Free Exin CDCS Exam Dumps May 2026

According to ASHRAE TC 9.9 Thermal Guidelines (2016), the recommended intake temperature range for Class A1 ICT equipment is 18--27 C (64--81 F). The allowable lower limit is 15 C (59 F). Setting supply to 4 C (39 F) falls far below these limits.

Operating at such low temperatures would:

Cause condensation risk when surfaces drop below dew point.

Create severe energy inefficiency, as chillers would run at extremely low setpoints.

Possibly damage hardware due to thermal shock.

Options A and B are misleading---system capability or dew point alone does not override ASHRAE guidelines. Option D is incorrect since 20 C is a common design target, not a requirement.

Thus, supplying 4 C is not acceptable.

MCBs (Miniature Circuit Breakers) are characterized by their tripping curves:

B-Curve: Trips at 3--5 rated current; suitable for resistive loads.

C-Curve: Trips at 5--10 rated current; suitable for mixed loads including ICT equipment with moderate inrush current.

D-Curve: Trips at 10--20 rated current; used for heavy inductive loads like motors.

A-Curve: Very sensitive, rarely used outside specialty electronics.

Since ICT equipment like servers and network devices have moderate inrush currents (from power supplies), the recommended breaker is C-Curve. It balances protection against nuisance tripping while still ensuring fault clearance.

A 2(N+1) configuration implies two independent UPS systems, each with N+1 redundancy. This configuration provides high availability by ensuring that each UPS system can independently support the load with an additional unit for redundancy. Given the 80 kW load, this setup implies that two separate N+1 systems are running, providing reliability and fault tolerance for the data center's power needs.

Detailed Explanation:

The N+1 notation denotes that each system has one additional unit beyond what is needed to carry the load, providing redundancy. With 2(N+1), there are two such setups, ensuring that if one fails, the other can still support the load without interruption, fulfilling high availability requirements.

EPI Data Center Specialist Reference:

EPI teaches that multiple redundant systems, such as 2(N+1), enhance data center reliability by ensuring that power is maintained even if a failure occurs in one system. This meets the stringent demands for uptime in critical environments.

OM5 is optimized for Short Wavelength Division Multiplexing (SWDM) between 850--953 nm. This allows transmission of multiple wavelengths over a single fiber pair, reducing the number of fibers required for high-speed links.

OM4 already supports 100 GbE to 150 m, but OM5 with SWDM extends reach and reduces cabling bulk.

Option B is false because OM5 offers distinct SWDM benefits.

Option C is incorrect---OM5 is laser-optimized, not LED-based.

Option D is misleading; OM5 doesn't extend 100 GbE to 500 m (that requires single-mode OS2 fiber).

Thus, the key advantage is SWDM support.