Relay 27 Undervoltage Test

Data records

• Relay 27 Undervoltage Test is specified for electromechanical and solid-state protective relays in acceptance testing at clause 7.9.1.B.3.5 of ANSI/NETA ATS-2025. Value: electromechanical and solid-state protective relays. Source: ANSI/NETA ATS-2025, clause 7.9.1.B.3.5. Verified 2026-10-13. Record tests.relay-27-undervoltage-test.equipment.relay.acceptance
• Relay 27 Undervoltage Test is specified for electromechanical and solid-state protective relays in maintenance testing at clause 7.9.1.B.3.5 of ANSI/NETA MTS-2023. Value: electromechanical and solid-state protective relays. Source: ANSI/NETA MTS-2023, clause 7.9.1.B.3.5. Verified 2026-10-13. Record tests.relay-27-undervoltage-test.equipment.relay.maintenance
• Relay 27 Undervoltage Test is addressed in ANSI/NETA ATS-2025. Source: ANSI/NETA ATS-2025, clause 7.9.1.B.3.5. Verified 2026-10-13. Record tests.relay-27-undervoltage-test.governed-by.ansi-neta-ats
• Relay 27 Undervoltage Test is addressed in ANSI/NETA MTS-2023. Source: ANSI/NETA MTS-2023, clause 7.9.1.B.3.5. Verified 2026-10-13. Record tests.relay-27-undervoltage-test.governed-by.ansi-neta-mts
• The undervoltage trip type test in clause 5.4.3 of IEEE 1547.1-2020 applies the Annex A.3 step function to voltage: the function is set to the end of its adjustable range closest to nominal with the trip time at its minimum, the source is held just short of the set point on its non-trip side and then stepped past it, the voltage at trip is recorded, and the sequence is repeated for each phase and for all phases together, at the opposite end of the magnitude range, at the maximum trip time and for each undervoltage trip region. Source: IEEE 1547.1-2020, clause 5.4.3. Verified 2026-10-24. Record tests.relay-27-undervoltage-test.ieee1547-1.type-test
• Clause 5.4.3.4 of IEEE 1547.1-2020 passes the undervoltage trip type test when the equipment under test stops energizing and trips inside the clearing time that IEEE 1547-2018 sets for each range, and when its evaluated adjustment ranges for magnitude and for duration cover the allowable ranges of that standard. Source: IEEE 1547.1-2020, clause 5.4.3.4. Verified 2026-10-24. Record tests.relay-27-undervoltage-test.ieee1547-1.type-test-criterion
• For distributed energy resources, clause 6.4.1 of IEEE 1547-2018 sets mandatory undervoltage tripping through two functions, UV1 and UV2, each with a default voltage, a default clearing time and a range of allowable settings that depends on the abnormal performance category (Table 11, Table 12 or Table 13, the last as amended by IEEE 1547a-2020). Under clause 4.3 the undervoltage functions respond to whichever applicable voltage is lowest in relation to nominal. Source: IEEE 1547-2018, clause 6.4.1, 4.3. Verified 2026-10-24. Record tests.relay-27-undervoltage-test.ieee1547.trip-requirements
• IEEE 2800-2022 states no undervoltage trip setting for a transmission-connected inverter-based resource plant, as clause 7.2.1 makes explicit; clause 9.3 requires any voltage protection that is applied to permit the voltage ride-through of clause 7.2.2, so the setting against which an undervoltage element is tested is a project value coordinated with the transmission system owner rather than a value from the standard. Source: IEEE 2800-2022, clause 7.2.1, 9.3. Verified 2026-10-24. Record tests.relay-27-undervoltage-test.ieee2800.no-mandatory-settings
• The test method is named Relay 27 Undervoltage Test. Value: Relay 27 Undervoltage Test. Source: Electrical Testing Reference editorial taxonomy, 2026-10 edition. Verified 2026-10-13. Record tests.relay-27-undervoltage-test.title