EGSA Power Generation Equipment 2

Question 1

What is the primary function of an automatic voltage regulator (AVR) in a generator set?

Accepted Answer

Maintain constant output voltage under varying loads

Answer

An AVR senses output voltage and adjusts excitation current to keep generator terminal voltage stable as load changes.

Question 2

In a diesel generator, what does the term 'wet stacking' describe?

Accepted Answer

Unburned fuel and oil accumulating in the exhaust system

Answer

Wet stacking occurs when a diesel engine runs at light load for extended periods, causing unburned fuel and carbon deposits to accumulate in the exhaust stack.

Question 3

Which generator winding configuration provides both 120V and 240V single-phase output from the same alternator?

Accepted Answer

Center-tapped single-phase winding

Answer

A center-tapped single-phase winding allows both 120V (line-to-neutral) and 240V (line-to-line) to be derived from the same winding.

Question 4

What is the purpose of a droop governor setting on a generator operating in parallel?

Accepted Answer

Allow proportional load sharing between paralleled generators

Answer

Droop governor settings cause engine speed to decrease slightly as load increases, enabling stable proportional load sharing when multiple generators run in parallel.

Question 5

What is the typical standby power rating for a generator set?

Accepted Answer

Maximum power available for up to 200 hours per year with varying load

Answer

Standby rating represents maximum power for emergency use, typically not exceeding 200 hours per year at varying load with no average load factor limit.

(EGSA) Electrical Generating Systems Association Certified Practice Test

(EGSA) Electrical Generating Systems Association Certified Practice Test

EGSA Power Generation Equipment 2