Exin EPI Certified Data Centre Specialist CDCS Exam Practice Test

Answer : B

The data center life cycle is typically divided into four stages:

Design (scope, architecture, planning)

Implement (construction, installation, testing & commissioning)

Operate/Optimize (day-to-day operations, maintenance, continuous improvement)

Retire (decommissioning and migration)

Testing and commissioning occur in the Implement stage, after construction but before handover. This includes Integrated Systems Testing (IST), which validates that all systems (electrical, cooling, fire protection, telecom) perform to design intent and redundancy requirements.

Without commissioning, the data center cannot be certified or considered operational.

Answer : C

Perforated tiles with integrated dampers are common in raised-floor data centers because they allow airflow regulation at the rack level. However, even when the damper is fully open, the mechanism inside the tile restricts airflow. This typically reduces the delivered airflow by around 10% compared to a non-dampered tile of the same type.

Option A is incorrect because dampers do not affect supply temperature; they only throttle volume.

Option B is wrong since dampers cannot increase volume---they only add resistance.

Option D is partially true that dampers help with temperature balancing, but the main effect (in open position) is volume reduction.

Thus, the technical impact of dampers in open position is a slight airflow reduction, usually quantified as ~10%.

Answer : B

High relative humidity (above 80%) creates a serious risk for corrosion of electronic contacts, printed circuit boards (PCBs), and metallic components. Moisture in the air condenses more easily, especially when surfaces are cooler than ambient dew point. This can lead to oxidation of connectors, degradation of solder joints, and eventual failures in ICT hardware.

Electrostatic discharge (ESD) risks, by contrast, increase at low humidity (below 30%) because dry air promotes charge buildup. Therefore, option C is incorrect here. Similarly, option D (cooling risk from wet-bulb temperature) applies to evaporative cooling efficiency, not directly to ICT risk.

ASHRAE recommends data centers maintain RH between 40--60% for optimal reliability. Values above 80% RH are considered outside the recommended operating envelope and significantly increase the risk of corrosion, especially in the presence of airborne contaminants like sulfur dioxide (SO) or hydrogen sulfide (HS).

Therefore, the verified risk at 85% RH is corrosion-related degradation.

Answer : C

A 6-pulse thyristor rectifier typically produces 25--35% THDi at nominal load. To reach 3% THDi, an active harmonic filter (or a 12/18-pulse or IGBT rectifier UPS) is required. Passive filters are load-specific and less effective over a wide operating range---undesirable with frequent changes.

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Answer : A

Design concentrations for halocarbons (e.g., FM-200/HFC-227ea, Novec 1230) increase with ambient temperature; higher temperature higher minimum extinguishing concentration more agent mass.

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Answer : D

Design changes during the implementation phase are generally allowed only when there is a strong business and/or technical justification. Changes at this stage can lead to delays, increased costs, or compromise design integrity. Thus, a rigorous assessment is required to ensure any modifications are essential and provide clear benefits or address critical issues.

Detailed Explanation:

Changes post-design freeze should be minimized to avoid scope creep and additional costs. However, if a technical issue arises that would affect operational goals, or a business need warrants modification, justified changes are permissible, following an impact assessment and approval process.

EPI Data Center Specialist Reference:

EPI project management guidelines recommend a controlled change management process during implementation, allowing changes only when they align with critical objectives or address unforeseen issues that affect the project's success.

Answer : B

ASHRAE TC 9.9 recommends using dust deposition coupons (also called reactivity coupons) to measure particulate contamination over time. These are small, standardized metallic plates exposed to the air that collect dust and contaminants. After a set period, they are analyzed for chemical corrosion rates and particulate buildup.

Option A (handheld analyzers) gives spot counts of airborne particles but does not capture long-term corrosive deposition risk.

Option C only samples underfloor plenum dust, not actual IT environment contamination.

Option D (opening equipment) is invasive and risks voiding warranties.

Coupons provide standardized, passive, and reliable monitoring of contamination over months, making them the preferred method.