* One module (100 kW) can support the load (N).
* Two additional modules are installed as redundancy.
This equals N+2 redundancy.
* 2+N+1 and 2(N+1) imply dual active paths not shown.
* N+N+N is not an industry term.
Thus, the correct redundancy level is N+2.
References: ANSI/TIA-942-B §6.2 (UPS Redundancy Models), IEC 62040-3.
NEW QUESTION # 58
The building requires sprinklers and is equipped with a wet-pipe system. What action should you recommend for the computer room?
- A. Maintain the current wet-pipe system
- B. Replace the wet-pipe system with a deluge system
- C. Replace the wet-pipe system with a dry-pipe system
- D. Replace the wet-pipe system with a pre-action system
Answer: D
Explanation:
NFPA 75 (IT equipment rooms) recommends pre-action sprinklers for data processing spaces to minimize accidental water discharge risk; wet-pipe is generally discouraged directly over IT hardware.
References: NFPA 75 §5.4 (Water-based fire protection), NFPA 13 (sprinkler system types).
NEW QUESTION # 59
When designing a data center network, your company wants to minimize the number of network switches to manage.
What type of physical cabling layout would be the best choice?
- A. ToR (Top of Rack) design
- B. It does not matter as the number of switches is not influenced by the physical cabling layout
- C. Star network design using coaxial cables
- D. EoR (End of Row) design
Answer: D
Explanation:
An End of Row (EoR) design minimizes the number of network switches, as multiple racks can share a single switch at the end of a row, reducing switch counts and simplifying management. This design centralizes network switching to fewer points, which reduces the complexity and number of switches required compared to a Top of Rack (ToR) design, where each rack typically has its own switch.
Detailed Explanation:
In EoR designs, each row has a single network switch that handles the connections for all racks within that row. This reduces the number of individual switches needed and centralizes network management, which is ideal for minimizing equipment and simplifying infrastructure in the data center.
EPI Data Center Specialist References:
EPI promotes the EoR design as a way to reduce switch counts and streamline management in data centers.
This configuration allows for easier scaling and maintenance while maintaining efficient network connectivity.
NEW QUESTION # 60
What precaution shall be taken for cabling leading into an equipment rack when a data center is in a seismic- prone area?
- A. Cables shall be tightly organized to the rack and trays to avoid movement.
- B. Cables should be loosely organized to allow for movement and be latched at the connectors.
- C. Cables can be organized in any way as it is not important.
- D. Cables should be replaced by busbar trunking.
Answer: A
Explanation:
In seismic-prone areas, cables should be tightly secured to racks and cable trays to minimize movement during seismic activity. Properly securing the cables prevents them from being damaged due to excessive motion, which could lead to outages or damage to connected equipment.
Detailed Explanation:
Loose cables can be vulnerable to shaking or sudden jolts during an earthquake, increasing the risk of disconnection or damage. By tightly organizing and securing cables, you ensure they remain in place, even during significant movement, thereby maintaining connection integrity and reducing the risk of physical damage.
EPI Data Center Specialist References:
EPI training includes considerations for data centers in seismic zones, advising that cables be firmly anchored to support structures to reduce movement and mitigate potential damage during seismic events.
NEW QUESTION # 61
An MCB needs to be installed in the PDU of an ICT rack. Which breaking curve should you select?
- A. D-Curve
- B. C-Curve
- C. B-Curve
- D. A-Curve
Answer: B
Explanation:
MCBs (Miniature Circuit Breakers) are characterized by their tripping curves:
* B-Curve: Trips at 3-5 × rated current; suitable for resistive loads.
* C-Curve: Trips at 5-10 × rated current; suitable for mixed loads including ICT equipment with moderate inrush current.
* D-Curve: Trips at 10-20 × rated current; used for heavy inductive loads like motors.
* A-Curve: Very sensitive, rarely used outside specialty electronics.
Since ICT equipment like servers and network devices have moderate inrush currents (from power supplies), the recommended breaker is C-Curve. It balances protection against nuisance tripping while still ensuring fault clearance.
References: IEC 60898-1 (Circuit Breakers for Overcurrent Protection), IEC 60947-2 (LV Breakers), EXIN DCS study material: Electrical Distribution.
NEW QUESTION # 62
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