ED1 – Emergency Diesel Generators

*EDG Emergency Start Signals:
Emergency Start Signals:

– BO

– SI

– SIS Auto Lockout

– CR Emergency Start H/S

– Local Emergency Start H/S w/ RLMS in Local

*EDG Normal Start Signals:
Normal Start Signals:

– CR Normal Starts

– Local Normal Start H/S w/ RLMS in Local

*How does air receiver tank pressure affect EDG Emergency Start capability?
– Engine will rotate with air until > 200 rpm or pressure in both receivers < 150#- Emergency start blocked if air receivers < 150#

*What automatic protective features does EDG have after Emergency Start?
– Automatic protective features are disabled except *mechanical overspeed* and *86-1 lockout*

*How are full automatic protective features restored to EDG after Remote Manual Emergency Start?
– Full Protection Restoration from Remote Manual Emergency Start

– RLMS to LOCAL

– CR DG Emergency HS to STOP

– RLMS to REM

Describe the following Voltage Regulator Modes of Operation:

– Automatic Voltage Regulation (AVR)

– Exciter Current Regulation (ECR)

– Magnetics

Voltage Regulator Modes of Operation

– *Automatic Voltage Regulation* (AVR) – will maintain voltage within 0.5% of setpoint, normal mode of operation. If in isochronous mode and high voltage (7100 Volts) occurs, then AVR replaced with Magnetics.

– *Exciter Current Regulation* (ECR) – voltage must be controlled manually for changing loads.

– *Magnetics* – will maintain voltage within 4.8% of no load voltage, if the AVR trips during normal operation as indicated by the AVR Trip light being illuminated, the D/G will trip.

– *Anytime voltage control is not in AVR then the EDG is inoperable!*

FOST TS Minimum Volume in Modes 1-4? Modes 5-6?
FOST TS Minimum Volume

– *Modes 1-4* FO Storage Tank mini volume *86,000 gals*

– *Modes 5-6* FO Storage Tank Min Volume *75,000 gals*

*TS Minimum Air Receiver Tank Pressure? Admin Limit?
TS Minimum Air Receiver Tank Pressure *≥ 180 #*

Admin limit is *184#*

TS FODT Minimum Volume?
TS FODT Minimum Volume is *1440 gals* (37″ or ~ 62%)

– EDG will actually run for ~2.8 hours, based on 8-12 gpm of fuel use

What EDG components receive AL on SI?
The following receive AL on SI:

1) Prelube Pump

2) Aux LO Pump

3) Aux JW Pump

4) Keep Warm Pump

5) Waste Drip Tank Pump

6) FO Booster Pump

7) Air Compressors

What EDG components receive OL on BO?
The following receive OL on BO:

1) Prelube Pump

2) Aux LO Pump

3) Aux JW Pump

4) Air Compressors/Dryers

EDG Trips? (18)
EDG Trips:

1) Hi bearing Temperature 228°F

2) Return Line LO Temperature 200°F

3) LO Pressure at Turbochargers 15# (Left Bank or Right Bank) *

4) LO Pressure at header 30# *

5) Hi Vibration on a Turbocharger (Left or Right Bank)*

6) Engine Hi Vibration *

7) Crankcase Hi pressure 3# *

8) JW Return 200°F *

9) Reverse Power (86-2)

10) Loss of Field (86-2)

11) Negative Sequence (86-2)

12) Time Overcurrent (86-2)

13) Ground Overcurrent (86-2)

14) Over excitation (86-2)

15) Neutral Voltage (Gen gnd) (86-2)

16) High Gen Bearing Temp > 190°F (86-2)

17) Phase to Phase Fault *(86-1)*

*18) Mechanical Overspeed (115%), must be manually reset at overspeed pivot lever.

** 60 sec time delay after normal start before active.*

*DG Output Breaker Trips (with RLMS in Remote)?
DG Output Breaker Trips (RLMS in Remote)

1) SI and either normal or alternate feeder breaker are closed.

2) 86-2 for the bus or generator without an emergency start.

3) 86-1

4) Engine shutoff cylinders are pressurized to shutdown the engine

5) Breaker HS to TRIP or PULLOUT

*DG Output Breaker Trips (From HSP)?
DG Output Breaker Trips (From HSP)

1) Breaker control is transferred with normal or alternate feeder breaker closed.

2) 86-2 for the bus or generator without an emergency start.

3) 86-1

4) Engine shutoff cylinders are pressurized to shutdown the engine

5) Breaker HS to TRIP or PULLOUT

*6) If breaker is tripped from the RSP must transfer control back to the CR and then back before the breaker can be reclosed from the RSP, because of anti-pumping circuit

*How does loss of uEC1 or uEC2 affect EDG’s?
1) A DG 86-2 lockout relay (loss of uEC1 or uEC2) will prevent diesel start on loss of power.

2) If diesel running due to a loss of offsite power, a loss of uEC1 or uEC2 will restore normal trips and stop the diesel due to a DG 86-2 lockout relay. This does not prevent an emergency start via the H/S or from SI.

*SOP limits for EDG real and reactive load?
DO NOT exceed 7 MW or 5000 KVAR per SOP

*HV-4393 & HV-4394 DG SW Return Valve Auto function?
SSW return from the EDG is normally open however it receives an open signal whenever EDG speed reaches 200 rpm

How is EDG restored after loss of air to the diesel generator pneumatic logic board?
Following a loss of air to the diesel generator pneumatic logic board, restoration of air will require reset of the EDG RUN/STOP MECHANICAL TRIP PRESSURE SWITCH.

An internal relay on the logic board will vent air until the EDG RUN/STOP MECHANICAL TRIP PRESSURE SWITCH is pushed to TRIP AND then pulled out to RUN.

Per design bases, how long must EDG be able to run?
Each EDG must be able to operate for 7 days at rated speed and voltage with full load, after which it must still retain its 10 second start and load capability.

*When do start air admission valves close after Normal Start? After Emergency Start?
• Upon normal start the start air admission valves close 5 secs after start signal or when engine speed reaches >200 rpm

• Upon emergency start the start air admission valves will not close until receiver pressure is < 150# or engine speed ≥ 200 rpm; Starting air banks are supplied from separate receivers.

When does Aux JW Pump auto start? (UΔ)
Aux JW Pump auto starts on EDG speed > 200 rpm and JW pressure ≤ 10# (≤ 7# U2)

When does Ready To Load red light illuminate?
READY TO LOAD (red): actuated when the engine speed ≥ 425 rpm with generator output voltage ≥ 6210 VAC.

*Which EDG trips are active on Emergency and Normal starts?
1) Phase to Phase Fault (86-1), will trip EDG on normal or emergency start.

2) Mechanical Overspeed (115%), will trip EDG on normal or emergency start.

*Limitations for running EDG unloaded?
The vendor recommends that unloaded operations be limited to < 5 minutes.If a diesel is operated for more than 30 minutes in an unloaded condition then the machine must be loaded to remove any unburned fuel in the exhaust system.When loaded, the diesel generator should be operated at a minimum of 3.5 MW for 60 minutes

*Normal Start Sequence
Normal Start Sequence:

1) Starting Air admission stops when engine speed >200 rpm or 5 seconds elapsed, whichever occurs first.

2) 1 second after start signal field flashing occurs and also at 200 rpm.

3) If FAST/SLOW HS in SLOW field flash occurs @ 425 rpm.

4) Ready to load solenoids energize @ 425 rpm and voltage
> 6210 VAC.

5) All protective trips enabled in the NORMAL Mode.

*Emergency Start Sequence
Emergency Start Sequence:

1) Start Air Pressure >150 psig

2) Will continue to attempt to start until >200 RPM or Air Receiver Pressure < 150 psig3) DG Protection - Engine Overspeed (517.5 rpm) - Generator Differential (86-1) - All remaining trips are defeated unless emergency start signal is removed4) Full Protection Restoration - Emergency Start DG via HS - Reset Emergency Start Signal if present - RLMS to LOCAL - DG Emergency HS to STOP - RLMS to REM

EDG TS Limits for Voltage and Frequency?
Each DG starts from standby conditions and achieves steady state voltage ≥6480 V and ≤7150 V, and frequency ≥58.8 Hz and ≤61.2 Hz.

*What happens when AVR trips while operating in Emergency Mode, and during Normal operation?
If Voltage Regulator trips while operating in EMERGENCY MODE (SI, Blackout, or Emergency Start), the generator would go into the Magnetics Mode.

If the AVR trips during normal operation as indicated by the AVR Trip light being illuminated, *the D/G will trip*.

1-01 EDG is parallelled to the grid. MVAR indicates zero. Raising EDG voltage > grid voltage will
Result in VARS out/lagging (+ VARS).

How will raising 1-01 EDG speed affect indication
a) if the EDG is parallelled?
b) if the EDG is carrying the bus
a) if parallelled, MW will increase
b) if carrying the bus, speed (frequency) will increase.

*Describe operation of Fuel Oil Transfer Pumps during engine operation…
Lead pump will start on Day Tank low level and shutoff on Day Tank high level
Lag pump will start on Day Tank low low level and shutoff on Day tank high level

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