NERC Exam Questions and Answers Latest
Version 2025
What are the three categories of switches? - ANSWER Disconnects, Air breaks and Load
Break
What are disconnects? - ANSWER Open and close when there is no current flowing
What are sub transmission lines? - ANSWER Energized lines at voltages below 115 KV
KV for transmission Lines - ANSWER 138, 161, 230, 345 and 500
Transformer Limit (MVA) for 69 KV - ANSWER 75
Transformer Limit (MVA) for 138 KV - ANSWER 150
Transformer Limit (MVA) for 345 KV - ANSWER 700
What are the 4 types of circuit breakers? - ANSWER Oil, sf6 gas, vacuum, and air
Generators have what type of torque - ANSWER positive
2 ways to measure voltage - ANSWER Phase to phase and phase to ground
For Current flowing into protected equipment it must: - ANSWER Equal the current
flowing out or tis assumed that there is a fault
, Loss of a 1,000 MW unit results in how much HZ? - ANSWER .01
What is the Per Unit voltage at a 345 KV bus measured at 239? - ANSWER 1.012 349/345
Formula for calculating ohms with impedance - ANSWER Kv2/MVA
Motor has what type of torque - ANSWER Negative
Calculate the base impedance and the actual ohms of a 345 kv transformer where
impedance is 5% - ANSWER 1190.3 (345^2/ 100) Actual ohms: 59.5 (0.5 x 1190.3)
Normal Frequency Cycles in America - ANSWER 60 HZ
If a generator is producing 500MW and 200 MVAR, What is the generator doing? -
ANSWER Lagging
You are an external BA with a frequency bias of 20MW/0.1 HZ that sees a frequency of
60.2 Hz due to a large loss of load in the contingent Balancing Authority. If your
generator governor control system responds to this frequency deviation, approximately
how much generation change would your BA experience? - ANSWER -4MW
What is the frequency average? - ANSWER 59.64-60.36
suppose your interconenctions operates at 59.97 HZ from one minute after midnight to
noon and operates at 60.05 Hz from 12:01 to midnight. What should you do if a time
error correction was implemented just after midnight to correct for the time error
accumulated during this 24 hr period? - ANSWER Adjust the control setting to
compensate for the equipment error until repairs can be made
Version 2025
What are the three categories of switches? - ANSWER Disconnects, Air breaks and Load
Break
What are disconnects? - ANSWER Open and close when there is no current flowing
What are sub transmission lines? - ANSWER Energized lines at voltages below 115 KV
KV for transmission Lines - ANSWER 138, 161, 230, 345 and 500
Transformer Limit (MVA) for 69 KV - ANSWER 75
Transformer Limit (MVA) for 138 KV - ANSWER 150
Transformer Limit (MVA) for 345 KV - ANSWER 700
What are the 4 types of circuit breakers? - ANSWER Oil, sf6 gas, vacuum, and air
Generators have what type of torque - ANSWER positive
2 ways to measure voltage - ANSWER Phase to phase and phase to ground
For Current flowing into protected equipment it must: - ANSWER Equal the current
flowing out or tis assumed that there is a fault
, Loss of a 1,000 MW unit results in how much HZ? - ANSWER .01
What is the Per Unit voltage at a 345 KV bus measured at 239? - ANSWER 1.012 349/345
Formula for calculating ohms with impedance - ANSWER Kv2/MVA
Motor has what type of torque - ANSWER Negative
Calculate the base impedance and the actual ohms of a 345 kv transformer where
impedance is 5% - ANSWER 1190.3 (345^2/ 100) Actual ohms: 59.5 (0.5 x 1190.3)
Normal Frequency Cycles in America - ANSWER 60 HZ
If a generator is producing 500MW and 200 MVAR, What is the generator doing? -
ANSWER Lagging
You are an external BA with a frequency bias of 20MW/0.1 HZ that sees a frequency of
60.2 Hz due to a large loss of load in the contingent Balancing Authority. If your
generator governor control system responds to this frequency deviation, approximately
how much generation change would your BA experience? - ANSWER -4MW
What is the frequency average? - ANSWER 59.64-60.36
suppose your interconenctions operates at 59.97 HZ from one minute after midnight to
noon and operates at 60.05 Hz from 12:01 to midnight. What should you do if a time
error correction was implemented just after midnight to correct for the time error
accumulated during this 24 hr period? - ANSWER Adjust the control setting to
compensate for the equipment error until repairs can be made
