Circ Water

Question 1

Safety features of Circ water system to protect Emergency diesel generator?

Answer 1

• installed flood door between condensers and EDG - float switch to Trip CWP if condenser pit floods to certain level

Question 2

P.S. To CWP Capacity Head

Answer 2

1-1. D 1-2. E 433,500 gpm / pump 96.5’ head

Question 3

What must be met to start CWP?

Preferred?

Answer 3

• CWP bkr open > 5 min (bypass available)
• CWP rev rotation < 5 rpm
• ICW pump Press > 24.5 # (only on start)
• started w/in 45 sec of releasing jacking device

Question 4

CWP trips (6)

Answer 4

• Motor O.C.
• Motor differential
• Bus differential
• Bus UV (4 sec time delay, for bus xfr)
• Cond pit hi lvl (81.25’)
• 12 kv bus xfr (if xfr Trip cut in)

Question 5

What provides seal injection for CWP’s? How many shaft seals are there?

Answer 5

Discharge of CWP 3 Mech- normal seal Inflatable- outage seal Packing- b/u to both

Question 6

Purpose of CWP jacking device

Answer 6

Lift the motor and pump, allow oil to enter between shoes and thrust collar. Used before starting CWP

Question 7

Purpose of CWP disch float valves

Answer 7

• Allow venting of CW tunnels upon filling (start) - break vacuum of CW tunnels upon draining (stop)

Question 8

Describe operation of Condenser water box vent valves when in auto

Answer 8

• Open for 3 min following CWP start (vent air) then close - open 1.5 sec after CWP trip (backfill air)

Question 9

What is maximum daily average that CW can raise outfall?

Answer 9

22 deg

Question 10

What does ICW do? Describe ICW

Answer 10

Cools CWP motor (air cooled)(ICW cools radiator) and CWP bearing oil One head tank, two pumps, two hx, chem injection system

Question 11

Describe auto reclose feature on CWP’s

(include example positions of switches)

Answer 11

Due to voltage limitations when an auto bus xfr occurs only one CWP should be running

• CWP 1-1
  
  • fast auto xfr trip rco-> cut out (fast xfr stays on)
  • auto reclose -> cut in (restart if cond met)
  • slow auto xfr trip rco-> cut out (slow xfr stays on)
• CWP 1-2
  
  • fast auto xfr trip rco-> cut in (fast xfr trips)
  • slow auto xfr trip rco-> cut in (slow xfr trips)
  • auto reclose-> cut out (stays tripped)

Question 12

What is normally aligned to CWP that has auto reclose cut in?

Answer 12

SCW, because if have xfr, you want to have SCW to cool turbine components

Question 13

What conditions must be met for auto reclose to work?

Answer 13

• bkr open < 1.5 sec
• CWP voltage < 3 kV (25% of 12 kV)
• rev rotation < 5 rpm
• S/U bkr closed
• No 12 kV UV Trip
• No CWP O.C. or diff relay tripped