CDCS CDCS Power & Cooling Systems 3

Question 1

In data center power design, what does a 2N power path architecture mean?

Accepted Answer

Fully redundant dual power paths from utility to every rack outlet

Answer

Two generators feed one UPS

Answer

Two PDUs share a single UPS string

Answer

N servers are powered by 2 utility feeds without UPS

Question 2

What is an economizer (free cooling) mode in data center HVAC, and when is it most beneficial?

Accepted Answer

Leveraging cool outdoor air or water to reduce or eliminate mechanical chiller operation

Answer

Using reclaimed server heat to warm office spaces in winter

Answer

Cycling compressors off during peak electricity pricing

Answer

Directing hot aisle exhaust back to server inlets to reduce heating costs

Question 3

Which standard does BICSI TDMM follow for data center power and cooling infrastructure documentation?

Accepted Answer

TIA-942

Answer

ISO/IEC 24764

Answer

ASHRAE TC 9.9

Answer

EN 50600

Question 4

What does the term 'stranded capacity' refer to in data center power management?

Accepted Answer

Provisioned power capacity that is allocated but not actively consumed by IT loads

Answer

Utility power that cannot reach the data center due to grid constraints

Answer

Generator fuel that degrades and becomes unusable over time

Answer

UPS battery capacity lost due to thermal runaway events

Question 5

Which type of generator automatic transfer switch (ATS) can test the generator under load without interrupting the critical load?

Accepted Answer

Closed-transition (make-before-break) ATS

Answer

Open-transition ATS

Answer

Bypass isolation ATS

Answer

Soft-load transfer ATS

Question 6

What is the purpose of a flywheel UPS (FESS) compared to a traditional battery-based UPS?

Accepted Answer

A flywheel UPS stores kinetic energy to bridge the gap until generators start, offering higher power density and longer cycle life than batteries

Answer

A flywheel UPS provides longer runtime than batteries during extended outages

Answer

A flywheel UPS eliminates the need for a transfer switch

Answer

A flywheel UPS provides conditioned power without any energy storage