FREE CDCP Data Center Cooling Questions and Answers

Question 1

What can you do if the top sensor on a rack displays a high temperature alarm?

Accepted Answer

Check blanking panel placement

Answer

Blanking panels are crucial for maintaining proper airflow within a server rack by preventing hot exhaust air from recirculating into the cold aisle. If a top sensor shows high temperature, it often indicates that hot air is bypassing equipment, possibly due to missing or improperly placed blanking panels. Ensuring all unused rack spaces are sealed with blanking panels directs cool air efficiently through the equipment, preventing hot spots.

Question 2

What should you check first if your cooling tower alarms for a high water temperature?

Accepted Answer

Check to see if fan is running

Answer

A cooling tower's primary function is to dissipate heat from water through evaporation, which is facilitated by a large fan drawing air through the tower. If the water temperature is high, the most immediate and critical check is to ensure the fan is operational. A non-functioning fan would prevent proper heat rejection, leading to elevated water temperatures.

Question 3

What results in a CRAC unit's low-pressure alarm?

Accepted Answer

All of the above

Answer

A low-pressure alarm in a CRAC unit typically indicates an issue with the refrigerant cycle or airflow. Dirty filters restrict airflow, causing the evaporator coil to run colder and potentially leading to low suction pressure. Loss of refrigerant directly reduces system pressure, while a blower motor failure or improperly adjusted belts would reduce airflow over the coil, impacting heat exchange and causing pressure drops. All these factors can contribute to a low-pressure alarm.

Question 4

What is the main mechanical distinction between computer room air handlers (CRAHs) and CRACs?

Accepted Answer

CRACs have refrigeration compressors as part of their primary system

Answer

The fundamental difference between CRACs (Computer Room Air Conditioners) and CRAHs (Computer Room Air Handlers) lies in their cooling mechanism. CRAC units are self-contained refrigeration systems that include their own compressors, condensers, and evaporators to directly cool and dehumidify air. CRAH units, on the other hand, rely on an external chilled water supply from a chiller plant and do not have integrated refrigeration compressors.

Question 5

Which of the following benefits of "cold aisle confinement" is NOT one of them?

Accepted Answer

No need for ‘tile management’

Answer

Cold aisle containment aims to separate cold supply air from hot exhaust air, significantly improving cooling efficiency and predictability. While it offers benefits like better temperature control and increased HVAC efficiency, it does not eliminate the need for 'tile management.' Proper placement and type of perforated tiles are still essential to ensure adequate airflow and pressure within the contained cold aisle and to deliver cooling precisely where needed.

CDCP - Certified Data Centre Professional Practice Test

CDCP - Certified Data Centre Professional Practice Test

FREE CDCP Data Center Cooling Questions and Answers