Certified Energy Auditor Certification Lighting and Electrical Systems 5

Question 1

Which lighting source type has the highest luminous efficacy available in commercial products as of current standards?

Accepted Answer

LED

Answer

Commercial LED luminaires routinely achieve 150–200+ lm/W system efficacy, surpassing all other available commercial lamp technologies.

Question 2

A facility operates at 480V three-phase. A voltage imbalance test shows Phase A = 478V, Phase B = 462V, Phase C = 482V. What is the approximate percent voltage imbalance?

Accepted Answer

2.6%

Answer

Average = (478+462+482)/3 = 474V; max deviation = 474−462 = 12V; imbalance = 12/474 × 100 ≈ 2.5%, closest to 2.6%.

Question 3

What is the purpose of a 'lighting power allowance' in ASHRAE 90.1's Building Area Method?

Accepted Answer

To set the maximum allowable LPD for an entire building based on its primary use type

Answer

The Building Area Method assigns a single maximum W/ft² allowance to the whole building based on its primary classification (e.g., office, retail, warehouse).

Question 4

An auditor identifies induction motors running at 60% load as a major reactive power source. Which device placed near the motors would most efficiently correct the power factor locally?

Accepted Answer

Power factor correction capacitors

Answer

Capacitors installed at or near motor terminals supply reactive power locally, reducing reactive current in the upstream distribution system and improving facility power factor.

Question 5

What is the significance of the 'Useful Life' rating (L70) for LED luminaires in an energy audit?

Accepted Answer

The hours at which lumen output has depreciated to 70% of initial output

Answer

L70 defines the operating hours at which a LED luminaire's light output has declined to 70% of its initial lumens, the industry standard threshold for end of useful life.

Certified Energy Auditor Certification Practice Test

Certified Energy Auditor Certification Practice Test

Certified Energy Auditor Certification Lighting and Electrical Systems 5