LOT 201.35 Non-Class DGs

Question 1

• LOT 201.35 Non-Class DGs*
• • *

How are the Non-Class DGs started?

Answer 1

• BOP / NTF / LTG:*
• *Two 24 VDC Electric Starting Motors**
• Rated for 10 Starts*
• Flex:*
• *One 24 VDC Electric Starting Motors**
• TSC:*
• *Air Driven Starting Motor (90 - 120 psig)**

Question 2

• LOT 201.35 Non-Class DGs*
• • *

Where are the Non-Class DGs physically located?

Answer 2

• TSC DGs:*
• *N of TB enclosed in Trump Wall**
• BOP DGs:*
• *31’ TB SE side**
• Flex DGs:*
• *MAB Roof**
• Lighting DGs:*
• *S Side between Units**
• NTF DG:*
• *W of NTF**

Question 3

• LOT 201.35 Non-Class DGs*
• • *

What prevents synchronizing a Non-Class DG onto a live bus?

Answer 3

Output CBs ELECTRICALLY interlocked to prevent being closed while normal bus feed is closed

Question 4

• LOT 201.35 Non-Class DGs*
• • *

What trips the BOP / NTF / LTG DGs?

Answer 4

BOP / NTF / LTG:

• *Engine Overspeed**
• ≈ 115% (2073 rpm)*
• *Lube Oil Pressure - Low**
• (20 psig)*
• *Cooling Water Temperature - High**
• (210 ˚F)*
• *Generator Overcurrent**
• (2400 amps)*
• *Generator Volts/Hertz NOT within Limits**
• (2.2 V/Hz for greater than 15 seconds)*
• N/A for Unit 2 BOP AND NTF*
• *Engine Over crank [Lockout]**
• (3 cycles)*

Ground Fault (NTF ONLY)

Question 5

• LOT 201.35 Non-Class DGs*
• • *

What trips the Flex DGs?

Answer 5

• *Engine Overspeed**
• (1980 rpm)*
• *Lube Oil Pressure - Low**
• (73 psig)*
• *Cooling Water Temperature - High**
• (215°F)*
• *Coolant Level - Low**
• (sensor in upper portion of radiator)*
• *Engine Overcrank [Lockout]**
• (3 cycles)*

Question 6

• LOT 201.35 Non-Class DGs*
• • *

What loads does the Flex diesel supply?

Answer 6

• Normal:*
• *Flex RCS M/U Pumps**
• *Flex S/G M/U Pumps**
• *Flex SFP M/U Pumps**
• Backup:*
• *CVCS PDP**
• *RCB Equipment Hatch Hoist**
• B/U to TSC DG*
• *480V ESF LC and MCC**

Supplies 480V LC DP1000

480 V / 1000 kW / 1800 RPM

• Note:*
• Within 8 hours following an Extended Loss of AC Power (ELAP) the FLEX Diesel Generator will be running providing power to support SG make-up, RCS make-up, SFP make-up, and other functions in support of STP’s FLEX strategies.*

Question 7

• LOT 201.35 Non-Class DGs*
• • *

What trips the TSC DGs?

Answer 7

• *Engine Overspeed**
• ≈ 110% (1980 rpm)*
• *Lube Oil Pressure - Low**
• (30 psig)*
• *Cooling Water Temperature - High**
• (210 ˚F)*
• *Loss of Excitation**
• (≥ 2 sec)*
• *Overcurrent**
• (300 Amps)*

Phase Differential [Lockout]

• *Engine Over crank [Lockout]**
• (3 cycles)*

Question 8

• LOT 201.35 Non-Class DGs*
• • *

What loads does the NTF DG supply?

Answer 8

Motor-Driven Fire Pump House

NTF Simulator

Feeds 480V 12N

BOP, NTF, and Security LTG DGs: 480 VAC / 700 KW / 1800 RPM

Question 9

• LOT 201.35 Non-Class DGs*
• • *

What loads does the Security Lighting DG supply?

Answer 9

Security LTG

EAB UPS

Intake Structure LTG

Feeds 480V 12K3

BOP, NTF, and Security LTG DGs: 480 VAC / 700 KW / 1800 RPM

• Note:*
• Auto Starts on loss of voltage, comes up to speed and closes breaker in 15 seconds*

Question 10

• LOT 201.35 Non-Class DGs*
• • *

What loads does the BOP diesel supply?

Answer 10

Battery Chargers 125V/250V

IA Compressor 14

Turning gears for MFPs and Main Turbine

Bearing Oil Lift Pump

Air Side Seal Oil Pump

Feeds MCC 1G5

BOP, NTF, and Security LTG DGs: 480 VAC / 700 KW / 1800 RPM

• Note:*
• BOP DG Fuel Tank will last 60 mins
• Auto Starts on loss of voltage, comes up to speed and closes breaker in 15 seconds

Question 11

• LOT 201.35 Non-Class DGs*
• • *

When will the Non-Class DGs trip on overspeed?

Answer 11

• BOP / NTF / LTG:*
• *2073 RPM**
• ≈115% of 1800 RPM*
• TSC / Flex:*
• *1980 RPM**
• 110% of 1800 RPM*

• Note:*
• TSC DG also equiped with device to prevent overloading TSC DG during S/U. (Puts TDs on when loads can be started)*

Question 12

• LOT 201.35 Non-Class DGs*
• • *

What control room indications are their for the Non-Class DGs?

Answer 12

• BOP / LTG / TSC:*
• *CP003 (Trouble alarms)**
• Flex / NTF:*
• *None**

Question 13

• LOT 201.35 Non-Class DGs*
• • *

What loads does the TSC DG supply?

Answer 13

ICS Computer

CVCS PDP

FHB IVC LTG XFMRs

• *RCB Equipment Hatch Hoist**
• Flex DG provides B/U power*

Emergency XFMR cooling fans

Feeds 4.16 kV LC 1W1 → MCC 1G8

4. 16 kV / 1200 kW / 1800 RPM
   * * *

• Note:*
• Auto Starts on loss of voltage, comes up to speed and closes breaker in 15 seconds*

Question 14

• LOT 201.35 Non-Class DGs*
• • *

What auto starts the Non-Class DGs?

Answer 14

• BOP / NTF / LTG / TSC:*
• *Bus Undervoltage**
• 2 sec from UV to breaker shutting*
• Auto start blocked if feeder breaker tripped on Overcurrent*
• Flex:*
• *No auto starts**

BOP / NTF / LTG / TSC:

• Switch has 3 positions - Hand / OFF / AUTO
  
  • Auto allows UV start
  • OFF prevents start (TSC 5 min C/D)
  • Hand starts DG in manual (TSC requires pressing start button in addition to Hand)

• Note:*
• Pushing the Manual Auto to Bypass Pushbutton allows going from Hand to Auto w/o shutting down DG.*

Question 15

• LOT 201.35 Non-Class DGs*
• • *

What are the Non-Class DG output breakers close permissives?

Answer 15

• *Normal Supply Breaker Open**
• *No overcurrent trip on supply breaker**
• *No Lockout Relays energized**
• *Mode Switch NOT in off**
• *Remote Switch NOT in PTL (TSC ONLY)**