DCI Pathways and Spaces 2 — Questions and Answers
Question 1: What is the minimum clearance required above a suspended ceiling used as a plenum return air pathway when installing cable trays?
- 6 inches
- 12 inches (Correct answer)
- 18 inches
- 24 inches
Correct answer: 12 inches
A minimum of 12 inches of clearance is typically required above suspended ceilings used as plenum return air pathways to allow for proper airflow and cable management.
Question 2: Which standard governs the installation of cable trays in the United States?
- NFPA 70 (NEC)
- NEMA VE-1 (Correct answer)
- TIA-569
- ANSI/BICSI 002
Correct answer: NEMA VE-1
NEMA VE-1 is the standard that specifically governs the design and installation of metal cable trays in the United States.
Question 3: A conduit body that makes a 90-degree change in direction is commonly called a(n):
- LB fitting (Correct answer)
- Elbow sweep
- Offset nipple
- Service entrance head
Correct answer: LB fitting
An LB fitting (conduit body) is used to make a 90-degree change of direction in a conduit run while also providing a pull point.
Question 4: When pulling cable through a conduit, what is the maximum recommended fill ratio for a single cable?
- 31%
- 40%
- 53% (Correct answer)
- 60%
Correct answer: 53%
For a single cable in a conduit, the maximum recommended fill ratio is 53% of the conduit's cross-sectional area per NEC guidelines.
Question 5: In a data center, a hot aisle/cold aisle layout primarily affects which pathway and spaces consideration?
- Cable tray fill ratios
- Underfloor cable routing and airflow management (Correct answer)
- Conduit bending radius
- Firestopping requirements
Correct answer: Underfloor cable routing and airflow management
Hot aisle/cold aisle layouts directly impact underfloor cable routing and airflow management, as cables must be routed to avoid blocking cold air supply tiles.
Question 6: What term describes a pathway that runs horizontally between the telecommunications room and the work area outlets?
- Backbone pathway
- Horizontal pathway (Correct answer)
- Campus distributor run
- Interbuilding pathway
Correct answer: Horizontal pathway
A horizontal pathway runs horizontally from the telecommunications room (TR) to the work area telecommunications outlet/connectors.
Question 7: Which of the following is NOT a typical type of surface raceway used for horizontal cable distribution?
- Baseboard raceway
- Multiduct raceway
- Cellular floor raceway
- Cable tray ladder (Correct answer)
Correct answer: Cable tray ladder
A cable tray ladder is an overhead pathway system, not a surface raceway; baseboard, multiduct, and cellular floor systems are all types of surface raceways.
DCI Pathways and Spaces 2
What is the minimum clearance required above a suspended ceiling used as a plenum return air pathway when installing cable trays?