Generator seal oil

Question 1

Purpose of two feed grooves?

Answer 1

Provide separate hydrogen side and air side seal oil systems.

Question 2

Power supplies of ASSO, HSSO, and ASSO backup pumps?

Answer 2

ASSO 134V
HSSO 134V
ASSO Backup DC123

Question 3

TO5256

Answer 3

Maintains air side seal oil pressure 12 psi above H2 pressure
Senses seal oil and generator gas pressure
Modulates open and shut to recirc oil to pump suction

Question 4

TO5264 turbine oil backup valve

Answer 4

Auto opens at 8psid to supply turbine oil or bearing oil pressure

Question 5

Sequence of events ordered by decreasing pressure.

Answer 5

12psid Normal setpoint maintained by air side pump recirc
8psid opens supply from main turbine oil
5psid auto starts ASSO backup pump (DC power)
Bearing oil pump can maintain 2 psig above atmosphere

Question 6

Loss of HSO pressure

Answer 6

The loss of pressure on the hydrogen side of the seal causes large quantities of ASSO to flow to the defoaming tanks. The air and moisture dissolved in the oil will come out of solution in the defoaming tanks, lowering gas purity. When operating with the hydrogen side pump off, purity requirements are lowered to 90%.
The ASSO in the defoaming tanks will go the the hydrogen side drain regulator and be returned to their side via the drain valve, TO 5321.

Question 7

Vapor extractor information

Answer 7

Removes hydrogen from loop seal tank. Failure requires repair within 1.5 to 2 hours or unit S/D directed by procedure.
133V power supply