Certified Energy Auditor Certification Lighting and Electrical Systems 2 — Questions and Answers
Question 1: What is the Color Rendering Index (CRI) minimum value recommended for office environments to maintain visual comfort?
- CRI 60
- CRI 70
- CRI 80 (Correct answer)
- CRI 95
Correct answer: CRI 80
A CRI of 80 or above is the standard recommendation for office environments to ensure accurate color perception and visual comfort.
Question 2: Which ballast type provides the highest energy efficiency for fluorescent lamps?
- Magnetic ballast
- Electronic ballast (Correct answer)
- Hybrid ballast
- Reactor ballast
Correct answer: Electronic ballast
Electronic ballasts operate at high frequency (20,000+ Hz), eliminating flicker and reducing energy losses compared to magnetic ballasts.
Question 3: A building's power factor is 0.72. Which corrective measure would most directly improve this at the source?
- Adding capacitor banks (Correct answer)
- Replacing incandescent lamps with LEDs
- Installing a transformer
- Upgrading to higher voltage distribution
Correct answer: Adding capacitor banks
Capacitor banks supply reactive power locally, reducing the reactive current drawn from the utility and improving the power factor.
Question 4: What does the term 'lamp lumen depreciation' (LLD) refer to in lighting audits?
- The voltage drop across the lamp over time
- The reduction in light output as a lamp ages (Correct answer)
- The decrease in color temperature at end of life
- The drop in power factor for aging ballasts
Correct answer: The reduction in light output as a lamp ages
LLD describes the predictable decline in lumens produced by a lamp over its rated life, which affects maintained illuminance calculations.
Question 5: An energy auditor finds demand charges constitute 40% of the facility's electric bill. Which strategy directly reduces demand charges?
- Switching to lower-wattage lamps
- Installing occupancy sensors to reduce run hours
- Implementing peak load shifting with lighting controls (Correct answer)
- Replacing T12 fixtures with T8 fixtures
Correct answer: Implementing peak load shifting with lighting controls
Demand charges are based on peak 15- or 30-minute intervals; shifting or curtailing lighting loads during peak periods directly lowers the billed demand.
Question 6: Which wiring configuration is required by NEC Article 410 for fixtures installed in a clothes closet?
- Any fixture type is permitted if guarded
- Surface-mounted incandescent fixtures are prohibited (Correct answer)
- Only recessed incandescent fixtures are allowed
- Fluorescent fixtures are prohibited
Correct answer: Surface-mounted incandescent fixtures are prohibited
The NEC prohibits incandescent or fluorescent fixtures with open or partially enclosed lamps in clothes closets due to fire risk from proximity to stored items.
Question 7: In a lighting power density (LPD) audit, which metric is used to compare a building's lighting system to ASHRAE 90.1 baselines?
- Watts per square foot (Correct answer)
- Lumens per watt
- Foot-candles per watt
- Kilowatt-hours per year
Correct answer: Watts per square foot
ASHRAE 90.1 LPD limits are expressed in watts per square foot (W/ft²), making this the direct comparison metric in a lighting audit.
