2ND 12

Question 1

Voltage drop in a distribution system may be overcome by:

a) changing from an overhead to an underground system
b) using load tap changing transformers
c) using feeder voltage regulators
d) all three

Answer 1

d) all three

Question 2

Which of the following statements concerning regulated feeder voltage is not true?

a) the degree of illumination provided by incandescent lamps will not be affected by variations of voltage in the order of one percent
b) electric motors run better when operated at their rated voltage
c) an increase in revenue is obtained by the utility when feeder voltages are maintained within prescribed limits
d) a well designed feeder voltage regulation system can decrease the utility investment per KVA distributed

Answer 2

a) the degree of illumination provided by incandescent lamps will not be affected by variations of voltage in the order of one percent

Question 3

The principle of operation of a feeder voltage regulator is very similar to that of a:

a) condenser
b) transformer
c) capacitor
d) reactor

Answer 3

b) transformer

Question 4

In a induction type voltage regulator:

a) both primary and secondary windings are stationary
b) both primary and secondary windings rotate
c) only the secondary winding rotates
d) only the primary winding rotates

Answer 4

d) only the primary winding rotates

Question 5

The purpose of the short-circuit winding in an induction type voltage regulator is to:

a) control voltage drop
b) protect against high voltage
c) regulate constant voltage
d) none of the above

Answer 5

a) control voltage drop

Question 6

Which one of the following statements most nearly describes the operating principle of a step type voltage regulator:

a) variable ratio auto-transformer
b) auto-transformer
c) auto-transformer with taps
d) auto-transformer with taps and a reversing switch

Answer 6

d) auto-transformer with taps and a reversing switch

Question 7

The total number of 5/8 percent voltage steps provided in most step type voltage regulators is:

a) 32
b) 16
c) 9
d) 8

Answer 7

a) 32

Question 8

The kind of insulating coolant preferred for use in the step type voltage regulator is:

a) Askarel
b) Pyranol
c) transformer oil
d) chlorinated hydrocarbon oil

Answer 8

c) transformer oil

Question 9

A ground feeder system using step type voltage regulators will require:

a) three regulators connected closed-Delta
b) two regulators connected Wye
c) open-Delta regulators with grounded neutral
d) three regulators Wye-connected with a common neutral

Answer 9

d) three regulators Wye-connected with a common neutral

Question 10

Two fully loaded 10 percent regulators are supplying a balanced three-phase load of 600 amps at 2400 volts. What is the rating of each regulator?

a) 144 MVA
b) 288 KVA
c) 249 KVA
d) 144,000 VA

Answer 10

d) 144,000 VA