Main Generator

Question 1

Generator Limitations

Answer 1

Air Cooled (5#) - 126,000 (.88pf) KVA (120,000 (.85) KVA
No SWC Flow (1hr Limit) - 240,000 KVA w/60# H2
One H2 Cooler OOS - 800,000 KVA
1/2 H2 Cooler OOS - Full load with air temp 86-118degF
One SWC Cooler OOS - 924,000 KVA w/PSW <85degF & >3200gpm
Iso-phase cooling lost - 14,000 (12,800) Amps
Self-Cooled - 6466 Amps

Question 2

Shaft Voltage Monitor

Answer 2

Prevents damage to bearings due to build up of static electricity onto rotating element

Question 3

How EX2100 transmits voltage to the armature (Rotor)

Answer 3

Brushes and collector rings

Question 4

Generator Trips

Answer 4

Generator Faults (Differential and Neutral Overcurrent
Main Transformer Fault
Aux Transformer Fault
Generator overload
Generator underfrequency
        59.4 - 180 Seconds	
        57.9Hz for 110 Seconds
	57.4Hz for 15 Seconds
	56.9Hz for 2.4 Seconds

Question 5

Sequential vs Simultaneous Trip

Answer 5

Sequential trips – TSV close steam is exhausted and PCBs open on reverse power (3.75sec) and exciter stops.
Synchronous trips, all things happen together….

Question 6

Max System Voltages

Answer 6

Generator output is 24KV

230 and 500KV max is 104.9% and min is 101.3% of rated

Question 7

Generator Runback

Answer 7

Must be < 20,232 Amps in 2 mins

Must be < 6466 Amps in 3.5 mins

Question 8

Purpose of EX2100

Answer 8

PPT converts 800VAC to 125DC for field excitation

Question 9

Operation of disconnects

Answer 9

Rubber Gloves, Rubber Boots, Hard Hat, Safety Glasses, and Flame Resistant or Cotton Clothes