Control Oil (Main Turbine) (CO)

Question 1

At what pressure will the standby control oil pump autostart?

Answer 1

The standby Control Oil Pump will automatically start if the hydraulic fluid pressure in the system
drops to 1300 psig.

Question 2

What is the position of CO Flow Control Valve 27? How is this position maintained?

Answer 2

FCV-27 is an adjustable flow control valve. The valve is manually positioned according to the flow desired. The valve is Key locked and the key is located in the control room. The valve is used to divert a controlled portion of the hydraulic fluid to be cleaned up and thereby maintain fluid purity.

Question 3

How does the Control Oil system cause a turbine trip?

Answer 3

A low Control Oil Header pressure of 1100 psig as sensed by two out of three pressure switches (CON-PSL1A/B/C) will trip the Main Turbine.