CEM Lighting Systems 5

Question 1

A facility has 500 luminaires each with two 32W T8 lamps and a ballast consuming 6W. What is the total connected lighting load in kW?

Accepted Answer

35 kW

Answer

Power per luminaire = 2×32 + 6 = 70W; total = 500 × 70W = 35,000W = 35 kW.

Question 2

Which photometric measurement describes luminous intensity distribution in a plane containing the luminaire's axis, used to generate isolux diagrams?

Accepted Answer

Candlepower distribution curve

Answer

Candlepower distribution curves (polar intensity plots) show how a luminaire distributes light in specific planes, enabling isolux calculations.

Question 3

Stroboscopic effect in lighting is a concern primarily because:

Accepted Answer

It can make rotating machinery appear stationary, creating safety hazards

Answer

When light flickers at frequencies matching the rotation speed of machinery, equipment can appear stationary, posing serious workplace safety risks.

Question 4

A lighting energy audit reveals that a building operates lights 24/7 in spaces unoccupied at night. Installing occupancy sensors reduces operating hours from 8,760 to 5,000 hours/year. If lighting uses 50 kW, what is the annual energy savings at $0.10/kWh?

Accepted Answer

$18,800

Answer

Hours saved = 8,760 – 5,000 = 3,760 h; savings = 50 kW × 3,760 h × $0.10 = $18,800.

Question 5

Which commissioning activity verifies that installed lighting controls perform as specified after construction is complete?

Accepted Answer

Functional performance testing

Answer

Functional performance testing (a commissioning process) verifies that sensors, dimmers, and scheduling controls operate correctly under real conditions.

(CEM) Certified Emergency Manager Practice Test

(CEM) Certified Emergency Manager Practice Test

CEM Lighting Systems 5