Precourse ILT DG

Question 1

What will auto start a DG?

Answer 1

UV or SI

Question 2

How long does the DG have to be loaded on a bus?

Answer 2

10 seconds

Question 3

What will trip a DG regardless of how it started?

Answer 3

Overspeed (660 rpm)
Generator differential current
Emergency Stop Pushbutton

Question 4

What are the pressure trips on a DG in test mode?

Answer 4

Low lube oil pressure 30 psig
Low turbocharger oil pressure 30 psig
High crankcase pressure 0.5 psig

Question 5

What is the design bases for the DG?

Answer 5

Loaded onto the bus in 10 seconds
7 days of fuel
If blackout in one unit, other unit DG can provide safe shutdown power for 4 hours

Question 6

When do Fuel Oil XFR pumps starts?

Answer 6

Both start when DG >280 rpm

One starts when low tank level 14” above centerline

Question 7

What will trip DG output breaker on UV start?

Answer 7

F Loss of field
U Underfrequency
R Reverse Power
N neutral overcurrent
D Gen Diff current
Overcurrent relay
S SAT feed BRKR lockout
E Stop PB

Question 8

What will trip the DG output breaker on an SI start?

Answer 8

Differential current

Manual

Question 9

After a DG start when does the CV pump sequence on?

Answer 9

0 seconds

Question 10

Where are the DG sequencers powered from?

Answer 10

SARA DC 111
SARB DC 112
A sequencer timer AC 111
B sequencer timer AC 114

Question 11

What are the DG ratings?

Answer 11

Continuous 5500 KW 954A
2000 hours 5935KW 1030A
2/24 6050KW 1050A

Question 12

What is the difference between droop and isochronous mode on DG?

Answer 12

In iso mode governor maintains speed constant regardless of load
In droop speed lowers as load rises

Question 13

After a DG start when does the SI pump sequence on?

Answer 13

5 seconds assuming there was an SI signal

Question 14

After a DG start, when does the RH pump start?

Answer 14

10 seconds assuming there was a SI signal

Question 15

After a DG start, when does the VC chiller sequence on?

Answer 15

15 seconds

Question 16

After a DG start when does the CC pump sequence on?

Answer 16

20 seconds

Question 17

After a DG start when does the SX pump and SX aux lube oil pump sequence on?

Answer 17

25 seconds

Question 18

After a DG start when does the A AF pump sequence on?

Answer 18

35 seconds

Question 19

After a DG start, when does the CS pump sequence on?

Answer 19

If there is a CS signal, 15-18 seconds then maintained at 40 seconds

Question 20

If the DG starts due to an ESF bus undervoltage, what mode will it start in? Will speed and voltage control be available to the operator?

Answer 20

During a UV it will start in Emergency Mode, speed and voltage will not be available since in isochronous mode

Question 21

If the DG is running and a loss of air occurs, what is the effect on the DG?

Answer 21

The only automatic trip available will be the overspeed trip

Question 22

When does the DG pre-lube pump start?

Answer 22

When DG is shutdown and speed <280 rpm, oil heaters cycle on at 120F

Question 23

When does the DG jacket water circulating pump start?

Answer 23

Pump and heaters cycle on/off when <280 rpm to maintain JW temp 120-130F

Question 24

What are the temperature trips on a DG in test mode?

Answer 24

Jacket water temp high 205F
Main bearing high temp 228F
Generator bearing high temp 228F
connecting rod bearing temp 197F

Question 25

What are the misc trips on a DG in test mode?

Answer 25

Engine overspeed 660rpm
EPB
Incomplete start sequence <280rpm @ 25+ seconds
Turbo charger thrust bearing failure 0.011in
SI signal

Question 26

What are the electrical trips on a DG in test mode?

Answer 26

FURNODS

loss of Field
Underfrequency
Reverse power
Neutral ground overcurrent
Overcurrent
Differential current
SAT breaker 1412 lockout

Question 27

List the interlocks necessary to manually close the DG output breaker

Answer 27

DG at rated speed and voltage
No lockouts on 1412 1413 1414
Syncscope on
Sync check satisfied (if bus energized)
C/S to close

Question 28

List the interlocks to auto close DG output breaker

Answer 28

DG at rated speed and voltage
No lockouts on 1412 1413 1414
UV on bus 2/2
1411 1412 1414 open
C/S in AT