In: Electrical Engineering
Please answer the following questions in "Energy Efficiency Basics" multiple choice:
QUESTION 7
An electrical system has 52.9 kVA and 50.5 kW. How many kVARs of
capacitance are required to correct the power factor of the total
load to 95%? a. 10.8 kVARs
a 0 kVARs
b 20 kVARs
c 35 kVARs
d 75 kVARs
QUESTION 8
You find that you can replace a 50 kW motor with a 5 kW motor by
cutting the total air flow requirements, given than ( motor running
time is 8,750 hours/year, efficiency 90% for both motors, demand
charge $ 9 /kW-month, energy charge $0.05/kWh fuel adjustment cost
$0.005/kwh). Calculate the dollar savings ?
a $ 29,490
b $20,400
c $22,090
d $14,010
QUESTION 9
An air handler delivers 1,200 L/s of air at 10 ºC. When the air
arrives at the space to be cooled, it is 20 ºC. How many kW of air
conditioning capacity has been lost?
a 6 kW
b 14.4 kW
c 12.1 kW
d 20 kW
QUESTION 10
If a 75-kW fan motor has a VSD installed that slows down the fan by
20% what is the effect on air flow rate and the kW savings?
a 20% CFM reduction, and 36.6 kW savings
b 80% CFM reduction, and 51.2 kW savings
c 20% CFM reduction, and 20 kW savings
d 20% CFM reduction, and 37.4 kW savings
QUESTION 11
In a given facility you measure the incoming supply 3 phase voltage
and you find the following voltages present. 236V 231V 227V. What
impact is this likely to have on the motor load in the
installation? imbalance?
a Increase motor losses by approx. 7%
b Increase motor losses by approx. 15%
c Reduce motor losses by approx. 7%
d Reduce motor losses by approx. 15%