A 25-kW motor, at full load, drives a centrifugal fan that produces 160,000 liters per second (l/s) of ventilation air. If the fan speed is reduced to a flow rate of 150,000 l/s, what is the new load on the motor?
Which type of lighting control technique operates in "manual on" and "auto-off mode, and can be used in situations where there is brief occupancy that do not need lights on?
A three phase, 380.volt system has the following voltage measurements:
Va = 375$ volts
Vb = 380$ volts
Vc = 391$ volts
Calculate the percent voltage imbalance.
SELECT THE CORRECT ANSWER
An outdoor parking area has 25 light poles. Each pole has a 420 Watt (ballast included) high-pressure sodium (HPS) luminaire. The parking area lights are illuminated 4,500 hours per year and the electricity cost is $0.08
/kWh. What is the annual energy cost reduction if each luminaire is replaced with a 220-Watt (driver included) LED luminaire?
The primary advantage of predictive maintenance over preventive maintenance in building energy systems, is that predictive maintenance:
SELECT THE CORRECT ANSWER
