EDG Controls and Protections

Question 1

EDG Trips

3
5**Defeated by Trips Defeat Switch

Answer 1

• Manual
  * Trips Fuel Racks
• Over-speed: 1040 RPM
  * Trips fuel racks
• 10 Second Over-Crank: Less than 200RPM in 10 seconds (From LSR)
  * Shuts the Air Start Valves
  * EDG will only try to auto-start once, EDG will have to be locally started after problem corrected.
• Start Failure **: Less than 200RPM in 10 seconds (From LSR)
  * Energizes the Governor S/D solenoid which will set the fuel racks to 0 (close)

-Engine Running Trips :
* Enabled 20 seconds after start by ERR
*Energizes the Governor S/D solenoid which will set the fuel racks to 0 (close)
A) High Crankcase Pressure- +0.5” H2O
B) Low Lube Oil Pressure- 18psig
C) Low Jacket Water Pressure- 9psig
D) High Jacket Water Temperature**- 205F

Question 2

Generator Trips: (Opens the output breaker)

Answer 2

• Reverse Power: Prevents motorizing the generator and possibly damaging the diesel.
• Over Power: prevents damage to the generator if there is a fault in the electrical system.
• Over Current: Dual indication on breaker and will lock in on APP-010-A1

Question 3

EDG Room Fire Suppression System Actuation:

Answer 3

• If a fire suppression system for the EDG Room actuates, the following occur automatically:
  * Secures associated Room Supply and exhaust fans
  * Secures associated DFO Pump
  * Closed supply and exhaust dampers to room.

-EDG will have to be declared inoperable by ITS due to no room cooling or fuel oil available.

Question 4

LSR (Low Speed Relay)

RPM
11 actions

Answer 4

• Energized at 200RPM
• Performs the following actions:
  • Stops the pre-lube oil pump, standby oil pumps and oil heater.
  • Stops the standby coolant pump
  • Stops the jacket water heater.
  • Energizes the Exp tank level control so water can be added as level requires.
  • Shuts the air start valves
  • Flashes the generator field
  • Opens the service water TCV’s
  • Deactivates the 10 second timer for Start Failure/Over-Crank Trips. (TD2)
  • Energizes the RED EDG running light

Question 5

ERR (Engine Running Relay)

RPM
4 actions

Answer 5

-Energized at 810 RPM

• Performs the following actions:
  
  • Starts the EDG Room exhaust fan and supply fan.
  • Activates the 20 second timer delay for trips. (TD3)
  • Energizes the Engine Run-hour Meter
  • De-energizes the GREEN EDG stop light

Question 6

Appendix R switches:
How many?
Normal position?
Why?

Answer 6

• 4 total on RTGB
• 2 for each E-Bus (Supply breakers 18B, 17B E1, and supply breakers 28b, 27B E2)
• 2 EDG output breakers, and 2 E-Bus normal supply breakers
• Remove control power to breaker controls at the Generator Control Panel
• Normally in isolate on RTGB