Generator Support Systems Notes

What handswitch position places a SCW pump in standby?

"A" Reserve or "B" reserve

How must H2 trailer port deluge controls be maintained to allow actuation of the sprinkler system?

"Normal"

What is the normal conductivity of SCW?

0.1-1.5 microSiemens/cm

How is the H2 FCV from the H2 Control Cabinet 0-L-21 operated?

1. Hold the open handswitch in the MCR until the valve is fully open then release. 2. Operate from local control station

What temperature does the H2 trailer port deluge system actuate?

1. Rate of temperature rise > 12%/minute 2. Fixed temperature greater than 100 degrees F

Where does the cold gas leaving the H2 cooler go?

1. Stator Iron Passageway 2. Rotor and exciter endof the generator 3. Parallel rings and lead connectors 4. Radial passageways through stator into rotor ventilation gaps.

What two paths can air side seal oil take from the pumps?

1. Through the air side seal oil cooler, filters, and generator air side of the gland ring. 2. Through PCV-35-24 back to the suction of the pump.

What is SCW filter high dP alarm setpoint?

10 psid

What tells operators that the DC air side seal oil pump is running?

10 psid across the DC pump brings in a MCR alarm.

What temperature is the H2 cold gas maintained at?

100-105 degrees F

What is generator H2 supply high pressure alarm?

110 psig

What is pressure reduced to at the H2 trailer port?

110 psig

What is maximum H2 temperature in generator?

115 degrees F

What is H2 side seal oil pump discharge releif valve setting?

115 to 125 psig.

What temperature does the air side seal oil HX maintain?

115-120 psig

Which pressure regulator does the DC Seal Oil Backup Pump go through?

12 psi regulator

What pressure is air side seal oil maintained to?

12 psig above generator pressure

What is setpoint of releif valves in the trailer port discharge header?

125 psig.

What is high temperature turbine trip from Stator cooling water?

140 degrees F (90 degrees C) for 45 seconds at 15% power

What is H2 pressure on top of SCW tank?

2 psig

What must generator gas pressure be reduced to if the eductor is supplying air side seal oil?

2 psig

What is the normal source of H2?

2 trailers at the H2 trailer port.

What is H2 trailer pressure?

2400 psig

What is normal SCW Pump pressure?

28 psid on Unit 1 25 psid on Unit 2

What is the minimum seal oil pressure above generator pressure to maintain a seal?

3 psig

How long is the dessicant bed regenerated?

4 hours heat up. 4 hours cool down.

What is SCW tank high pressure alarm?

4 psig

What is flamable concentration of hydrogen in air?

4-75%

What is the power supply for the vapor extractor?

480V TB MOV Bd 1A.

What is the power supply for the Air Side Seal Oil Pump?

480V Unit Bd 1A (2A)

What is the power supply for the Stator Cooling Water Pumps?

480V Unit Boards

What is the auto start pressure for the air side seal oil backup pump (DC)? What else happens?

5 psig above generator gas pressure.

What is the pressure to air side seal oil from the LP supply?

5-15 psig

Where is SCW Skid?

685'

Where is H2 dryer?

706

Where is standby selector switch for SCW pumps?

706'

What is maximum generator pressure?

75 psig

What is pressure reduced to before entering the generator?

75 psig

What pressure does the secondary H2 control cabinet 0-L-18 regulate to?

75 psig

What is one SCW Heat Exchanger capable of cooling?

75% load with temperature out < 60 degrees F.

What pressure does the backup pressure PCV-35-246 maintain?

8 psig oil above generator pressure

What are H2 generator pressure alarms?

80 and 66 psig

What is temperature range for outlet of H2 side HX?

80-120 degrees F.

What is low Main oil system supply to Air Side Seal oil alarm?

85 psig

What are Stator Cooling Water Pump Trips?

87GX on Main Generator Motor Protection

What is alarm setpoint for air side seal oil?

9 psid

What is normal flow rate through SCW demineralizers?

< 50 GPM

What temperature difference between air side seal oil and H2 side seal oil is best?

<2 degrees F

What conductivity in Stator Cooling Water requires that the turbine be shut down?

>9.5 microSiemens/cm

How is Main oil system to Air Side Seal oil controlled?

A PCV-35-44 lowers pressure from 300 psig to 125 psig.

What are 2 pumps for Air Side Seal Oil?

AC and DC pumps

What other 2 functions does the Generator Bearing Loop Seal Tank provide?

Accepts drains from generator bearings and air side seal oil drains and provides a reservoir for air side seal oil supply.

How can H2 be vented from the generator?

Air Operated Valve FCV-35-33 from the MCR or manual valve on 706

What are sources of air side seal oil?

Air Side Seal Oil Skid (AC or DC) Main Turbine Lube Oil Main Turbine Lube Oil Bearing Header

What is possible if the generator is operated without H2 side seal oil? What might be required?

Air intrusion into the H2. Purge generator a small amount daily to increase hydrogen purity.

What is the purpose of defoaming tank?

Allow H2 to vent back to generator before returning to pump suction.

What does the Secondary H2 Control cabinet 0-L-18 supply hydrogen to?

Aux Building H2 loads. (VCT)

What is the LP air side seal oil pressure source?

Bearing Lube oil header from MTOT eductor. MOP > 1200 RPM TGOP < 1200 RPM

Why hydrogen?

Better heat removal than air allows larger capacity machine.

What is the purpose of the Stator Cooling Water System?

Circulate high purity water via corrosion resistant piping and components through each stator coil hollow conductor to remove heat due to stator coil losses.

How do the H2 FCV's fail on loss of air or power?

Closed

What is disabled automatic SCW makeup?

Condensate

How are the stator cooling water filters maintained full?

Continuous vent on top of the filter housings with approximately 10 GPM back to the housing.

How is conductivity of Stator Cooling Water Maintained?

Continuously cycing a portion of the flow through the system through the demins.

What is makeup for SCW?

Demin Water

What is the importancce of preventing H2 release?

Fire Hazard

How is leakage detected in the H2 cooler/generator?

Float switches on drains from the generator.

What are the sources of generator heat?

Friction (Windage) Resistance of the Generator windings (I^2R) Hysteresis

Where does the vapor extractor remove air from?

Generator Bearing Loop Seal Tank

Where does the suction for the Air Side Seal Oil Pumps come from?

Generator Bearing Oil Drain Line Reservoir.

How is generator H2 Purity monitored?

Generator Purity meter on 706'

Given the following plant conditions and information: - Unit 2 is at 16% power and a startup to 100% power is in progress. - "GEN STATOR COOL SYS FAILURE" alarm just came in on panel 2-XA-M1-A. For information: - Turbine generator trips from the stator cooling system have a 15% built in load reference. Which ONE (1) of the following describes the source of the load reference signal?

Generator full load amps.

What provides suction pressure to the H2 Seal Oil Pump?

H2 Side Seal Oil Float Chamber

Where do H2 seals drain to?

H2 defoaming tank.

What 2 H2 monitoring indications are in the MCR?

H2/O2/CO2 purity and H2 pressure.

What is used to put out a fire at the H2 trailer port?

HPFP deluge system.

When is maximum air side seal oil temperature exceeded.

Hot temperatures in the summer.

What is cover gas on SCW tank? Why?

Hydrogen. Keep O2 out to minimize oxidation and maintain water purity

What is internal to the SCW tank?

Internal baffle to reduce waves

What is link for the CO2 system purge?

J Link

What must be installed to purge the generator with H2?

Link "A"

What are SCW Pressure alarms?

Low Flow: 23.5 psid decreasing or 10 psid across filter High Pressure: 35 psid across pump

What are H2 purity alarm setpoints?

Low: 90% High: 100%

Where does oil from the loop seal drain to?

MTOT.

Where does secondary H2 control cabinet 0-L-21 provide flow?

Main Generator and other secondary loads

What is the high pressure backup to air side seal oil?

Main oil system. MOP > 1200 RPM SOBP < 1200 RPM

What can be done if the B/U Pressure Control Valve fails?

Manual bypass valve around the PCV (Green Handled Vavle) .

Can the H2 Side Regulator Tank level be manually adjusted? How?

Manual valves are provided to "jack" the LCV open for manual adjustment.

How is Generator supply FCV-35-32 operated?

Manually open from the Secondary Station

How does the generator supply FCV-35-32 fail?

Open

How is Air side seal oil HX temperature maintained?

Outlet RCW TCV-24-73

How is H2 side seal oil pressure controlled?

Pressure equalizing valves (PCV-35-254, 255) which maintains pressure to + or - 2 psig to the air side seal oil.

What is the purpose of the H2 Seal Oil System?

Prevent H2 fom escaping the generator without introducing an excessive amount of air or moisture.

What is the purpose of the loop seal on the Generator Bearing Oil Drain?

Prevent H2 from escaping into the main oil tank upon failure of the H2 seals.

What is the purpose of the H2 side drain regulator tank?

Provide suction pressure to the H2 side seal oil pump.

What is the purpose of the SCW Water Tank?

Provide surge protection for SCW

What is cooling medium for H2 coolers?

RCW

What isthe overpressure protection on the SCW tank air space?

Relief valve set at 5 psig.

What is the purpose of the H2 Cooling System

Remove heat from the generator rotor and stator generated while reducing windage.

What might excessive SCW exhaust flow on the totalizer indicate?

SCW tube leak in generator or pressure regulator malfunction.

What circulates H2 through the generator?

Six stage blowers on either end of the generator which pull air out and circulate it throug the cooler.

What pressure does the secondary control cabinet 0-L-21 control pressure to?

Stage 1: 100 psig

How is level maintained in the defoaming tanks?

Standpipe inside tank that overflows to the H2 Side Receiving Tank.

Where does "H" link provide H2 flow?

Stator Cooling water tank

What is the location of the vapor extractor?

TB 706

What is H2 dryer power supply?

TB MOV Bd 1A (2A)

What is the power supply for the H2 Side Seal oil pump?

TB Vent Bd. B.

What keeps the SCW heat exchangers full?

They are continuously vented back to SCW tank. 5-10 GPM.

How is Generator purged?

To remove H2, purge with CO2 then air. To place H2 in the GEN, purge with air with CO2 then H2.

Where does excessive level in the H2 side reguraltor tank go?

To the suction of the air side seal oil pumps.

What prevents oil vapor circulation between defoaming tanks?

Trap between them in common drain line.

Where do SCW trips input?

Turbine trip bus.

What pressure does PCV-35-241 maintain on the generator bearings?

Unit 1: 12-15 psig above generator gas pressure on turning gear and 15-18 psig above generator gas pressure at full rated speed. Unit 2: 12-15 psig above generator gas pressure at all times.

What is SCW Turbine Trip?

Unit 1: 19 psid on 2/3 PS for 45 seconds at > 15% rated current. Unit 2: 15.5 psid on 2/3 for 45 seconds at > 15% rated current

What is power supply for DC Air side seal oil backup pump?

Unit 1: 250VDC Battery Bd. 1 Alternate. Battery 2 Unit 2: 250V DC Battery Bd. 2 Alternate: Battery 1

What is the location of the secondary H2 control cabinet 0-L-21?

West side of TB in yard.

When should the H2 vent to atmosphere not be opened?

When the H2 supply to the generator is also open

Can the generator be operated without H2 side seal oil?

Yes

What will start the standby Stator Cooling Water pump?

dp across the running pump less than 20 psid