[2026年03月23日] CDCPのPDF問題集にはあなたに不可欠なCDCP試験解答を合格に繋ぐ！ [Q11-Q33]

According to the EPI Data Centre Training Framework, EMF is a form of electromagnetic interference (EMI) that can disrupt or damage the normal operation of electronic devices, such as servers, network cables, and IT equipment1. High levels of EMF can be generated by power equipment, cell phones, microwaves, TV and radio signals, etc., and can cause data corruption, data loss, system malfunction, and crashes23. Therefore, EMF can cause data centre failures and affect the availability, performance, and security of the data centre. To prevent or mitigate EMF, data centres should follow the best practices for data centre design, layout, cabling, grounding, shielding, and testing14.
References: 1: EPI Data Centre Training Framework, Module 5: Power, Section 5.4.1: Electromagnetic Interference, Page 5-34 2: EMI in the Data Center: To Shield Or Not ToShield2 3: Electromagnetic Interference in Data Centers: Risks Involved and Its Impact on Information Security4 4: Data Center Electromagnetic Interference and Tier Standards1

Glass door racks are a type of rack that have solid glass front doors and rear door heat exchangers (RDHx).
RDHx are devices that use facility coolant to absorb heat from the exhaust air of the IT equipment and return cool air to the room. RDHx can be either passive or active, depending on the fan configuration. In general, IT hardware within the rack is air-cooled and the door heat exchanger uses facility coolant to absorb heat from exhaust air to return air to the facility at or near inlet air temperature to the rack. This rear door heat exchanger can either be a passive or active solution. When dealing with glass door racks, cool air is injected into the rack from the rear door in a downflow direction. This means that the cool air flows from the top to the bottom of the rack, following the natural convection of the hot air rising. This way, the cool air can reach all the IT equipment in the rack and prevent hot spots or overheating.
References: [SOLVED] Rack – Solid or Mesh front door? – Data Center
IT](https://community.spiceworks.com/topic/510677-rack-solid-or-mesh-front-door), ChilledDoor, Rear Door Heat Exchanger | Data Center Cooling, ACS Door Heat Exchanger Requirements for Open Rack.

MTBF stands for Mean Time Between Failures, and it is the arithmetic mean of time between the failing and the subsequent running of the system in a particular time period. MTBF is a measure of reliability that indicates how often a system or component fails during its operation. MTBF can be calculated by dividing the total operating time by the number of failures over a given period. For example, if a system operates for 1000 hours and experiences 5 failures, the MTBF is 1000/5 = 200 hours.
References: EPI Data Centre Training Framework, CDCP Preparation Guide, MTBF, MTTR, MTTF, MTTA:
Understanding incident metrics – Atlassian

According to the EPI Data Centre Operations Standard (DCOS), exit/emergency signs should be located at every escape door and pathways leading to doors (arrows) to ensure a safe and quick evacuation in case of an emergency1. This is also consistent with the best practices for data centre emergency preparedness and response, which recommend having a clear and visible signage system for emergency exits23.
References: 1: EPI Data Centre Operations Standard (DCOS), Version 2.0, Section 5.4.2.1, Page 42 2: How to Prepare and Respond to Data Center Emergencies, White Paper 217, Schneider Electric, Page 4 3: How to Properly Manage Data Center Emergencies, IT Business Edge, Slide 2

According to the IEEE definition, reliability is the ability of a system or component to perform its required functions under stated conditions for a specified period of time. Reliability is a measure of how often a system or component fails, and how long it takes to recover from a failure. Reliability is closely related to availability, which is the degree to which a system or component is operational and accessible when required for use.
Reliability and availability are both affected by factors such as design, maintenance, testing, and environmental conditions.
References: EPI Data Centre Training Framework, CDCP Preparation Guide, Reliability engineering – Wikipedia

A computer room air handling unit (CRAH) is a device that uses circulating chilled water to remove heat from the data center environment. A CRAH consists of a fan, a coil, and a filter. The fan draws the warm air from the data center and passes it through the coil, where the heat is transferred to the chilled water. The chilled water is supplied by a chiller or a cooling tower, and the cooled air is returned to the data center. A CRAH is different from a computer room air conditioning unit (CRAC), which uses a refrigerant instead of chilled water to cool the air.
References:
*EPI Data Centre Professional (CDCP) Preparation Guide, page 36
*Chilled Water Systems: Applications and Common Uses
*The Principles of Basic Refrigeration: What is a chiller?

A physical infrastructure in a Data Center consists of racks, which are metal frames used to store and organize server and other IT equipment. The racks are usually arranged in rows and columns, and they can be used to hold servers, storage devices, and other pieces of IT equipment. The racks can also be used to organize cables and other components to ensure that the Data Center is kept organized and efficient.

According to the CDCP Preparation Guide, an audible signaling and notification device is a device that produces a sound to alert or notify the occupants of a data center of an event or condition. Sirens are examples of such devices, as they can emit loud and distinctive tones to warn of fire, emergency, or security incidents.
Strobes, on the other hand, are visual signaling and notification devices that produce flashes of light to attract attention or convey information. Alarms and clocks are not specific types of devices, but rather general terms that can refer to various audible or visual devices.
References: CDCP Preparation Guide, page 30. Audible Visual Notification | System Sensor | Honeywell.
Audible-Visual Signaling Devices – AutomationDirect.

Water sprinkler systems are designed to protect the structure of a building from fire by suppressing or extinguishing the flames with water. Water sprinkler systems are typically installed in the ceiling or walls of a building and are activated by heat or smoke detectors. Water sprinkler systems can reduce the risk of fire spreading and causing structural damage to the building.
References:
*EPI Data Centre Professional (CDCP) Preparation Guide, page 28
*Fire Protection Systems for Data Centers | EPI

Single-mode cabling and multi-mode cabling are two types of fiber optic cables that differ in their core diameter, wavelength, light source, bandwidth, distance, and cost. Single-mode cabling has a smaller core diameter and uses a laser as a light source, which enables it to transmit data over longer distances and higher bandwidths. However, single-mode cabling is also more expensive than multi-mode cabling, because it requires more precise alignmentand splicing, and more costly light sources and connectors. Multi-mode cabling has a larger core diameter and uses LEDs or VCSELs as a light source, which makes it cheaper and easier to install and maintain. However, multi-mode cabling also has a shorter distance and lower bandwidth than single-mode cabling, because it suffers from more modal dispersion and attenuation.
References:
1: Data Center Cabling: Single Mode vs Multimode Fibers2, page 1, section 1 3: Single Mode vs Multimode Fiber Cable Guide4, page 1, section 1 5: Single-Mode vs. Multi-Mode Fiber Cables: Explained6, page 1, section 1 7: 2 Types of Fiber Optic Cable: Single Mode vs. Multimode Fiber8, page 1, section 1

According to the CDCP Preparation Guide1, magnetic fields of the type ‘H’ or ‘B’ are created when an electric current flows through a conductor, such as a wire or a coil. The magnetic field strength ‘H’ is proportional to the current ‘I’ and the number of turns ‘N’ of the coil, and inversely proportional to the length
‘l’ of the coil. The magnetic flux density ‘B’ is proportional to the magnetic field strength ‘H’ and the permeability ” of the medium in which the magnetic field exists. The greater the current, the stronger the magnetic field and the magnetic flux density. The relationship between ‘H’, ‘B’, ‘I’, ‘N’, ‘l’, and ” can be expressed by the following equations:
H = N I / l
B =H
References:
1: CDCP Preparation Guide, page 23, section 2.4.2.1 2: Difference between B and H in magnetic fields?3, page 1, section 1 4: Magnetic field | Definition & Facts5, page 1, section 1

Data centre design and infrastructure standards can vary from country to country, depending on the local regulations, codes, and practices. Therefore, it is important to check the local standards before designing, building, or operating a data centre in a specific location. Compliance to only international standards may not be sufficient or adequate to meet the local requirements, which could result in legal, financial, or operational risks. For example, some countries may have stricter fire safety, environmental, or energy efficiency standards than the international ones. Some countries may also have different electrical standards, such as voltage, frequency, or plug types. By checking the local standards, you can ensure that your data centre is compliant, safe, and efficient in the local context.
References:
1: Data Center Design: Which Standards to Follow?2, page 1, section 1 3: The Most Important Data Center Design and Infrastructure Codes and Standards4, page 1, section 1 5: Explaining the new family of ISO Data Centre Standards6, page 1, section 1 7: Standards for data centre certification. Is a changing coming?8, page 1, section 1

According to the CDCP Preparation Guide, smoke detectors are the most common type of fire detection devices used in data centers, as they can detect a fire in its early stages and provide early warning to the occupants and authorities. Smoke detectors can be either spot-type or air-aspirating, depending on the design and goals of the data center. Spot-type detectors are inexpensive and simple, but may cause activation delay and false alarms. Air-aspirating detectors are more sensitive and reliable, but may require more maintenance and installation costs. Both types of detectors should be installed in accordance with the relevant standards and codes, such as NFPA 72 and EN 54.
References: CDCP Preparation Guide, page 30-31. Evaluating Fire Detection Options For Data Centers.
Fire Detection and Suppression Systems in a Data Center.

Shielded twisted pair cables (STP) are Ethernet cables that feature additional protection against electromagnetic interference from external sources, such as radio waves, microwaves, or other network cables.
This is achieved by wrapping each pair of wires with a conductive shield, usually made of foil or braided wire, and then enclosing the entire cable with another shield layer. However, this shielding is not effective against low frequency electromagnetic fields (EMF) from power cables, which can induce currents and voltages in the network cables and cause signal distortion or data loss. Low frequency EMF can only be reduced by increasing the distance between the power and network cables, or by using a tre-foil cable arrangement, which is a special configuration of three power cables twisted together to cancel out the magnetic fields they generate.
References: STP Cable: Your Shield Against Network Disturbances; What is Shielded Twisted Pair Cable? – Advantages, Disadvantages; Shielded vs. Unshielded Cables: What’s the Difference? – Cable Matters.

Data centre design and infrastructure standards can vary from country to country, depending on the local regulations, codes, and practices. Therefore, it is important to check the local standards before designing, building, or operating a data centre in a specific location. Compliance to only international standards may not be sufficient or adequate to meet the local requirements, which could result in legal, financial, or operational risks. For example, some countries may have stricter fire safety, environmental, or energy efficiency standards than the international ones. Some countries may also have different electrical standards, such as voltage, frequency, or plug types. By checking the local standards, you can ensure that your data centre is compliant, safe, and efficient in the local context.
References:
1: Data Center Design: Which Standards to Follow?2, page 1, section 1 3: The Most Important Data Center Design and Infrastructure Codes and Standards4, page 1, section 1 5: Explaining the new family of ISO Data Centre Standards6, page 1, section 1 7: Standards for data centre certification. Is a changing coming?8, page
1, section 1

According to the Raised Floor Installation Manual, the best practice for cutting holes in the raised floor tile is to draw a cross on the tile and when making a cut-out do not touch a line and avoid the corners1. This ensures that the structural integrity and load-bearing capacity of the tile are not compromised. Cutting holes anywhere, touching the line, or cutting the corners can weaken the tile and cause it to crack or collapse1.
Additionally, the manual recommends using a drill press or a reciprocating saw with a metal or bi-metal cutting blade, and deburring all sharp edges1.
References: 1: Raised Floor Installation Manual, E. Recommended Cutting Tools, Page 1

Infrared humidifiers are a type of humidifier that use quartz lamps to heat water in an open pool and evaporate it into the air. They are energy-intensive and require frequent maintenance and cleaning. They are not recommended for data centers, as they can introduce contaminants and bacteria into the air, and increase the risk of fire and electrical hazards.
References: EPI Data Centre Training Framework, CDCP Preparation Guide, Make Humidification Adjustments | ENERGY STAR

Availability is the degree to which a system, product or component is operational and accessible when required for use. It is one of the attributes of reliability, which is the ability of a system or component to perform its required functions under stated conditions for a specified period of time. Availability can be calculated as the ratio of the expected value of the uptime (the time when the system is functional) to the total time (uptime plus downtime) of a system or component. Availability can also be influenced by factors such as maintainability, fault tolerance, redundancy, diagnostics, and logistics.
References: EPI Data Centre Professional (CDCP) Preparation Guide, page 8; Availability – Wikipedia; Reliability – ISO 25000.

Busbar trunking systems are a method of power distribution using rigid copper or aluminium conductors to distribute the power around a building. Busbar trunking systems have many advantages over cables, such as lower space requirements, higher short-circuit strength, lower fire load, and easier installation. One of the main advantages of busbar trunking is that it allows for flexibility in terms of power transmission and distribution. Busbar trunking systems can be easily relocated, modified, or expanded to accommodate changes in the building layout or load demand. Busbar trunking systems can also be fitted with various components, such as tap-off units, elbows, tees, and end feed units, to provide power to different locations and consumers.
Busbar trunking systems can also be installed both overhead and under the raised floor, depending on the design and preference of the building.
References: Why I prefer busbar trunking systems more than cables | EEP, Why should you choose Busbar over Cable? – E+I Eng, Busbar VS Cables for Riser Applications – An Electrical Engineer.

According to the CDCP Preparation Guide, a natural disaster is a catastrophic event that is caused by natural forces and has a significant impact on human lives, property, and environment. Hurricanes are examples of natural disasters, as they are powerful storms that form over warm ocean waters and produce strong winds, heavy rain, storm surges, and flooding. Grid failure, blackouts, and human error are not natural disasters, but rather man-made or technological disasters that result from failures or errors in human systems or activities.
References: CDCP Preparation Guide, page 9. Natural Disaster Readiness for Data Centers. EM-DAT – The international disaster database. PDC Global – Pacific Disaster Center.

Busbar trunking systems are a method of power distribution using rigid copper or aluminium conductors to distribute the power around a building. Busbar trunking systems have many advantages over cables, such as lower space requirements, higher short-circuit strength, lower fire load, and easier installation. One of the main advantages of busbar trunking is that it allows for flexibility in terms of power transmission and distribution.
Busbar trunking systems can be easily relocated, modified, or expanded to accommodate changes in the building layout or load demand. Busbar trunking systems can also be fitted with various components, such as tap-off units, elbows, tees, and end feed units, to provide power to different locations and consumers. Busbar trunking systems can also be installed both overhead and under the raised floor, depending on the design and preference of the building.
References: Why I prefer busbar trunking systems more than cables | EEP, Why should you choose Busbar over Cable? – E+I Eng, Busbar VS Cables for Riser Applications – An Electrical Engineer.

Hot- or cold-aisle containment is a strategy to improve the cooling efficiency and reduce the energy consumption of data centers by isolating the hot exhaust air from the cold supply air. However, implementing this strategy in an existing computer room may create potential issues with the existing fire suppression system (s), such as:
*The containment barriers may interfere with the distribution and activation of the fire suppression agents, such as water, gas, or aerosol, and reduce their effectiveness in extinguishing a fire.
*The containment barriers may create pockets of high temperature and pressure that could damage the equipment or the containment structure itself in the event of a fire.
*The containment barriers may obstruct the access and visibility of the fire detection and alarm devices, such as smoke detectors, heat sensors, or manual call points, and delay the response time of the fire suppression system(s).
*The containment barriers may violate the local fire codes and regulations that specify the minimum clearance and ventilation requirements for the data center.
Therefore, when implementing hot- or cold-aisle containment in an existing computer room, it is important to consider the impact on the existing fire suppression system(s) and take appropriate measures to ensure the safety and compliance of the data center, such as:
*Consulting with the fire authorities and the fire suppression system vendor to assess the compatibility and suitability of the containment solution with the existing fire suppression system(s).
*Modifying or upgrading the existing fire suppression system(s) to accommodate the containment solution, such as relocating or adding fire suppression devices, adjusting the discharge rate and pressure, or installing a secondary fire suppression system within the contained area.
*Installing fire-rated containment barriers that can withstand high temperatures and resist the spread of fire and smoke, and that have self-closing or automatic release mechanisms in case of a fire.
*Installing fire detection and alarm devices within the contained area and ensuring their proper integration and communication with the existing fire suppression system(s).
*Conducting regular testing and maintenance of the fire suppression system(s) and the containment solution to ensure their functionality and reliability.
References: EPI Data Centre Framework, Module 4: Fire Protection, page 10-11. EPI Data Centre Professional (CDCP) Reference Materials, page 66-67. 1, 2, 3.

According to the IEEE definition, reliability is the ability of a system or component to perform its required functions under stated conditions for a specified period of time. Reliability is a measure of how often a system or component fails, and how long it takes to recover from a failure. Reliability is closely related to availability, which is the degree to which a system or component is operational and accessible when required for use. Reliability and availability are both affected by factors such as design, maintenance, testing, and environmental conditions.
References: EPI Data Centre Training Framework, CDCP Preparation Guide, Reliability engineering – Wikipedia