CDCP Exam Dumps : Certified Data Centre Professional (CDCP)

As per Certified Data Centre Professional (CDCP®) reference materials, Common Mode Noise (CMN) is a type of electrical noise that appears equally on the line and neutral wires with respect to ground, and it can negatively affect sensitive ICT equipment. Excessive CMN at the rack level can lead to data errors, communication problems, equipment malfunctions, or even hardware damage.

The CDCP® training and the official exam preparation guide specify that the preferred level of Common Mode Noise at the rack should be less than 1 Volt, and under no circumstances should it exceed 3 Volts. Keeping CMN at these levels helps ensure the stable and reliable operation of critical data center infrastructure. Higher CMN levels indicate grounding or bonding issues, or possibly interference from electrical or mechanical sources, and must be addressed promptly.

Options A and B (CMN above 5 or 10 Volts) are not acceptable and would present a serious risk to ICT equipment operation and data integrity. Option D is incorrect, as CMN absolutely does affect ICT equipment.

According to the Certified Data Centre Professional (CDCP®) reference materials, ICT (Information and Communication Technology) equipment such as servers, switches, and storage devices generate sensible heat. Sensible heat is the heat energy that causes a change in temperature of the air but does not contribute to humidity or moisture content. This is in contrast to latent heat, which involves a change in moisture (humidity) in the air, such as from evaporation or condensation.

ICT equipment does not introduce moisture into the environment; it only raises the temperature of the surrounding air, making it sensible heat. Proper data center cooling focuses on removing this sensible heat load to maintain optimal equipment operating conditions. Latent heat loads, such as those from people or water leaks, are typically not generated by ICT equipment and are managed differently in facility design.

Radiant heat is a minor consideration and typically refers to heat transferred by electromagnetic waves (e.g., from sunlight or hot surfaces), not the primary mode of heat transfer from ICT equipment, which is primarily through convection (airflow) and is measured as sensible heat.

Class C fires involve energized electrical equipment, such as computers, servers, switches, cables, and wiring. These fires require the use of non-conductive extinguishing agents, such as carbon dioxide, dry chemical, or clean agent, to prevent electrical shock and damage to the equipment. Water-based extinguishers, such as Class A or K, are not suitable for Class C fires, as water can conduct electricity and cause electrocution or short circuits.