Condensate (CD)

Question 1

How do the VACUUM BREAKER
VALVES HV-45A/45B/45C fail?

Answer 1

Condenser Vacuum Breakers (3)
• Rapid slowdown of turbine by breaking vacuum. (Do NOT open until < 1200 rpm)
• Water seal on the outlet of the valve to prevent in-leakage. Manually filled from Condensate Service Header.
• One MCR HS controls all 3. Dual indication unless all valves closed or open.
• AOVs (Fail closed)

Question 2

What will cause the Condensate Pumps (CDN-P01A/B/C) to trip?

Answer 2

Each pump will automatically trip on any of the following conditions:
* Low flow (<3,600 gpmfor greater than 45 seconds)
* Condenser hotwell level in the related half is 30” (The Hotwell Lo-Lo level alarm setpoint is 34” and if it is reached, the alarm comes in. If level continues to lower to 30”, a trip will occur. Condensate pump B, CDN-P01B, will trip at 30” in either hotwell half if its related suction valve is full open)
* 4.16 kV Bus Undervoltage (NBN-S01 or NBN-S02)
* Lockout Relay (This relay is tripped by phase overcurrent, differential current, phaseunbalance or a ground fault)
* CDN-P01B requires at least one of its suction valves to be full open in order to operate thepump

Question 3

The Condensate pump motor lube oil coolers are cooled by ?

Answer 3

Turbine Cooling Water (TC)

Question 4

What is the suction source for the Condensate Pumps (CDN-P01A/B/C) ?

Answer 4

Condensate Pumps
* 50 % capacity pumps
o A/B pump NBN-S01
o C pump NBN-S02
* A Pump suction: 2A, 2B, 2C hotwells
* C Pump suction: 1A, 1B, 1C hotwells