実践サンプルと問題集と指導には2025年最新のCDCS有効なテスト問題集
最新 [2025年07月10日] 100%合格率保証付きの素晴らしいCDCS試験問題PDF
質問 # 27
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. One feed from one substation split over two separated distribution boards in separate rooms
- B. Two feeds coming from two different substations, one power company is not acceptable
- C. Two feeds entering the data center building from one substation
- D. Two feeds coming from two different substations, one power company is acceptable
正解：D
解説：
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.
質問 # 28
Smoke sensors need to be tested to ensure that they pick up a potential fire in the data center.
What should you recommend?
- A. Inject smoke at the floor level
- B. Test the sensors according to the vendor specification
- C. Press the self-test button on each sensor in the data center
- D. Test the sensors by injecting smoke or simulated smoke directly into the sensor
正解：B
解説：
Testing smoke sensors should be conducted according to the vendor specifications to ensure compliance with safety standards and accurate results. Vendors provide specific testing procedures to account for the sensor type, environment, and operational characteristics, ensuring that tests do not damage the equipment or provide false results.
Detailed Explanation:
Smoke sensors can vary by type and sensitivity, so following the vendor's recommended testing procedure ensures the sensors function correctly without risking sensor damage. Injecting smoke or using a self-test might be insufficient or could lead to inaccurate assessments if they do not align with the vendor's testing protocol.
EPI Data Center Specialist References:
EPI recommends adhering to manufacturer specifications for testing critical safety equipment, ensuring that tests reflect real-world conditions without compromising sensor integrity or reliability.
質問 # 29
What is the advantage or disadvantage of using MPO (Multi-fiber Push On)/pre-terminated fiber?
- A. It is a very flexible system as it can be used for both copper cables and optical fiber cables.
- B. It speeds up installation and provides an easy upgrade to transmission speeds up to 40 Gbit/s -100 Gbit/s.
- C. There is no advantage, as it cannot be used with OM4 optical fiber cables.
- D. There is no advantage, as it creates additional heat load in the data center.
正解：B
解説：
MPO (Multi-fiber Push On) pre-terminated fiber offers the advantage of quick installation and supports high-speed upgrades up to 40 Gbit/s and 100 Gbit/s. This technology simplifies connections by allowing multiple fibers to be connected in a single plug-and-play module, reducing installation time and making future expansions or upgrades to higher speeds easier.
Detailed Explanation:
MPO connectors consolidate multiple fiber connections into a single interface, which simplifies cable management and reduces installation complexity. This setup is particularly beneficial in data centers where high-speed networks are essential, and where rapid deployment is necessary. MPO pre-terminated fiber also supports the use of OM4 fiber, making it compatible with existing high-performance cabling infrastructure.
EPI Data Center Specialist References:
EPI training highlights that pre-terminated fiber solutions, like MPO, can greatly enhance efficiency in data centers. By reducing installation time and providing scalability for higher transmission speeds, they align with best practices for maintaining flexible and future-ready network infrastructure.
質問 # 30
What mainly affects the cooling capacity of a raised floor tile?
- A. Percentage of the surface opening, obstruction of the supporting construction, pressure under the raised floor, damper construction
- B. Relative humidity in the computer room, temperature of the cold air, pressure under the raised floor, construction material of the tile
- C. Percentage of the surface opening, airflow direction of the ICT equipment, temperature difference between the air intake and air exhaust of the ICT equipment, construction material of the tile
- D. Type of ICT equipment, location of the air conditioner, pressure under the raised floor, allowable temperature in the hot aisle
正解：A
解説：
The cooling capacity of a raised floor tile is primarily influenced by the percentage of surface opening, the obstruction caused by the supporting construction, the pressure under the raised floor, and the damper construction. These factors dictate how much airflow can pass through the tile and how effectively cool air is distributed to the equipment in the data center.
Detailed Explanation:
The percentage of surface opening on a floor tile affects how much air can flow through, with larger openings allowing more airflow. Supporting structures beneath the floor can obstruct airflow, reducing cooling efficiency. Pressure under the raised floor impacts the velocity and volume of air that moves through the tile. Additionally, if dampers are installed, they control the airflow rate, which can be adjusted to meet specific cooling needs for the area.
EPI Data Center Specialist References:
EPI guidance on airflow management under raised floors emphasizes these factors as critical for effective cooling, especially in high-density areas. Ensuring unobstructed and adequate airflow helps maintain consistent cooling across equipment.
質問 # 31
What should be considered when installing overhead data cabling?
- A. 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.
- B. Copper data cabling should not be placed in metal cable trays.
- C. To maintain minimum separation from power and ensure that the fire detection and suppression systems are not hindered.
- 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.
正解：C
解説：
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.
質問 # 32
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?
- A. The cleaning crew is not doing their work properly
- B. Every computer room has high dust levels due to constant high-speed air movement
- C. Floorboards are most likely not fitted correctly
- D. Low pressure in the computer room
正解：C
解説：
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.
質問 # 33
The 'maximum exposed area' of the fire-rated glass is defined by the supplier as 3 sqm/32 sqft. The window area is 4 sqm/43 sqft.
What would be the best option?
- A. Do not use fire-rated glass due to the size limit and replace it with normal glass.
- B. Split the window into parts smaller than specified as the maximum exposed area and ensure fire-rated frames are used.
- C. Split the window in two equal parts using an aluminum frame.
- D. Split the window in two equal parts fitted together with transparent silicon glue.
正解：B
解説：
When the window area exceeds the maximum exposed area specified for fire-rated glass, it is necessary to split the window into sections that comply with the fire rating requirements. This means creating smaller sections that are each within the 3 sqm/32 sqft limit and using fire-rated frames to ensure that the entire assembly meets fire safety standards. This approach maintains the fire-rated integrity of the glass, while allowing for larger window areas.
Detailed Explanation:
Fire-rated glass is designed to contain fire and prevent it from spreading. If the window exceeds the maximum exposed area defined by the supplier, the integrity of the fire-rated glass could be compromised. By dividing the window into compliant sections with fire-rated frames, you ensure that each pane performs as intended in the event of a fire. Fire-rated frames help maintain the fire resistance across the entire assembly, making this option the best for safety and compliance.
EPI Data Center Specialist References:
EPI recommends adhering strictly to fire safety standards, especially when using materials like fire-rated glass. The guidelines emphasize that modifications should always respect the manufacturer's specifications to ensure the system remains effective in containing and preventing the spread of fire.
質問 # 34
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. Rated-2 since that is the lowest rating received
- B. Rated-4 since electrical is more important than mechanical and architectural
- C. Rated-4 since that is the highest rating received
- D. Depends on the Rating scored in telecommunications
正解：A
解説：
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.
質問 # 35
In which stage of the data center life cycle does commissioning take place?
- A. Implement
- B. Retire
- C. Design
- D. Operate/optimize
正解：A
解説：
Commissioning occurs during the Implementation stage of the data center life cycle. This phase involves the final testing and verification of systems and equipment to ensure they meet design specifications and operational requirements before the data center goes live.
Detailed Explanation:
The Implement phase includes activities such as installation, configuration, and testing. Commissioning is a crucial step that validates the performance and reliability of all critical systems, including power, cooling, and network infrastructure, to ensure they operate as intended under various conditions. Proper commissioning helps identify and resolve any issues before the data center becomes fully operational.
EPI Data Center Specialist References:
EPI training emphasizes that commissioning is essential for verifying that the data center meets design and performance criteria, aligning with best practices in data center project management to minimize risks and ensure readiness for operation.
質問 # 36
The air intake of the mission-critical server at the top of the rack is measuring 25 °C/77 °F.
Is this acceptable?
- A. As long as it does not exceed the average server room temperature of 38 °C/100 °F
- B. Yes, this is allowed according to the standards and guidelines
- C. No, the temperature needs to be 20 °C/68 °F
- D. Depends on the ANSI/TIA-942 Rating the data center needs to comply with
正解：B
解説：
An air intake temperature of 25 °C (77 °F) at the top of the rack is acceptable according to data center standards and guidelines, such as those from ASHRAE. This temperature falls within the recommended range for inlet temperatures, which is typically between 18°C (64°F) and 27°C (81°F).
Detailed Explanation:
ASHRAE standards provide guidelines on acceptable temperature ranges for air intake in data centers to balance cooling efficiency and equipment safety. A temperature of 25°C is within the recommended operational range, allowing data centers to optimize energy efficiency while maintaining safe conditions for IT equipment.
EPI Data Center Specialist References:
EPI guidelines align with ASHRAE recommendations for server intake temperatures, confirming that 25°C is within acceptable limits for most mission-critical equipment. This ensures the data center maintains an efficient and reliable environment.
質問 # 37
You are installing new copper cabling.
What is the advantage or disadvantage of choosing pre-terminated category 6 or 6A cabling?
- A. There is no advantage as most new copper cabling network designs are based on category 3 or 5E for horizontal cabling.
- B. Pre-terminated cabling has a higher fire rating.
- C. Pre-terminated cabling makes ordering of the copper cables more complex, as you need to know in advance on which side the male or female connector needs to be located.
- D. Pre-terminated cabling is already factory tested and saves installation time.
正解：D
解説：
Choosing pre-terminated category 6 or 6A cabling provides several advantages, primarily related to time savings and reliability. Since pre-terminated cables are factory tested, they ensure consistent quality and performance, reducing the need for additional testing during installation. This makes installation faster and more efficient, which can significantly reduce labor costs and deployment times.
Detailed Explanation:
Pre-terminated cabling systems are manufactured and tested in controlled environments, which ensures they meet industry standards for performance. This factory testing process minimizes the likelihood of faults, reducing the need for troubleshooting and retesting on-site. Moreover, pre-terminated solutions can help to streamline installations because they eliminate the need for on-site terminations, which can be time-consuming and require skilled labor.
This is especially beneficial for data centers, where rapid deployment and minimizing potential points of failure are critical to maintaining uptime. However, it is important to note that pre-terminated cables require accurate planning, as lengths and connector configurations must be predetermined.
EPI Data Center Specialist References:
According to EPI Data Center Specialist guidelines, pre-terminated cabling is advantageous in data center environments due to reduced installation time and enhanced reliability from factory testing. These attributes align with best practices for efficient data center management, where maintaining performance and minimizing downtime are priorities.
質問 # 38
What indicates the breaking capacity of a fuse or breaker?
- A. Mechanical strength of the casing of a fuse or breaker.
- B. The maximum voltage, in case of an electrical surge, that the fuse or breaker can handle without being destroyed or causing an electric damaging arc.
- C. The current that a fuse or breaker is able to interrupt without being destroyed or causing an electric damaging arc.
- D. The current at which the device will trip.
正解：C
解説：
The breaking capacity of a fuse or breaker indicates the maximum current it can safely interrupt without being damaged or creating a dangerous arc. This value is crucial for ensuring that the device can handle fault conditions and prevent equipment damage or fire risks due to excessive current flow.
Detailed Explanation:
The breaking capacity, also known as the interrupting rating, ensures that the fuse or breaker can safely handle fault currents up to a specified limit. Exceeding this capacity could result in the device failing to interrupt the current, potentially causing hazardous conditions like electrical arcs.
EPI Data Center Specialist References:
EPI training underscores the importance of matching fuses and breakers with appropriate breaking capacities for the anticipated fault levels in data centers to ensure reliable and safe operation.
質問 # 39
An air-conditioner unit needs to be selected. Two types are available:
Unit-A has a Sensible Heat Ratio (SHR) of 0.7.
Unit-B has a Sensible Heat Ratio (SHR) of 0.9.
From an efficiency point of view, which one should be selected?
- A. Unit B
- B. Unit A
- C. Not relevant, as Sensible Heat Ratio is only specified for air-conditioner equipment to indicate the ratio between intake temperature and exhaust temperature.
- D. It does not matter, as the Sensible Heat Ratio has nothing to do with efficiency.
正解：A
解説：
From an efficiency standpoint, Unit B with a Sensible Heat Ratio (SHR) of 0.9 is preferable. A higher SHR indicates that a greater proportion of the air conditioner's capacity is dedicated to sensible cooling (temperature reduction) rather than latent cooling (moisture removal). In data centers, sensible cooling is more critical since IT equipment primarily generates heat without adding significant moisture.
Detailed Explanation:
An SHR of 0.9 means that 90% of the cooling capacity is used for sensible cooling, which is more efficient for environments like data centers where humidity control is typically less of a concern. Opting for an air conditioner with a higher SHR ensures that most of the cooling energy is focused on temperature reduction, making Unit B more efficient in this scenario.
EPI Data Center Specialist References:
EPI data center best practices recommend choosing cooling units with higher SHR values in data centers, as they better match the cooling needs of IT equipment. High SHR units improve cooling efficiency by concentrating on sensible heat removal, which is vital for maintaining the optimal thermal environment.
質問 # 40
Is it allowed to make design changes during the implementation phase?
- A. Only when there is a strong business and/or technical justification.
- B. No, after a design freeze no further changes are allowed.
- C. Yes, but only when time to implement is not exceeded.
- D. Any change is fine as long as it is within the scope of the project.
正解：A
解説：
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.
質問 # 41
Which formula is correct?
- A. Phase-to-Neutral Voltage = (Phase-to-Phase voltage * 1.732) / Phase-to-Neutral Voltage
- B. Phase-to-Neutral Voltage = Phase-to-Phase voltage /1.732
- C. Phase-to-Neutral Voltage = Phase-to-Neutral voltage * 1.732
- D. Phase-to-Neutral Voltage = Phase-to-Phase voltage * 1.732
正解：B
解説：
The correct formula for calculating Phase-to-Neutral Voltage in a three-phase power system is Phase-to-Neutral Voltage = Phase-to-Phase Voltage / 1.732. This formula applies to balanced three-phase systems, where 1.732 (or √3) represents the relationship between line-to-line and line-to-neutral voltages.
Detailed Explanation:
In three-phase systems, Phase-to-Phase Voltage is higher than Phase-to-Neutral Voltage by a factor of √3. Dividing the phase-to-phase voltage by 1.732 gives the phase-to-neutral voltage, which is critical for understanding power distribution in three-phase electrical systems commonly found in data centers.
EPI Data Center Specialist References:
EPI electrical training highlights the importance of knowing these calculations for designing and maintaining balanced power systems, which are essential for stable and efficient data center operations.
質問 # 42
You are working with a customer who requires a guarantee that THDi levels coming from the UPS should not exceed more than 3% THDi. Furthermore, he wants to run a power-efficient data center. The UPS has a 6-Pulse SCR/Thyristor based rectifier. The current load on the UPS is approximately 80%. The customer indicates they are not expecting any changes on the ICT infrastructure for the next 3 years.
What should you recommend?
- A. Nothing, the UPS will be able to take care of the right levels of THDi
- B. Install a passive harmonic filter on the UPS
- C. Install an isolation transformer rated at K13 or K20
- D. Install an active harmonic filter on the UPS
正解：D
解説：
Given the customer's requirement to limit Total Harmonic Distortion (THDi) to below 3% and the presence of a 6-pulse SCR/Thyristor-based rectifier, an active harmonic filter is the best solution. A 6-pulse rectifier typically generates higher harmonic distortion, often exceeding 3%, especially under substantial loads like 80%. An active harmonic filter dynamically monitors and compensates for harmonic distortion, effectively reducing THDi and supporting a more power-efficient operation, aligning with the customer's energy efficiency goals.
Detailed Explanation:
Passive harmonic filters can reduce harmonics but are less effective at maintaining low THDi levels under varying loads. Active filters offer real-time correction and can achieve lower THDi levels than passive filters, especially in systems with fluctuating loads or where strict harmonic limits are required. Installing an active harmonic filter will ensure compliance with the specified THDi limits and optimize power quality.
EPI Data Center Specialist References:
EPI guidance on power quality management recommends active harmonic filters for environments where strict THDi levels are necessary. Active filters offer better control over harmonic levels, supporting both compliance and operational efficiency.
質問 # 43
What is the main disadvantage of using a ToR (Top of Rack) design?
- A. There will be more switches to manage.
- B. A single ToR (Top of Rack) switch is more expensive than an EoR (End of Row) switch.
- C. You need a separate rack to install all your ToR (Top of Rack) switches.
- D. A ToR (Top of Rack) switch has only optical interfaces.
正解：A
解説：
A Top of Rack (ToR) design typically requires more switches because each rack has its own switch to manage network connections, as opposed to End of Row (EoR) or centralized designs, which consolidate switches. While ToR designs improve cabling efficiency and reduce latency, they also increase the number of switches, thus raising management complexity and potentially increasing capital and operational costs.
Detailed Explanation:
In a ToR setup, each rack's individual switch allows for quick access and streamlined cabling within the rack. However, this setup means more devices to configure, monitor, and maintain, which can increase administrative overhead and network management complexity.
EPI Data Center Specialist References:
EPI documentation notes that ToR designs can improve performance but also lead to increased management needs due to the higher switch count, making them less ideal in environments where simplified network management is prioritized.
質問 # 44
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?
- A. No, as long as the equipment is less than 700 kg/1,500 lbs it will be within the limits.
- B. Yes, additional floor loading calculations need to be done by the floor manager, which should be verified by the safety engineer.
- C. 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.
- D. Yes, a structural engineer, approved/endorsed by the building owner, should carry out new floor loading calculations.
正解：D
解説：
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 Explanation:
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 References:
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.
質問 # 45
Management has requested a 15-minute battery bank assuming full load on the UPS. The UPS vendor has provided the following specifications of the UPS:
* Rated power: 30 kVA
* Rectifier input voltage: 400 V/3 phase
* Rectifier input power factor: 0.8
* Battery rated voltage: 384 V
* Number of cells: 192
* End of discharge voltage: 308 V
* Inverter output voltage: 400 V/3 phase
* Inverter output power factor: 0.8
What information is missing to perform the battery calculation?
- A. Inverter efficiency
- B. Available battery charging current
- C. Load imbalance on the phases
- D. UPS efficiency
正解：D
解説：
To determine the required capacity of the battery bank for the 15-minute runtime at full load, one must know the total power requirement that the battery bank must supply. The specifications provided include most of the necessary details, such as rated power, input voltage, battery voltage, and discharge voltage. However, one critical piece of information is missing: the UPS efficiency.
Detailed Explanation:
In a data center UPS system, the battery bank is designed to supply power for a set duration when there is an input power failure. The UPS efficiency affects the actual power the UPS can deliver to the load compared to the power it draws from the batteries. The efficiency factor is necessary to accurately calculate the required capacity of the battery bank since it determines how much input power is needed from the batteries to supply the load at full capacity. The formula typically used to determine battery capacity involves factoring in UPS efficiency, as it allows you to understand the losses within the UPS system.
If UPS efficiency is not considered, there would be an inaccurate estimation of the actual power needed from the batteries. For instance, if a UPS has 90% efficiency, only 90% of the power drawn from the batteries reaches the load. Without knowing this efficiency, it is not possible to calculate the battery bank size accurately, as you cannot accurately estimate the losses within the UPS itself.
EPI Data Center Specialist References:
According to EPI Data Center Specialist training, understanding the UPS efficiency is essential for battery sizing. Without it, the calculations could lead to either undersizing or oversizing the battery bank, which affects both reliability and cost-effectiveness of the UPS system. The EPI Data Center Specialist course emphasizes that battery sizing must account for all losses within the UPS system, with efficiency being a primary factor in these calculations.
質問 # 46
What is a potential disadvantage of using a hypoxic-based fire suppression system as a fire extinguishing system?
- A. It can only be used in computer rooms which have sufficient air changes per hour.
- B. The gas containers need to be close to the hazard area.
- C. It can only be used in computer rooms where you have sufficient positive pressure.
- D. It can only be used in non-continuous occupied areas.
正解：D
解説：
A hypoxic-based fire suppression system works by reducing the oxygen level in a room to below what is necessary to sustain combustion. This makes it effective in fire prevention, but it is not suitable for continuous occupancy by personnel. Low oxygen levels can cause discomfort or even health risks for people spending extended periods in the space. Therefore, these systems are typically deployed in areas where continuous human occupancy is not required, such as storage rooms or data halls with limited personnel access.
Detailed Explanation:
Hypoxic fire suppression systems lower oxygen levels to around 15-16%, which is safe for short periods but not sustainable for continuous occupancy without risk to health. Data center environments where staff need to spend long periods monitoring and maintaining equipment would need alternative systems, like gas-based suppression that allows for safe evacuation rather than oxygen reduction.
EPI Data Center Specialist References:
The EPI Data Center Specialist curriculum emphasizes that fire suppression systems must be chosen based on occupancy requirements. Hypoxic systems are specifically noted as unsuitable for spaces requiring continuous human presence due to the low oxygen environment they create.
質問 # 47
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?
- A. Yes, as long as you take the difference between the net and gross volume into account.
- B. Yes, as long as you use the same units of measure, i.e., kg/m³ or lbs/ft³.
- C. No, there is a significant difference in the formula for the different types of fire suppression gases.
- D. Yes, as long as you change the 'S' factor of the formula to reflect the gas type used.
正解：C
解説：
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.
質問 # 48
The humidity in the computer room has changed from about 50% down to 35% Relative Humidity (RH).
What influence does this have on Electrostatic Discharge (ESD)?
- A. ESD levels will go down
- B. No influence as long as the temperature is at approximately 20°C/77°F
- C. ESD levels will go up
- D. Relative humidity has no influence on ESD
正解：C
解説：
As relative humidity decreases, Electrostatic Discharge (ESD) risks increase. Lower humidity levels reduce the amount of moisture in the air, which normally helps dissipate static charges. When the humidity drops from 50% to 35%, the likelihood of static electricity accumulating on surfaces rises, leading to a higher potential for ESD incidents that could damage sensitive IT equipment.
Detailed Explanation:
ESD events are more common in dry environments because there is less atmospheric moisture to neutralize electrical charges. Maintaining relative humidity above 40% helps minimize the risk of ESD, which is why data centers often control humidity levels tightly to protect equipment from static discharge that could cause hardware failures or data loss.
EPI Data Center Specialist References:
EPI data center best practices stress the importance of maintaining stable humidity levels to prevent ESD, particularly in computer rooms. Recommended humidity ranges are typically above 40% to prevent conditions that would foster static buildup.
質問 # 49
The logical overview of the data center looks as pictured. To what TIA-942 Rating is this design made based on electrical only?
- A. Rating - 4
- B. Rating - 2
- C. Rating - 3
- D. Rating - 1
正解：A
解説：
The electrical design shown in the diagrams represents a TIA-942 Rating-4 configuration. This design includes full redundancy and fault tolerance, as demonstrated by the dual power distribution paths from the utility supply to the critical loads. Each power distribution path is equipped with its own UPS, ensuring that the ICT equipment and mechanical equipment have uninterrupted power in case of any single point of failure.
Detailed Explanation:
A Rating-4 data center requires two independent power paths that are fully redundant and capable of supporting the load independently. In the diagrams:
There are dual feeds from the utility supply, each going through separate transfer switches and power distribution paths.
Both paths have backup sources (+1) and serve critical components through separate UPS systems, providing a completely redundant setup.
The design also includes redundant paths to the mechanical equipment and ICT equipment, which further indicates the fault-tolerant characteristics of a Rating-4 infrastructure.
This setup allows for concurrent maintainability and ensures that no single failure in power distribution or UPS can impact the data center's operation, which is characteristic of the highest Tier/Rated-4 classification.
EPI Data Center Specialist References:
EPI guidelines confirm that TIA-942 Rating-4 requires full redundancy and fault tolerance for electrical infrastructure, ensuring continuous operation even during maintenance or failure events. This design meets all those requirements, thus aligning with Rating-4 standards.
質問 # 50
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. As close as possible to the computer room
- B. 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
- C. Shielding is not required to be installed as 100mG is within the acceptable levels for computer rooms
- D. As close as possible to the transformer room
正解：D
解説：
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.
質問 # 51
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EXIN CDCS 認定試験の出題範囲：
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