CDCP Certified Data Centre Professional (CDCP) Questions and Answers

According to the CDCP® Preparation Guide, Class A fires involve ordinary combustible materials such as paper, wood and cloth. These materials leave behind ash or embers when they burn. Class A fires can be extinguished by water or other cooling agents that reduce the temperature of the fuel below its ignition point.

Direct air handlers are a type of cooling system that use outdoor air to cool the data centre. They draw in fresh air from outside, filter it, and supply it to the data centre at the desired temperature and humidity level. Direct air handlers can reduce the energy consumption and operating costs of data centres by eliminating the need for mechanical cooling or refrigeration. However, they also have some challenges and limitations that need to be considered. One of the main factors to consider when using direct air handlers for data centres is the temperature, humidity and contamination of the outdoor environment. Depending on the location and climate of the data centre, the outdoor air may not always be suitable for cooling the data centre. For example, if the outdoor air is too hot, too humid, or too polluted, it may not provide enough cooling capacity, or it may damage the IT equipment or cause corrosion. Therefore, direct air handlers need to have sensors and controls to monitor the outdoor air quality and adjust the airflow accordingly. They may also need to have backup cooling systems or supplementary cooling devices, such as evaporative coolers or heat exchangers, to cope with extreme weather conditions or peak loads.

The fire triangle is a simple model that illustrates the three elements that a fire needs to ignite and sustain: oxygen, heat, and fuel. Oxygen is the oxidizing agent that enables the combustion reaction, heat is the energy source that raises the temperature of the fuel to its ignition point, and fuel is the material that reacts with oxygen and releases heat and light. Removing any one of these elements can extinguish a fire. For example, water can reduce the heat and the oxygen, sand or soil can smother the fuel and the oxygen, and fire extinguishers can displace the oxygen or lower the temperature.

High relative humidity in a data center can lead to corrosion of metal parts and electronic contacts, potentially causing failures. Electrostatic discharge is a risk with low humidity, not high.

According to the EPI Data Centre Training Framework, lithium-ion batteries are becoming more popular in data centres due to their higher energy density, longer lifespan, and lower maintenance costs compared to lead-acid batteries1. However, lithium-ion batteries also have some drawbacks, such as higher initial cost, stricter safety requirements, and potential thermal runaway risks1. Therefore, a battery management system (BMS) is essential to monitor and control the voltage, current, temperature, and state of charge of each battery cell or module, and to prevent overcharging, over-discharging, or overheating23. A BMS can also communicate with the UPS system and provide information on the battery status, performance, and health2.

Physical separation is the most cost-effective method to minimize electromagnetic interference. Specialized shielding is more expensive and usually unnecessary if proper separation is maintained.

The type of copper wire that is used for grounding the racks to the SRG (signal reference grid) in a data centre is braided copper wire or flat copper strip, according to the CDCP Preparation Guide1 and various web sources234. Braided copper wire or flat copper strip are preferred over thin or thick copper cable for grounding purposes, because they have lower impedance and higher surface area, which allow better dissipation of electrical noise and interference. Moreover, braided copper wire or flat copper strip are more flexible and durable than copper cable, which make them easier to install and maintain. Braided copper wire or flat copper strip should be connected to the SRG using exothermic welding or other code-compliant methods, and should follow the relevant standards and codes, such as ANSI/TIA/EIA-607 and NFPA 70.

The UPS (uninterruptible power supply) is a device that provides backup power to the ICT equipment in case of a power outage or a power quality issue. The UPS should be dedicated to the ICT equipment only, and not to other loads, such as lighting, cooling, or security systems. This is because connecting fluorescent lights to the same UPS as the ICT equipment can cause several problems, such as:

•Reducing the battery runtime of the UPS, which may not be enough to support the ICT equipment until the backup generator kicks in or the utility power is restored.

•Increasing the harmonic distortion of the UPS output, which can affect the performance and reliability of the ICT equipment and the UPS itself.

•Creating electromagnetic interference (EMI) or radio frequency interference (RFI), which can disrupt the communication and data transmission of the ICT equipment.

•Triggering false alarms or tripping the circuit breakers of the UPS, which can cause downtime or data loss.

Therefore, fluorescent lights should not be connected to the same UPS that supports the ICT equipment. Instead, they should be connected to a separate power source, such as the utility power, the backup generator, or a different UPS.

Legal fees are an example of direct cost because they can be directly attributed to a specific project, product, or service. Legal fees are incurred for the purpose of obtaining legal advice, drafting contracts, resolving disputes, or complying with regulations related to the core business activity. Legal fees are not general overhead expenses that are shared by multiple cost objects.

The fire triangle is a simple model that illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). A fire naturally occurs when the elements are present and combined in the right mixture. A fire can be prevented or extinguished by removing any one of the elements in the fire triangle.

Fiber-optic cables use light as the source to transmit data. Light pulses are modulated to carry information through an optical fiber. The light is confined in the core of the fiber by total internal reflection at the core-cladding interface. The light travels along the fiber with minimal loss or interference, making it suitable for long-distance and high-bandwidth applications.

New equipment should be unpacked, tested, and configured in a dedicated staging room before being moved to the live data hall to prevent contamination and disruptions.

According to the EPI Data Centre Professional (CDCP®) Preparation Guide, Class K fires involve cooking appliances that use combustible cooking media such as vegetable or animal oils and fats (page 28). Class K fires require special extinguishing agents that can suppress the high-temperature flames and prevent re-ignition. Class K fires are different from Class B fires, which involve flammable liquids such as gasoline, oil, or paint.

The primary reason to install a monitoring system in the data centre is to notice abnormalities early so that actions can be taken to avoid disasters, according to the CDCP Preparation Guide1 and various web sources234. A monitoring system is a system that collects and analyzes data about the power, cooling, environmental, and security conditions in the data centre, and alerts the operators or managers about any issues or threats that may affect the performance, availability, or reliability of the data centre. A monitoring system can help to prevent or minimize the impact of disasters, such as power outages, fire, water damage, overheating, equipment failure, or cyberattacks, by providing timely and accurate information that enables fast and corrective action. A monitoring system can also help to improve the energy efficiency, capacity planning, and asset management of the data centre, by providing useful insights and trends that support informed decision making.

A service corridor is a dedicated space within or adjacent to a data centre that allows access to the supporting facilities, such as power, cooling, fire suppression, security, and cabling systems, without interfering with the computer room operations. A service corridor helps to isolate the noise, vibration, heat, and dust generated by the supporting facilities from the sensitive equipment in the computer room. A service corridor also enhances the safety and efficiency of the maintenance and monitoring activities, as well as the flexibility and scalability of the data centre design.

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.

Back-up generators are essential for providing power to the data centre in case of a utility outage. However, back-up generators also generate a lot of heat, which needs to be dissipated by a cooling system. The cooling system may rely on water supply, either from the municipal network or from a dedicated tank. If the water supply fails, the cooling system may not function properly, leading to overheating and potential damage to the generators. This could compromise the reliability and availability of the data centre power supply and cause downtime or data loss.

According to the EPI Data Centre Training Framework, an isolation transformer is a device that transfers electrical power from one circuit to another without changing the voltage or frequency, but providing galvanic isolation1. Galvanic isolation means that there is no direct electrical connection between the input and output circuits, which can prevent ground loops, reduce noise, and improve safety2. An isolation transformer can also provide voltage stepdown or stepup, create a local ground-bonded neutral, reduce harmonic currents, and provide taps for abnormal mains voltage3.

The location of the isolation transformer in relation to the ICT equipment depends on the purpose and design of the transformer. In general, the isolation transformer should be as close as possible to the ICT equipment, but taking into account potential EMF4. EMF is a form of electromagnetic interference (EMI) that can affect the performance and reliability of the ICT equipment5. The closer the isolation transformer is to the ICT equipment, the shorter the cable length and the lower the voltage drop and power loss4. However, the isolation transformer should also be far enough from the ICT equipment to avoid EMF, which can be reduced by using proper shielding, grounding, and spacing5.

The isolation transformer should not be installed as far away as possible to the ICT equipment, as option B suggests, because this would increase the cable length and the voltage drop and power loss4. The isolation transformer does not have to be installed within the power entry point of the building, as option C suggests, because this is not a requirement of the electrical code or regulation, and it may not be optimal for the data centre power system. The isolation transformer should not be installed within the rack in which the ICT equipment has been installed, as option D suggests, because this would increase the heat load and the noise level in the rack, and it may not fit in the rack space.

Damaged brand perception is an example of an indirect cost because it is not directly related to a specific product or service, but rather to the overall reputation and image of the company. Damaged brand perception can result from various factors, such as poor quality, customer dissatisfaction, security breaches, or negative publicity. Damaged brand perception can affect the company’s ability to attract and retain customers, partners, and investors, and thus reduce its profitability and competitiveness.

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.

Data centres are essential for supporting the IT operations and applications of various businesses across different industries. Data centre downtime can have a negative impact on the business results, such as loss of revenue, customer satisfaction, productivity, reputation, and competitive advantage. According to a web search, the average cost of data centre downtime in 2020 was $8,851 per minute, and the average duration of a data centre outage was 95 minutes1. This means that a typical data centre outage could cost a business over $840,000 in direct and indirect losses1. Therefore, data centre downtime can have a significant impact on the business results, regardless of the industry or sector.

A design consideration that should be implemented with an Inergen-based fire suppression system is to install pressure relief valves in the room that needs protection. Inergen is a clean agent fire suppression system that uses a mixture of inert gases (nitrogen, argon, and carbon dioxide) to displace the oxygen in the room and extinguish the fire. However, when Inergen is released into the room, it creates a sudden increase in pressure, which can damage the walls, doors, windows, and ceilings of the room. To prevent this, pressure relief valves are required to vent the excess pressure to the outside and maintain a safe pressure level inside the room. Pressure relief valves should be designed and installed in accordance with the relevant standards and codes, such as NFPA 2001 and ISO 14520.

Mean time between failures (MTBF) is a measure of the reliability of a system or component. It represents the average time that a system or component will operate before it fails. The higher the MTBF, the more reliable the system or component is. MTBF is calculated by dividing the total time of operation by the number of failures that occur during that time. MTBF is used to compare the reliability of similar systems or components, and to help with maintenance planning, inventory management, and system design.