CDCS Exam Dumps : EXIN EPI Certified Data Centre Specialist

Hot and cold aisle containment prevents mixing of supply and return air, which improves cooling efficiency. By maintaining higher return-air temperatures, cooling units operate more efficiently, often allowing higher chilled water setpoints. This reduces overall cooling power consumption, directly improving PUE (Power Usage Effectiveness).

Containment is recognized by ASHRAE and Green Grid as one of the simplest and most cost-effective methods for lowering PUE. Options A, C, and D are false because containment benefits apply regardless of cooling source or IT virtualization.

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.

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.