CDCP Certified Data Centre Professional (CDCP) Questions and Answers

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.

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.

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.

Measuring “Business Values” begins first with budgeting and identifying the costs associated with the project. This includes understanding the economic impact of the project, such as the cost of labor, materials, and other resources. It is also important to evaluate the return on investment (ROI) of the project, which will help to determine its overall value. Additionally, it is important to consider the long-term impact of the project and its potential to add value to the business in the future.

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.

The casters and feet under the rack are used to support the weight of the rack and its equipment, and to allow the rack to be moved if needed. However, the casters and feet should also be designed to avoid putting too much pressure on the floor tile, especially if the data centre uses a raised floor system. A too heavy point load on the floor tile can cause the tile to crack, deform, or collapse, which can damage the rack, the equipment, and the underlying infrastructure. To prevent this, the casters and feet should be larger, so that they can distribute the weight over a larger area and reduce the point load. The casters and feet should also be compatible with the floor type and the load rating of the floor tile.

A steam canister humidifier is a type of humidifier that uses electricity to heat water in a canister containing electrodes. The water conductivity and the water level determine the amount of current and steam production. The steam canister humidifier is also known as an electrode boiler humidifier or an electrode steam humidifier123.

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.

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.

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.

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.

A UPS (Uninterruptible Power Supply) is a device that provides backup power to electrical equipment in case of a power outage or fluctuation. A UPS is essential for both CCTV cameras and recording equipment, as it ensures that the surveillance system can continue to operate and record without interruption or data loss. A UPS can also protect the CCTV cameras and recording equipment from damage caused by power surges or spikes. Connecting both CCTV cameras and recording equipment to a UPS is a requirement for data centres, as it enhances the security and reliability of the surveillance system.

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.

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.

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.

According to the EPI Data Centre Professional (CDCP®) Reference Materials, the recommended number of monitoring points for temperature measurement in a data centre is 3 per rack: one at the top, one at the middle, and one at the bottom1. This is to ensure that the temperature distribution within the rack is uniform and within the acceptable range for the equipment. The temperature sensors should be placed at the front of the rack, where the air enters the equipment, and not at the back, where the hot air exits1.

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.

According to the EPI Data Centre Professional (CDCP®) Preparation Guide, failure is defined as “the termination of the ability of a product to perform its required function” (page 9). Failure can occur due to various reasons, such as wear and tear, design flaws, human errors, environmental factors, or external events. Failure can affect the availability, reliability, and performance of a product, system, or service.

VESDA (Very Early Smoke Detection Apparatus) or HSSD (High Sensitivity Smoke Detection) systems are the fastest smoke sensors among the options listed. These systems use a network of pipes to draw air samples from the protected area and analyze them using a laser-based detection chamber. VESDA/HSSD systems can detect smoke at very low concentrations, typically in the range of 0.005 to 20 percent obscuration per meter. This means they can provide early warning of a fire before it becomes visible or spreads. VESDA/HSSD systems are ideal for data centers and other critical facilities that require high levels of fire protection and minimal downtime.

8760 is the number of hours in a year (24 hours × 365 days). Dividing annual revenue by 8760 gives a basic average revenue per hour, commonly used in downtime cost calculations.

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 main difference between an Environmental Monitoring System (EMS) and a Building Management System (BMS) is that an EMS monitors only, while a BMS monitors and controls. An EMS is a system that collects and records data from various sensors and devices that measure environmental parameters, such as temperature, humidity, air quality, power, and water. An EMS provides alerts and reports based on the data, but it does not control or adjust the environmental conditions. A BMS is a system that integrates and manages various building systems, such as HVAC, lighting, security, fire, and access. A BMS not only monitors the data from these systems, but also controls and optimizes them to achieve the desired performance and efficiency. A BMS can also communicate with an EMS to receive data and provide feedback.

Optical fiber cables are composed of a core, a cladding, and a coating. The core is the central part of the fiber that carries the light signal. The cladding is the layer surrounding the core that reflects the light back into the core and prevents signal loss. The coating is the protective layer that covers the cladding and provides mechanical strength and environmental protection. The specifications of an optical fiber cable indicate the dimensions of the core and the cladding in microns (μm), which are one millionth of a meter. For example, a 50/125 μm cable has a core diameter of 50 μm and a cladding diameter of 125 μm. The coating diameter is usually 250 μm, but it is not part of the specifications.