1
RC NERC EXAM|
UPDATE|COMPREHENSIVE FREQUENT
MOST-TESTED QUESTIONS AND
VERIFIED ANSWERS/SOLUTIONS|GET IT
100% ACCURATE!!
What is ACE? - (ANSWER)(NIa - NIs) - 10β(fa - fs) - Ime
Calculated every 6 seconds
Uses Tie line Frequency Bias
What is Tie line deviation? - (ANSWER)Largest offset to ACE
What is NIA? - (ANSWER)Net Interchange Actual (sum of all tie-line values)
What is NIS? - (ANSWER)Net Interchange Scheduled (sum of all interchange
schedules)
What is the multiplier for frequency bias? - (ANSWER)10
What is β? - (ANSWER)Frequency bias - represented as negative number in ACE
calculation - reflects area natural response to frequency changes (Inertia,
Governor, Load) - atleast 1% of annual peak load for areas with native load - 1% of
peak generation output for area with no load
,2
What is FA? - (ANSWER)Frequency Actual
What is FS? - (ANSWER)Frequency Schedule - normally 60.00 HZ except for time
corrections - +/- .02 Hz
What is IME? - (ANSWER)Meter error
fudge factor
used for inadvertent bilateral payback
Negligible
What should be done if unable to calculate ACE for 30 minutes? -
(ANSWER)Contact RC
How often should time error and frequency devices be checked/calibrated? -
(ANSWER)Annually
Negative Ace - (ANSWER)The BA is Undergenerating
Positve ACE - (ANSWER)The BA is Overgenerating
What happens during Internal Loss of Load? - (ANSWER)Frequency and ACE
increase.
, 3
What happens during External Loss of Load? - (ANSWER)Frequency increases, no
change in ACE.
What is the Frequency Bias Setting? - (ANSWER)Monthly average >= 1% of
estimated yearly peak demand per 0.1 Hz
When should the Balancing Authority recalculate its Frequency Bias Setting? -
(ANSWER)By January 1 of each year
What happens when there is internal generation loss? - (ANSWER)Frequency and
ACE drop, tie-line flows increase into the system
What happens when there is external generation loss? - (ANSWER)Frequency
drops, no change in ACE, net tie-line flows increase out of the system
What happens when Frequency bias setting is lower than frequency response? -
(ANSWER)ACE will be positive causing the AGC to lower generation
What is the percentage change in load required for a 1% change in frequency? -
(ANSWER)1% - 2% change in load
What is the load reduction when Transmission Customer Voltage is reduced by
5%? - (ANSWER)Load will reduce by 3%
RC NERC EXAM|
UPDATE|COMPREHENSIVE FREQUENT
MOST-TESTED QUESTIONS AND
VERIFIED ANSWERS/SOLUTIONS|GET IT
100% ACCURATE!!
What is ACE? - (ANSWER)(NIa - NIs) - 10β(fa - fs) - Ime
Calculated every 6 seconds
Uses Tie line Frequency Bias
What is Tie line deviation? - (ANSWER)Largest offset to ACE
What is NIA? - (ANSWER)Net Interchange Actual (sum of all tie-line values)
What is NIS? - (ANSWER)Net Interchange Scheduled (sum of all interchange
schedules)
What is the multiplier for frequency bias? - (ANSWER)10
What is β? - (ANSWER)Frequency bias - represented as negative number in ACE
calculation - reflects area natural response to frequency changes (Inertia,
Governor, Load) - atleast 1% of annual peak load for areas with native load - 1% of
peak generation output for area with no load
,2
What is FA? - (ANSWER)Frequency Actual
What is FS? - (ANSWER)Frequency Schedule - normally 60.00 HZ except for time
corrections - +/- .02 Hz
What is IME? - (ANSWER)Meter error
fudge factor
used for inadvertent bilateral payback
Negligible
What should be done if unable to calculate ACE for 30 minutes? -
(ANSWER)Contact RC
How often should time error and frequency devices be checked/calibrated? -
(ANSWER)Annually
Negative Ace - (ANSWER)The BA is Undergenerating
Positve ACE - (ANSWER)The BA is Overgenerating
What happens during Internal Loss of Load? - (ANSWER)Frequency and ACE
increase.
, 3
What happens during External Loss of Load? - (ANSWER)Frequency increases, no
change in ACE.
What is the Frequency Bias Setting? - (ANSWER)Monthly average >= 1% of
estimated yearly peak demand per 0.1 Hz
When should the Balancing Authority recalculate its Frequency Bias Setting? -
(ANSWER)By January 1 of each year
What happens when there is internal generation loss? - (ANSWER)Frequency and
ACE drop, tie-line flows increase into the system
What happens when there is external generation loss? - (ANSWER)Frequency
drops, no change in ACE, net tie-line flows increase out of the system
What happens when Frequency bias setting is lower than frequency response? -
(ANSWER)ACE will be positive causing the AGC to lower generation
What is the percentage change in load required for a 1% change in frequency? -
(ANSWER)1% - 2% change in load
What is the load reduction when Transmission Customer Voltage is reduced by
5%? - (ANSWER)Load will reduce by 3%
