AEP AEP Metering & Measurement 2 — Questions and Answers
Question 1: What is the function of a potential transformer (PT) in a metering installation?
- To increase current for easier measurement
- To step down high voltage to a safe, measurable level (Correct answer)
- To measure reactive power only
- To regulate frequency
Correct answer: To step down high voltage to a safe, measurable level
Potential transformers step down high voltages to a standard low voltage (typically 120V) suitable for meter instrumentation.
Question 2: What is 'time-of-use' (TOU) metering designed to measure?
- The total energy used regardless of when it was consumed
- Energy consumption during different rate periods throughout the day (Correct answer)
- Only peak hour consumption
- Average daily consumption over a month
Correct answer: Energy consumption during different rate periods throughout the day
TOU meters record energy consumption during specific time periods (on-peak, off-peak) to enable variable rate billing.
Question 3: Which ANSI standard governs the requirements for watthour meters used by utilities like AEP?
- ANSI C12.1 (Correct answer)
- ANSI C37.1
- ANSI C84.1
- ANSI C57.12
Correct answer: ANSI C12.1
ANSI C12.1 is the American National Standard for Electric Meters, Code for Electricity Metering.
Question 4: What does 'meter multiplier' refer to in metering?
- The number of meters installed at one location
- A factor applied to meter readings when CTs or PTs are used (Correct answer)
- The accuracy rating of a meter
- The number of phases measured
Correct answer: A factor applied to meter readings when CTs or PTs are used
The meter multiplier is the ratio applied to scaled meter readings to obtain actual energy or demand values when instrument transformers are used.
Question 5: What is net metering as it applies to AEP customers with solar panels?
- A method to measure only outgoing power
- A billing arrangement where excess generation credits offset energy purchases (Correct answer)
- A way to measure total grid consumption
- A metering system for three-phase industrial customers
Correct answer: A billing arrangement where excess generation credits offset energy purchases
Net metering allows customers with renewable generation to receive credits on their bill for excess electricity fed back to the grid.
Question 6: What is the typical test voltage used when testing meter insulation resistance?
- 120V AC
- 240V DC
- 1,000V DC (Correct answer)
- 480V AC
Correct answer: 1,000V DC
Insulation resistance testing of meters typically uses 1,000V DC to verify insulation integrity between circuits and ground.
AEP AEP Metering & Measurement 2
What is the function of a potential transformer (PT) in a metering installation?