Term
| Function of Main Generator |
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Definition
| Generate electrical power from the shaft power of the steam turbine and properly control it for useful output of desired voltages |
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Term
| Power supply to main transformer coolers feeder B |
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Definition
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Term
| Power supply to main transformer coolers feeder A |
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Definition
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Term
| Voltage rating for main generator |
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Definition
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Term
| Total power rating for main generator (MVA) |
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Definition
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Term
| (Stator) Current rating for main generator |
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Definition
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Term
| Field Current rating for main generator |
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Definition
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Term
| How is rotor temperature determined? |
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Definition
| Temperature recorder on C-31 in control room that senses field voltage and field amps and automatically computes temperature from the field resistance. |
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Term
| What is the job of the voltage regulator? |
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Definition
| To sense the output voltage of the main generator and control the Exciter field current, which ultimately controls Main Generator output voltage. |
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Term
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Definition
| Exciter is air cooled with a closed ventilating system, which includes an air-to-water heat exchanger located in the upper portion of the Exciter frame. |
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Term
| Describe main transformer cooling |
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Definition
| 13 forced oil-air heat exchangers. |
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Term
| Main transformer cooler power supplies |
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Definition
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Term
| When do main transformer coolers automatically start? |
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Definition
| When field breaker is closed. |
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Term
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Definition
| Transmit 22 KV output from main generator bushings to main transformer. |
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Term
| Current ratings for isophase bus (with and without cooling) |
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Definition
| With cooling: 18,700 Amps (recall: generator is only rated 17,436 Amps); Without cooling: 10,500 Amps. |
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Term
| Purpose of removable link in each bus bar beneath the Generator |
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Definition
| Removal of links allows main transformer to be energized when generator is not in service. |
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Term
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Definition
345 KV breakers used to connect the main generator to the sub-yard. NOTE: either breaker is capable of carrying full output of the generator. |
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Term
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Definition
Generator neutral overvoltage (for ground on 22 KV circuit); Generator transformer sudden pressure (for fault in transformer); Generator differential relays (for fault in generator); Generator transformer and generator differential relays (for fault in generator, transformer or isophase bus); 345 KV breaker failure (8N4 and 8N5 fail to trip open... located in substation control house); Fault in main transformer or 345 KV lines between transformer and 8N4 and 8N5; Generator overcurrent; Over excitation, loss of excitation and V/Hz; Manual (C-08).
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Term
| Automatic actions upon generator lockout |
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Definition
If main transformer disconnects are closed, then four lockout relays in substation control house operate to trip and lock out 8N4 and 8N5; Field breaker trips and locks out; Turbine master trip solenoid operates; Trips turbine lockout relay (286T) which operates master trip solenoid 1
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Term
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Definition
Moisture separator tank high level; Turbine thrust wear detection; Reactor high water level; Turbine exhaust hood high temperature; Low vacuum; Generator negative sequence; Generator loss of field; Generator lockout; Loss of stator cooling
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Term
| Automatic actions upon turbine lockout |
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Definition
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Term
| Biggest concern when prime mover loses its power |
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Definition
| Heating of the turbine blades due to generator motoring. |
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Term
| When does anti-motoring trip? |
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Definition
| If turbine stop valves go closed whenever main transformer disconnects are closed and 8N4 and/or 8N5 are closed. |
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Term
| Automatic actions upon Anti-motoring relay trip |
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Definition
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Term
| Function of Voltage Regulator protective functions |
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Definition
| Prevent damage to main generator and main transformer |
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Term
| Voltage regulator protective features |
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Definition
Loss of Excitation; Generator Field Current Online/Offline Over Excitation; Under Excitation Limiter; Manual Restrictive Limiter; Over Voltage; Volts/Hz; Power system stabilizer.
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Term
| Generator underfrequency setpoint |
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Definition
| 58.5 Hz (two-out-of-three logic) |
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Term
| Reason for underfrequency protection |
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Definition
| Limitations imposed by turbine buckets (natural resonance). |
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Term
| Stator temperature limits on startup |
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Definition
| "If stator temperature is below 20 degrees C, prewarm to this temperature at a rate not to exceed 10 degrees C per hour before going beyond 1500 rpm. This can be done by closing the field breaker with the voltage regulator in auto until both rotor and stator temperatures are above 20 degrees C." |
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Term
| Purpose of Volts/Hz limiter |
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Definition
| Prevents operation in areas of capability curve which could damage generator. |
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Term
| Generator upper and lower voltage limits |
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Definition
| Max: 23.1 KV; Min: 20.9 KV (plus or minus 5%) |
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Term
| Isophase bus lead max current (with and without cooling) |
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Definition
With cooling: 18,700 Amps (recall: generator is only rated 17,436 Amps); Without cooling: 10,500 Amps.
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Term
| Power supply to Voltage regulator controllers |
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Definition
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Term
| Power supply Gen and Aux Power Bench |
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Definition
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Term
| Power supply to Isophase Bus Blower |
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Definition
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