NETA Cheat Sheet 2026

The 30 highest-yield NETA facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. The effective (RMS) value of a sinusoidal AC voltage is approximately what fraction of the peak voltage? → 0.707 times the peak voltage
2. When commissioning a protection scheme that uses differential relaying on a transformer, why must the relay be configured with restraint windings? → To prevent false trips caused by transformer inrush current and CT ratio mismatch
3. When a NETA field report is transmitted electronically to a client, what best practice ensures report authenticity and prevents unauthorized alteration? → Delivering reports in PDF format with digital signature or password protection
4. A lockout/tagout procedure requires that after all energy sources are isolated, what must a technician verify before beginning work? → Verify zero energy state with an appropriately rated voltage-testing device
5. In a parallel RLC circuit at resonance, the circuit impedance is: → At its maximum value
6. In a load flow study, the bus that serves as the slack (swing) bus is responsible for: → Balancing real and reactive power mismatch in the network
7. In a series RLC circuit at resonance, which of the following is true? → Inductive and capacitive reactances are equal and cancel
8. When interpreting DGA results using the Rogers Ratio method, a ratio of CH4/H2 < 0.1 combined with C2H2/C2H4 < 0.1 is most consistent with: → Partial discharge (corona)
9. Which UPS topology provides zero transfer time to battery during a utility power outage because the load is always powered by the inverter? → Double-conversion (online) UPS
10. Which test is used to verify that a CT's accuracy class is maintained at elevated current levels, ensuring it does not saturate prematurely? → Excitation (saturation) curve test
11. The polarization index (PI) test for motor winding insulation compares the insulation resistance at: → 30 seconds and 10 minutes using the same test voltage
12. Which type of oil sample test is the best single indicator of active arcing inside a transformer? → Dissolved gas analysis (DGA) for acetylene
13. What minimum percentage of rated capacity must a battery string demonstrate during a NETA acceptance capacity test to be considered acceptable? → 80%
14. The primary purpose of a transfer trip scheme in transmission line protection is to: → Communicate a trip command to a remote breaker for high-speed clearing
15. What is the significance of the time-current characteristic curve (TCC) for an overcurrent relay? → It shows the relay's operating time as a function of fault current magnitude
16. What ANSI/IEEE standard governs the testing of metal-clad switchgear and is referenced in NETA acceptance testing specifications? → ANSI/IEEE C37.20.2
17. During a partial discharge (PD) test on high-voltage cable, the unit of measurement for discharge magnitude is: → Picocoulombs (pC)
18. When testing a directional overcurrent relay (67), which reference quantity is typically used for directional discrimination? → Polarizing voltage or current
19. Which dielectric test method is used to verify the vacuum integrity of a vacuum interrupter bottle? → DC hi-pot test across open contacts
20. What device is used to analyze harmonics in a power system? → Power quality analyzer
21. The reactance component of a transmission line impedance primarily causes: → Voltage drop proportional to reactive current and line length
22. Per NETA MTS, after completing insulation resistance testing on rotating machinery, what must be done before disconnecting the test leads? → Discharge the winding through the instrument for at least 4 times the test duration
23. Which safety precaution is mandatory before connecting a megohmmeter to a large capacitive load such as a cable run? → Verify the load is de-energized and fully discharged
24. Which document type must NETA-certified technicians produce to demonstrate compliance with ANSI/NETA testing standards? → Standardized test report forms documenting all required tests and results
25. According to NETA standards, how long should testing companies retain field test records and final reports? → A minimum of five years or as specified by contract, whichever is longer
26. According to NETA standards, calibration records for test equipment used during testing should be: → Available for review and referenced in the test report
27. A distance relay (ANSI Device 21) is most commonly applied for the protection of which of the following power system elements? → Transmission lines
28. Which law states that the algebraic sum of all currents entering and leaving a node in a circuit equals zero? → Kirchhoff's Current Law
29. During a power factor (dissipation factor) test on a power transformer bushing, an abnormally high power factor reading most likely indicates: → Moisture or contamination in the bushing insulation
30. According to NETA acceptance testing standards, individual float voltage measurements for battery strings should be recorded at which level? → Each individual cell