Generator

Question 1

What is the purpose of the day tank in a generator system?

Answer 1

To allow for the use of the generators without power until the fuel pumps can be powered by the generators themselves.

Question 2

What is directly proportional to speed on a generator?

Answer 2

Frequency

Question 3

What causes wet stacking on a diesel generator?

Answer 3

Fuel and moisture in stack from running with no load.

Question 4

What is fuel polishing?

Answer 4

Process of cleaning fuel through filtration and separation.

Question 5

What does an ATS monitor while on utility power in order to determine when to transfer to SEP?

Answer 5

Utility power

Question 6

Why is the engine coolant kept warm on an offline generator?

Answer 6

To facilitate fast start-up

Question 7

What does “synchronizing” two generators mean?

Answer 7

Bring together on same bus with volts, frequency and phases in alignment

Question 8

What is an over-crank alarm on a generator?

Answer 8

Alarm indicates the generator starter ran too long without a generator start.

Question 9

What is the purpose of an Automatic Transfer Switch?

Answer 9

Transfer power from one source to another source

Question 10

Time delays are used in ATS to do what?

Answer 10

To verify stable source prior to transferring back, to allow synchronized transfer to alternate source.

Question 11

To calculate fuel usage during a utility outage what information would you need off of the generator?

Answer 11

Fuel consumption rate chart and the load in KW

Question 12

In the United States at what frequency does a generator run at?

Answer 12

60hz

Question 13

What parts make up the exciter circuit and what is the exciters purpose.

Answer 13

The exciter consists of the Exciter Stator, rotor and rectifier. The exciter transitions the DC output of the voltage regulator from DC to AC and back to DC to send to the main generator rotor to build a magnetic field.

Question 14

In a paralleling plant one generator is carrying more KW than another, what controls adjustment would you make.

Answer 14

Decrease the speed pot of the generator with more KW or increase the speed pots of the other generators until KW is shared and the plant speed remains 60 HZ.

Question 15

What is a PWM signal?

Answer 15

Pulse Width modulated. It is a duty cycle that is looking at the percentage of time the signal is positive vs. off.

Question 16

How does a shell and tube oil cooler work on a generator engine?

Answer 16

The shell and tube system circulates water or liquid coolant around a series of tubes to cool heated oil.

Question 17

How does a turbo charger work on a generator?

Answer 17

Exhaust drives the turbine, which is directly connected to (and powers) the compressor, which rams air into the engine.

Question 18

How does an aftercooler work?

Answer 18

An aftercooler removes heat from the compressed air coming from a supercharger before it enters an engine’s induction system. This increases efficiency and power by increasing the density of the air, making for more air molecules per cubic foot.