Exin EXIN EPI Certified Data Centre Specialist CDCS Exam Dumps: Updated Questions & Answers (October 2025)

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.

Battery charging current is typically sized at 10% of the total Ah capacity to ensure safe charging without overheating.

Charging Current=800Ah×0.1=80A

40 A or 60 A would undercharge, extending recovery time after discharge.

160 A would be too high, causing heat and reducing battery life.

Thus, 80 A is correct.

An End of Row (EoR) design minimizes the number of network switches, as multiple racks can share a single switch at the end of a row, reducing switch counts and simplifying management. This design centralizes network switching to fewer points, which reduces the complexity and number of switches required compared to a Top of Rack (ToR) design, where each rack typically has its own switch.

Detailed Explanation:

In EoR designs, each row has a single network switch that handles the connections for all racks within that row. This reduces the number of individual switches needed and centralizes network management, which is ideal for minimizing equipment and simplifying infrastructure in the data center.

EPI Data Center Specialist References:

EPI promotes the EoR design as a way to reduce switch counts and streamline management in data centers. This configuration allows for easier scaling and maintenance while maintaining efficient network connectivity.

The life cycle begins with planning and design. The very first step is to clearly define the project scope: business requirements, capacity, availability targets, compliance standards, and budget. Without scope definition, design validation or vendor selection would be premature.

Vendor selection (A) happens much later during procurement.

Validation (B) occurs after conceptual and detailed designs are prepared.

Freezing design (D) is the final stage before implementation.

Therefore, defining the project scope is the correct initial step.

In areas with frequent and extended power outages, continuous generators with at least an N+1 configuration are necessary to ensure consistent power availability. Continuous generators are designed for prolonged operation, making them suitable for scenarios where utility power is frequently unavailable, as in this case with outages exceeding 650 hours per year. An N+1 configuration ensures redundancy, which is critical for maintaining uptime in a high-availability data center.

Detailed Explanation:

Continuous generators provide reliable power over long durations, unlike standby generators, which are intended only for short-term use. The N+1 configuration ensures that there is always an additional generator available in case of failure, thus maintaining power supply even if one generator goes offline.

EPI Data Center Specialist References:

EPI best practices recommend continuous generators with redundancy for data centers located in areas with high power instability to maintain reliability and continuous operation.

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.

The aisle pitch is the total width of a rack row plus cold aisle plus rack row. For 1.0 m racks on each side with cold aisle containment, ASHRAE and TIA-942 recommend the 7-tile rule (each tile ~0.6 m). This ensures enough width for equipment clearance, airflow distribution, and human access.

5-tile pitch is too narrow, restricting containment effectiveness.

8–10 tiles may be used in some hyperscale layouts but are not standard for 1 m racks.

Thus, the correct design recommendation is the 7 tiles pitch rule.

Electromagnetic field (EMF) strength around cables is primarily influenced by current, not voltage. In a single-phase system, the live and neutral conductors are separated, creating a larger magnetic loop area. This produces stronger stray EMF when current increases.

In a balanced three-phase system, the magnetic fields from the three conductors largely cancel each other out, resulting in much lower net EMF, even at higher currents.

Therefore, the correct statement is that increasing current in single-phase cables produces higher EMF compared to three-phase cables. Options B, C, and D incorrectly link EMF to voltage or incorrect current behavior.

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.

Residual current protection has evolved:

ELCB (Earth Leakage Circuit Breaker): Older type; voltage-operated. It trips when voltage develops between earth and exposed metal.

RCD/RCCB (Residual Current Device/Circuit Breaker): Current-operated. It detects imbalance between live and neutral conductors (indicating leakage current to earth).

Modern data centers use RCDs/RCCBs exclusively, since ELCBs are obsolete and unreliable if multiple earth connections exist. Thermal-magnetic breakers (D) provide overcurrent protection, not earth leakage.

Thus, not all residual current devices are based on the same principle.