AP-7 (Degraded condensor)

Question 1

AP-7

What are the different sections of Degraded Condenser?

Answer 1

A - loss of condenser vacuum

B - Condenser fouling

C - Traveling screen problem

Question 2

What is the maximum condenser pressure allowed before the turbine will trip (AP-7, attch 2)

Answer 2

• full load - 10.2 “ hg abs
• 600 Mw - 7.2 “ hg abs

Question 3

In AP-7, section A (loss vaccum), what are the Rx trip criteria?

Answer 3

• Pressure above limit (attch 2) and > P-9
• no CWP
• abnormal CWP amps (if only one pump on)

Question 4

AP-7 (degraded condenser)

In section B (condenser fouling), what are the conditions that warrent ramping the unit to remove affected CWP from service?

Answer 4

• any D/P > 10 psid and rising rapidly
• all four D/P > 10 psid or approaching, with no change in ocean conditions
• any D/P approaching 13 psid

Question 5

if dealing with a degraded condensor condition, what is the “caution” asscociated with securing a CWP?

Answer 5

the backflow from shutdown of an affected CWP could cause a large rise in loading on the screens of the CWPs still in service. Screens fro the least affected pumps should be in high speed prior to the CWP shutdown.

Question 6

AP-7 (section C)

While in traveling screen problems what parameters will direct you to Trip Rx?

Answer 6

Screen d/p > 70 “

CWP amps not normal

additional conditions / actions

• Pwr > 25%
• trip CWP
• close MSIV’s
• adjust 10% stm dmps-> current P _s/g