CDCS CDCS Power & Cooling Systems 2

Question 1

What is the ASHRAE A1 thermal envelope recommended inlet temperature range for most enterprise IT equipment?

Accepted Answer

59°F–89.6°F (15°C–32°C)

Answer

41°F–77°F (5°C–25°C)

Answer

32°F–68°F (0°C–20°C)

Answer

68°F–95°F (20°C–35°C)

Question 2

Which cooling technology uses water-chilled rear-door heat exchangers attached directly to server cabinets?

Accepted Answer

Rear-door heat exchanger (RDHx)

Answer

In-row cooling

Answer

Economizer free cooling

Answer

Computer room air handler (CRAH)

Question 3

What does N+1 redundancy mean in the context of data center UPS systems?

Accepted Answer

One additional UPS module beyond the minimum required for full load

Answer

One UPS module backs up the entire facility

Answer

All UPS modules run at 100% load

Answer

N UPS modules share load while one is offline for maintenance

Question 4

What is the primary advantage of using a hot-aisle containment (HAC) system over cold-aisle containment (CAC)?

Accepted Answer

HAC keeps the general room air cooler and safer for personnel

Answer

HAC lowers server inlet temperatures more effectively

Answer

HAC requires fewer perforated floor tiles

Answer

HAC eliminates the need for raised floor plenum

Question 5

Which metric describes the percentage of time a data center's power infrastructure is expected to be available per year?

Accepted Answer

Uptime percentage (nines)

Answer

PUE

Answer

DCiE

Answer

DCIE

Question 6

What is the function of a static VAR compensator (SVC) or active harmonic filter in a data center electrical system?

Accepted Answer

Mitigate harmonic distortion generated by non-linear IT loads

Answer

Provide backup power during utility outages

Answer

Step up voltage from utility feed to distribution level

Answer

Synchronize generator frequency with utility frequency