Data records

Name: Transformer Testing Reference data records
Creator: Transformer Testing Reference
License: https://www.transformertestingreference.com/license/

Each statement in Transformer Testing Reference is recorded as a data record with its source, verification date, review status and history. The index lists 177 records by subject.

Test methods

Bolted connection resistance

Data records for Bolted connection resistance.
Record	Statement
tests.bolted-connection-resistance.equipment.regulator.acceptance	Bolted Connection Resistance is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.1 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.bolted-connection-resistance.equipment.regulator.maintenance	Bolted Connection Resistance is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.1 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.bolted-connection-resistance.equipment.transformer-fluid.acceptance	Bolted Connection Resistance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.1 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.bolted-connection-resistance.equipment.transformer-fluid.maintenance	Bolted Connection Resistance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.1 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.bolted-connection-resistance.equipment.transformer.acceptance	Bolted Connection Resistance is specified for small low-voltage air-cooled dry-type transformers in acceptance testing at clause 7.2.1.1.B.1 of ANSI/NETA ATS-2025. Value: small low-voltage air-cooled dry-type transformers.
tests.bolted-connection-resistance.equipment.transformer.maintenance	Bolted Connection Resistance is specified for small low-voltage air-cooled dry-type transformers in maintenance testing at clause 7.2.1.1.B.1 of ANSI/NETA MTS-2023. Value: small low-voltage air-cooled dry-type transformers.

Bushing power factor and capacitance

Data records for Bushing power factor and capacitance.
Record	Statement
tests.bushing-power-factor-and-capacitance.equipment.regulator.acceptance	Bushing Power Factor and Capacitance is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.4 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.bushing-power-factor-and-capacitance.equipment.regulator.maintenance	Bushing Power Factor and Capacitance is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.4 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.bushing-power-factor-and-capacitance.equipment.transformer-fluid.acceptance	Bushing Power Factor and Capacitance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.5 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.bushing-power-factor-and-capacitance.equipment.transformer-fluid.maintenance	Bushing Power Factor and Capacitance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.5 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.

Control and functional verification

Data records for Control and functional verification.
Record	Statement
tests.control-and-functional-verification.equipment.regulator.acceptance	Control and Functional Verification is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.11 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.control-and-functional-verification.equipment.regulator.maintenance	Control and Functional Verification is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.10 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.control-and-functional-verification.equipment.transformer-fluid.acceptance	Control and Functional Verification is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.19 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.control-and-functional-verification.equipment.transformer-fluid.maintenance	Control and Functional Verification is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.19 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.control-and-functional-verification.equipment.transformer.acceptance	Control and Functional Verification is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.10 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.control-and-functional-verification.equipment.transformer.maintenance	Control and Functional Verification is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.10 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Dielectric frequency response

Data records for Dielectric frequency response.
Record	Statement
tests.dielectric-frequency-response.equipment.transformer-fluid.acceptance	Dielectric Frequency Response is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.13 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.dielectric-frequency-response.equipment.transformer-fluid.maintenance	Dielectric Frequency Response is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.13 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.

Dielectric withstand

Data records for Dielectric withstand.
Record	Statement
tests.dielectric-withstand.equipment.transformer.acceptance	Dielectric Withstand is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.9 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.dielectric-withstand.equipment.transformer.maintenance	Dielectric Withstand is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.9 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Dynamic Winding Resistance

Data records for Dynamic Winding Resistance.
Record	Statement
tests.dynamic-winding-resistance.equipment.regulator.acceptance	Dynamic Winding Resistance is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.6 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.dynamic-winding-resistance.equipment.regulator.maintenance	Dynamic Winding Resistance is specified for load tap changers in maintenance testing at clause 7.12.3.B.5 of ANSI/NETA MTS-2023. Value: load tap changers.
tests.dynamic-winding-resistance.equipment.transformer-fluid.acceptance	Dynamic Winding Resistance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.9 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.dynamic-winding-resistance.equipment.transformer-fluid.maintenance	Dynamic Winding Resistance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.9 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.dynamic-winding-resistance.governed-by.ansi-neta-ats	Dynamic Winding Resistance is addressed in ANSI/NETA ATS-2025.
tests.dynamic-winding-resistance.governed-by.ansi-neta-mts	Dynamic Winding Resistance is addressed in ANSI/NETA MTS-2023.
tests.dynamic-winding-resistance.title	The test method is named Dynamic Winding Resistance. Value: Dynamic Winding Resistance.

Gas Blanket Oxygen Content

Data records for Gas Blanket Oxygen Content.
Record	Statement
tests.gas-blanket-oxygen-content.equipment.reactor.acceptance	Gas Blanket Oxygen Content is specified for liquid-filled shunt and current-limiting reactors in acceptance testing at clause 7.20.3.2.B.6 of ANSI/NETA ATS-2025. Value: liquid-filled shunt and current-limiting reactors.
tests.gas-blanket-oxygen-content.equipment.reactor.maintenance	Gas Blanket Oxygen Content is specified for liquid-filled shunt and current-limiting reactors in maintenance testing at clause 7.20.3.2.B of ANSI/NETA MTS-2023. Value: liquid-filled shunt and current-limiting reactors.
tests.gas-blanket-oxygen-content.equipment.regulator.acceptance	Gas Blanket Oxygen Content is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.9 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.gas-blanket-oxygen-content.equipment.regulator.maintenance	Gas Blanket Oxygen Content is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.7 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.gas-blanket-oxygen-content.equipment.transformer-fluid.acceptance	Gas Blanket Oxygen Content is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.12 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.gas-blanket-oxygen-content.equipment.transformer-fluid.maintenance	Gas Blanket Oxygen Content is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.12 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.gas-blanket-oxygen-content.governed-by.ansi-neta-ats	Gas Blanket Oxygen Content is addressed in ANSI/NETA ATS-2025.
tests.gas-blanket-oxygen-content.governed-by.ansi-neta-mts	Gas Blanket Oxygen Content is addressed in ANSI/NETA MTS-2023.
tests.gas-blanket-oxygen-content.title	The test method is named Gas Blanket Oxygen Content. Value: Gas Blanket Oxygen Content.

Insulation power factor dissipation factor

Data records for Insulation power factor dissipation factor.
Record	Statement
tests.insulation-power-factor-dissipation-factor.equipment.regulator.acceptance	Insulation Power Factor Dissipation Factor is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.3 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.insulation-power-factor-dissipation-factor.equipment.regulator.maintenance	Insulation Power Factor Dissipation Factor is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.3 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.insulation-power-factor-dissipation-factor.equipment.transformer-fluid.acceptance	Insulation Power Factor Dissipation Factor is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.4 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.insulation-power-factor-dissipation-factor.equipment.transformer-fluid.maintenance	Insulation Power Factor Dissipation Factor is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.4 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.insulation-power-factor-dissipation-factor.equipment.transformer.acceptance	Insulation Power Factor Dissipation Factor is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.3 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.insulation-power-factor-dissipation-factor.equipment.transformer.maintenance	Insulation Power Factor Dissipation Factor is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.3 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Insulation resistance

Data records for Insulation resistance.
Record	Statement
tests.insulation-resistance.equipment.regulator.acceptance	Insulation Resistance is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.2 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.insulation-resistance.equipment.regulator.maintenance	Insulation Resistance is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.2 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.insulation-resistance.equipment.transformer-fluid.acceptance	Insulation Resistance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.2 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.insulation-resistance.equipment.transformer-fluid.maintenance	Insulation Resistance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.2 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.insulation-resistance.equipment.transformer.acceptance	Insulation Resistance is specified for small low-voltage air-cooled dry-type transformers in acceptance testing at clause 7.2.1.1.B.2 of ANSI/NETA ATS-2025. Value: small low-voltage air-cooled dry-type transformers.
tests.insulation-resistance.equipment.transformer.maintenance	Insulation Resistance is specified for small low-voltage air-cooled dry-type transformers in maintenance testing at clause 7.2.1.1.B.2 of ANSI/NETA MTS-2023. Value: small low-voltage air-cooled dry-type transformers.

Leakage Reactance

Data records for Leakage Reactance.
Record	Statement
tests.leakage-reactance.equipment.regulator.acceptance	Leakage Reactance is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.7 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.leakage-reactance.equipment.transformer-fluid.acceptance	Leakage Reactance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.10 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.leakage-reactance.equipment.transformer-fluid.maintenance	Leakage Reactance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.10 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.leakage-reactance.governed-by.ansi-neta-ats	Leakage Reactance is addressed in ANSI/NETA ATS-2025.
tests.leakage-reactance.governed-by.ansi-neta-mts	Leakage Reactance is addressed in ANSI/NETA MTS-2023.
tests.leakage-reactance.governed-by.ieee-c57-15	Leakage Reactance is addressed in IEEE/IEC C57.15-2017.
tests.leakage-reactance.ieeec57-12-90.factors	Clause 9.2 of IEEE C57.12.90-2021 notes that the tap position changes both the load losses and the impedance, that a rise in temperature raises the resistive loss and lowers the stray loss, and that, because the test runs at a low power factor, a phase-angle error in the metering instruments materially affects the measured loss.
tests.leakage-reactance.ieeec57-12-90.impedance-voltage-definition	IEEE C57.12.90-2021 defines impedance voltage as the voltage required to circulate rated current through one winding while the other winding is short-circuited, with the windings connected for rated voltage; it is stated relative to the energized winding's rated voltage and resolves into an in-phase resistance drop and a quadrature reactance drop that combine as a phasor sum.
tests.leakage-reactance.ieeec57-12-90.reactive-component	Clause 9.4.3 of IEEE C57.12.90-2021 separates impedance voltage into a resistance component, which is corrected to the reference temperature, and a reactance component, which is independent of temperature, and recombines them as a phasor sum.
tests.leakage-reactance.title	The test method is named Leakage Reactance. Value: Leakage Reactance.

Partial discharge online

Data records for Partial discharge online.
Record	Statement
tests.partial-discharge-online.equipment.transformer.acceptance	Partial Discharge Online is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.12 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.partial-discharge-online.equipment.transformer.maintenance	Partial Discharge Online is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.12 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Polarization index and dielectric absorption

Data records for Polarization index and dielectric absorption.
Record	Statement
tests.polarization-index-and-dielectric-absorption.equipment.regulator.maintenance	Polarization Index and Dielectric Absorption is specified for induction voltage regulators in maintenance testing at clause 7.12.1.2.B.2 of ANSI/NETA MTS-2023. Value: induction voltage regulators.

Power factor tip up

Data records for Power factor tip up.
Record	Statement
tests.power-factor-tip-up.equipment.transformer.acceptance	Power Factor Tip Up is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.4 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.power-factor-tip-up.equipment.transformer.maintenance	Power Factor Tip Up is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.4 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Resistor and coil resistance

Data records for Resistor and coil resistance.
Record	Statement
tests.resistor-and-coil-resistance.equipment.transformer-fluid.acceptance	Resistor and Coil Resistance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.18 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.resistor-and-coil-resistance.equipment.transformer-fluid.maintenance	Resistor and Coil Resistance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.18 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.

Surge arrester and spd tests

Data records for Surge arrester and spd tests.
Record	Statement
tests.surge-arrester-and-spd-tests.equipment.transformer-fluid.acceptance	Surge Arrester and SPD Tests is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.17 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.surge-arrester-and-spd-tests.equipment.transformer-fluid.maintenance	Surge Arrester and SPD Tests is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.17 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.surge-arrester-and-spd-tests.equipment.transformer.acceptance	Surge Arrester and SPD Tests is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.11 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.surge-arrester-and-spd-tests.equipment.transformer.maintenance	Surge Arrester and SPD Tests is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.11 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Sweep Frequency Response Analysis

Data records for Sweep Frequency Response Analysis.
Record	Statement
tests.sweep-frequency-response-analysis.equipment.transformer-fluid.acceptance	Sweep Frequency Response Analysis is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.7 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.sweep-frequency-response-analysis.equipment.transformer-fluid.maintenance	Sweep Frequency Response Analysis is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.7 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.sweep-frequency-response-analysis.governed-by.ansi-neta-ats	Sweep Frequency Response Analysis is addressed in ANSI/NETA ATS-2025.
tests.sweep-frequency-response-analysis.governed-by.ansi-neta-mts	Sweep Frequency Response Analysis is addressed in ANSI/NETA MTS-2023.
tests.sweep-frequency-response-analysis.title	The test method is named Sweep Frequency Response Analysis. Value: Sweep Frequency Response Analysis.

Transformer Core Insulation Resistance

Data records for Transformer Core Insulation Resistance.
Record	Statement
tests.transformer-core-insulation-resistance.equipment.transformer-fluid.acceptance	Transformer Core Insulation Resistance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.11 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.transformer-core-insulation-resistance.equipment.transformer-fluid.maintenance	Transformer Core Insulation Resistance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.11 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.transformer-core-insulation-resistance.equipment.transformer.acceptance	Transformer Core Insulation Resistance is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.8 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.transformer-core-insulation-resistance.equipment.transformer.maintenance	Transformer Core Insulation Resistance is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.8 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.
tests.transformer-core-insulation-resistance.governed-by.ansi-neta-ats	Transformer Core Insulation Resistance is addressed in ANSI/NETA ATS-2025.
tests.transformer-core-insulation-resistance.governed-by.ansi-neta-mts	Transformer Core Insulation Resistance is addressed in ANSI/NETA MTS-2023.
tests.transformer-core-insulation-resistance.title	The test method is named Transformer Core Insulation Resistance. Value: Transformer Core Insulation Resistance.

Transformer Excitation Current

Data records for Transformer Excitation Current.
Record	Statement
tests.transformer-excitation-current.equipment.regulator.acceptance	Transformer Excitation Current is specified for load tap changers in acceptance testing at clause 7.12.3.B.12 of ANSI/NETA ATS-2025. Value: load tap changers.
tests.transformer-excitation-current.equipment.regulator.maintenance	Transformer Excitation Current is specified for load tap changers in maintenance testing at clause 7.12.3.B.12 of ANSI/NETA MTS-2023. Value: load tap changers.
tests.transformer-excitation-current.equipment.transformer-fluid.acceptance	Transformer Excitation Current is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.6 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.transformer-excitation-current.equipment.transformer-fluid.maintenance	Transformer Excitation Current is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.6 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.transformer-excitation-current.equipment.transformer.acceptance	Transformer Excitation Current is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.6 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.transformer-excitation-current.equipment.transformer.maintenance	Transformer Excitation Current is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.6 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.
tests.transformer-excitation-current.governed-by.ansi-neta-ats	Transformer Excitation Current is addressed in ANSI/NETA ATS-2025.
tests.transformer-excitation-current.governed-by.ansi-neta-mts	Transformer Excitation Current is addressed in ANSI/NETA MTS-2023.
tests.transformer-excitation-current.ieeec57-12-90.basis	Clause 8.5 of IEEE C57.12.90-2021 states excitation current relative to the energized winding's rated line current, uses the smallest kVA rating as the base on a unit that carries more than one cooling-class rating, and for a three-phase unit averages the magnitudes of the line currents recorded during the no-load loss test.
tests.transformer-excitation-current.ieeec57-12-90.factory-basis	In IEEE C57.12.90-2021 excitation current is a factory quantity measured at rated voltage on a sine-wave basis during the no-load loss test of clause 8, with the test voltage set by the average-voltage voltmeter method of clause 8.2; the code gives no field procedure for excitation current.
tests.transformer-excitation-current.title	The test method is named Transformer Excitation Current. Value: Transformer Excitation Current.

Transformer Turns Ratio

Data records for Transformer Turns Ratio.
Record	Statement
tests.transformer-turns-ratio.equipment.instrument.acceptance	Transformer Turns Ratio is specified for voltage transformers in acceptance testing at clause 7.10.2.B.3 of ANSI/NETA ATS-2025. Value: voltage transformers.
tests.transformer-turns-ratio.equipment.instrument.maintenance	Transformer Turns Ratio is specified for voltage transformers in maintenance testing at clause 7.10.2.B.4 of ANSI/NETA MTS-2023. Value: voltage transformers.
tests.transformer-turns-ratio.equipment.regulator.acceptance	Transformer Turns Ratio is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.10 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.transformer-turns-ratio.equipment.regulator.maintenance	Transformer Turns Ratio is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.8 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.transformer-turns-ratio.equipment.transformer-fluid.acceptance	Transformer Turns Ratio is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.3 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.transformer-turns-ratio.equipment.transformer-fluid.maintenance	Transformer Turns Ratio is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.3 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.transformer-turns-ratio.equipment.transformer.acceptance	Transformer Turns Ratio is specified for small low-voltage air-cooled dry-type transformers in acceptance testing at clause 7.2.1.1.B.3 of ANSI/NETA ATS-2025. Value: small low-voltage air-cooled dry-type transformers.
tests.transformer-turns-ratio.equipment.transformer.maintenance	Transformer Turns Ratio is specified for small low-voltage air-cooled dry-type transformers in maintenance testing at clause 7.2.1.1.B.3 of ANSI/NETA MTS-2023. Value: small low-voltage air-cooled dry-type transformers.
tests.transformer-turns-ratio.governed-by.ansi-neta-ats	Transformer Turns Ratio is addressed in ANSI/NETA ATS-2025.
tests.transformer-turns-ratio.governed-by.ansi-neta-mts	Transformer Turns Ratio is addressed in ANSI/NETA MTS-2023.
tests.transformer-turns-ratio.governed-by.ieee-c57-12-00	Transformer Turns Ratio is addressed in IEEE C57.12.00-2021.
tests.transformer-turns-ratio.governed-by.ieee-c57-12-01	Transformer Turns Ratio is addressed in IEEE C57.12.01-2020.
tests.transformer-turns-ratio.governed-by.ieee-c57-18-10	Transformer Turns Ratio is addressed in IEEE C57.18.10-2021.
tests.transformer-turns-ratio.ieeec57-12-90.conditions	Clause 7.1 of IEEE C57.12.90-2021 runs the ratio test at rated or lower voltage and at rated or higher frequency, prefers single-phase excitation on three-phase units when each phase is accessible, and, where a wye neutral is inaccessible, creates a virtual neutral by shorting one phase with the connections of Figure 9.
tests.transformer-turns-ratio.ieeec57-12-90.definition	IEEE C57.12.90-2021 defines turns ratio as the turns of the high-voltage winding divided by the turns of the low-voltage winding, with a tapped winding taken at the turns for its normal rated voltage, and clause 7.1.1 has the ratio determined for every tap and for the full winding.
tests.transformer-turns-ratio.ieeec57-12-90.methods	Clause 7.3 of IEEE C57.12.90-2021 gives three ratio methods: two voltmeters read simultaneously and then interchanged, comparison against a transformer of known ratio, and a ratio meter based on a resistance potentiometer circuit that can also indicate polarity, phase relation and phase sequence.
tests.transformer-turns-ratio.ieeec57-12-90.tolerance-deferred	Clause 7.2 of IEEE C57.12.90-2021 contains no ratio tolerance of its own; it refers the tolerance to clause 9.1 of IEEE C57.12.00-2021.
tests.transformer-turns-ratio.title	The test method is named Transformer Turns Ratio. Value: Transformer Turns Ratio.

Vacuum interrupter integrity

Data records for Vacuum interrupter integrity.
Record	Statement
tests.vacuum-interrupter-integrity.equipment.regulator.acceptance	Vacuum Interrupter Integrity is specified for load tap changers in acceptance testing at clause 7.12.3.B.11 of ANSI/NETA ATS-2025. Value: load tap changers.
tests.vacuum-interrupter-integrity.equipment.regulator.maintenance	Vacuum Interrupter Integrity is specified for load tap changers in maintenance testing at clause 7.12.3.B.10 of ANSI/NETA MTS-2023. Value: load tap changers.

Vacuum interrupter mac test

Data records for Vacuum interrupter mac test.
Record	Statement
tests.vacuum-interrupter-mac-test.equipment.regulator.acceptance	Vacuum Interrupter MAC Test is specified for load tap changers in acceptance testing at clause 7.12.3.B.10 of ANSI/NETA ATS-2025. Value: load tap changers.
tests.vacuum-interrupter-mac-test.equipment.regulator.maintenance	Vacuum Interrupter MAC Test is specified for load tap changers in maintenance testing at clause 7.12.3.B.9 of ANSI/NETA MTS-2023. Value: load tap changers.

Visual and mechanical inspection

Data records for Visual and mechanical inspection.
Record	Statement
tests.visual-and-mechanical-inspection.equipment.regulator.acceptance	Visual and Mechanical Inspection is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.A of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.visual-and-mechanical-inspection.equipment.regulator.maintenance	Visual and Mechanical Inspection is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.A of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.visual-and-mechanical-inspection.equipment.transformer-fluid.acceptance	Visual and Mechanical Inspection is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.A of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.visual-and-mechanical-inspection.equipment.transformer-fluid.maintenance	Visual and Mechanical Inspection is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.A of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.visual-and-mechanical-inspection.equipment.transformer.acceptance	Visual and Mechanical Inspection is specified for small low-voltage air-cooled dry-type transformers in acceptance testing at clause 7.2.1.1.A of ANSI/NETA ATS-2025. Value: small low-voltage air-cooled dry-type transformers.
tests.visual-and-mechanical-inspection.equipment.transformer.maintenance	Visual and Mechanical Inspection is specified for small low-voltage air-cooled dry-type transformers in maintenance testing at clause 7.2.1.1.A of ANSI/NETA MTS-2023. Value: small low-voltage air-cooled dry-type transformers.

Winding resistance

Data records for Winding resistance.
Record	Statement
tests.winding-resistance.equipment.regulator.acceptance	Winding Resistance is specified for step voltage regulators in acceptance testing at clause 7.12.1.1.B.5 of ANSI/NETA ATS-2025. Value: step voltage regulators.
tests.winding-resistance.equipment.regulator.maintenance	Winding Resistance is specified for step voltage regulators in maintenance testing at clause 7.12.1.1.B.5 of ANSI/NETA MTS-2023. Value: step voltage regulators.
tests.winding-resistance.equipment.transformer-fluid.acceptance	Winding Resistance is specified for liquid-filled transformers in acceptance testing at clause 7.2.2.B.8 of ANSI/NETA ATS-2025. Value: liquid-filled transformers.
tests.winding-resistance.equipment.transformer-fluid.maintenance	Winding Resistance is specified for liquid-filled transformers in maintenance testing at clause 7.2.2.B.8 of ANSI/NETA MTS-2023. Value: liquid-filled transformers.
tests.winding-resistance.equipment.transformer.acceptance	Winding Resistance is specified for large air-cooled dry-type transformers in acceptance testing at clause 7.2.1.2.B.7 of ANSI/NETA ATS-2025. Value: large air-cooled dry-type transformers.
tests.winding-resistance.equipment.transformer.maintenance	Winding Resistance is specified for large air-cooled dry-type transformers in maintenance testing at clause 7.2.1.2.B.7 of ANSI/NETA MTS-2023. Value: large air-cooled dry-type transformers.

Standards

IEEE Standard for General Requirements for Dry-Type Distribution and Power Transformers

Data records for IEEE Standard for General Requirements for Dry-Type Distribution and Power Transformers.
Record	Statement
std.ieee-c57-12-01.designation	IEEE C57.12.01-2020 is the designation of the document titled IEEE Standard for General Requirements for Dry-Type Distribution and Power Transformers. Value: IEEE C57.12.01-2020.
std.ieee-c57-12-01.edition.2020	IEEE C57.12.01-2020 is the 2020 edition of the IEEE document titled IEEE Standard for General Requirements for Dry-Type Distribution and Power Transformers, published on 2020-11-24. Value: 2020.
std.ieee-c57-12-01.scope	The standard covers the electrical, mechanical and safety requirements of dry-type distribution and power transformers and autotransformers in ventilated, non-ventilated and sealed constructions, where the highest-voltage winding is above the low-voltage class stated in the datum value. Value: 601 V.
std.ieee-c57-12-01.status	The IEEE catalog lists IEEE C57.12.01-2020 with the status Active Standard. Value: Active Standard.
std.ieee-c57-12-01.title	The publisher catalog gives the full title of IEEE C57.12.01-2020 as IEEE Standard for General Requirements for Dry-Type Distribution and Power Transformers. Value: IEEE Standard for General Requirements for Dry-Type Distribution and Power Transformers.

IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers

Data records for IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers.
Record	Statement
std.ieee-c57-12-00.designation	IEEE C57.12.00-2021 is the designation of the document titled IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers. Value: IEEE C57.12.00-2021.
std.ieee-c57-12-00.edition.2021	IEEE C57.12.00-2021 is the 2021 edition of the IEEE document titled IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers, published on 2022-01-21. Value: 2021.
std.ieee-c57-12-00.scope	The standard sets general electrical and mechanical requirements for liquid-immersed distribution, power, autotransformer and regulating transformers whose highest-voltage winding is above the low-voltage class stated in the datum value, and it lists the transformer types it excludes. Value: 601 V.
std.ieee-c57-12-00.status	The IEEE catalog lists IEEE C57.12.00-2021 with the status Active Standard. Value: Active Standard.
std.ieee-c57-12-00.title	The publisher catalog gives the full title of IEEE C57.12.00-2021 as IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers. Value: IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers.

IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers

Data records for IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers.
Record	Statement
std.ieee-c57-18-10.designation	IEEE C57.18.10-2021 is the designation of the document titled IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers. Value: IEEE C57.18.10-2021.
std.ieee-c57-18-10.edition.2021	IEEE C57.18.10-2021 is the 2021 edition of the IEEE document titled IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers, published on 2022-03-29. Value: 2021.
std.ieee-c57-18-10.scope	The standard covers practices and requirements for single-phase and three-phase transformers serving dedicated semiconductor rectifier loads at or above the minimum rating stated in the datum value, including service conditions and routine tests. Value: 100 kW.
std.ieee-c57-18-10.status	The IEEE catalog lists IEEE C57.18.10-2021 with the status Active Standard. Value: Active Standard.
std.ieee-c57-18-10.title	The publisher catalog gives the full title of IEEE C57.18.10-2021 as IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers. Value: IEEE Standard Practices and Requirements for Semiconductor Power Rectifier Transformers.

IEEE Standard Test Code for Dry-Type Distribution and Power Transformers

Data records for IEEE Standard Test Code for Dry-Type Distribution and Power Transformers.
Record	Statement
std.ieee-c57-12-91.designation	IEEE C57.12.91-2020 is the designation of the document titled IEEE Standard Test Code for Dry-Type Distribution and Power Transformers. Value: IEEE C57.12.91-2020.
std.ieee-c57-12-91.edition.2020	IEEE C57.12.91-2020 is the 2020 edition of the IEEE document titled IEEE Standard Test Code for Dry-Type Distribution and Power Transformers, published on 2021-01-28. Value: 2020.
std.ieee-c57-12-91.scope	The test code describes test procedures for dry-type distribution and power transformers, and it leaves performance requirements and pass criteria to other standards or to user specifications.
std.ieee-c57-12-91.status	The IEEE catalog lists IEEE C57.12.91-2020 with the status Superseded Standard, superseded by C57.12.91-2026. Value: Superseded Standard.
std.ieee-c57-12-91.title	The publisher catalog gives the full title of IEEE C57.12.91-2020 as IEEE Standard Test Code for Dry-Type Distribution and Power Transformers. Value: IEEE Standard Test Code for Dry-Type Distribution and Power Transformers.

IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers

Data records for IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers.
Record	Statement
std.ieee-c57-12-90.approved	The IEEE SA Standards Board approved the 2021 edition of IEEE C57.12.90 on 2021-11-09. Value: 2021.
std.ieee-c57-12-90.definition.liquid	In IEEE C57.12.90-2021 the word liquid covers any insulating liquid used in a transformer, including mineral oil, natural ester, synthetic ester, silicone liquid and high molecular weight hydrocarbon.
std.ieee-c57-12-90.designation	IEEE C57.12.90-2021 is the designation of the document titled IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers. Value: IEEE C57.12.90-2021.
std.ieee-c57-12-90.dielectric-order	Clause 10.1.5.1 of IEEE C57.12.90-2021 orders the dielectric tests as lightning impulse, then switching impulse, then applied voltage, then induced voltage, with the induced-voltage test always last.
std.ieee-c57-12-90.relationship.c57-12-00	IEEE C57.12.90-2021 states test methods only; the requirements and tolerances it applies, such as the ratio tolerance referenced in clause 7.2 and the dielectric test levels referenced in clauses 10.1.2 and 10.5, are held by IEEE C57.12.00-2021.
std.ieee-c57-12-90.revision-of	IEEE C57.12.90-2021 is a revision of IEEE C57.12.90-2015. Value: 2015.
std.ieee-c57-12-90.scope	IEEE C57.12.90-2021 is a factory test code: it gives the methods for the tests that IEEE C57.12.00-2021 and related product standards specify for liquid-immersed distribution, power and regulating transformers, and clause 4.2 assumes that testing takes place at the manufacturer's works or at another facility that has been accepted for the purpose, except where a specification says otherwise. It does not apply to instrument transformers, step-voltage and induction voltage regulators, arc-furnace transformers, rectifier transformers, specialty transformers, grounding transformers or mine transformers.
std.ieee-c57-12-90.sponsor	The sponsor of IEEE C57.12.90-2021 is the Transformers Committee of the IEEE Power and Energy Society.
std.ieee-c57-12-90.structure.annex-b	Annex B of IEEE C57.12.90-2021 is normative and gives the method for converting test results between the two standard power frequencies.
std.ieee-c57-12-90.structure.calculated-data	Clause 14 of IEEE C57.12.90-2021 covers calculated data: the reference temperature used for load losses, for regulation and for efficiency, the basis on which no-load and load losses are stated, the efficiency calculation, and the voltage regulation of a constant-voltage transformer.
std.ieee-c57-12-90.structure.dielectric	Clause 10 of IEEE C57.12.90-2021 covers the dielectric tests: general conditions and the field dielectric test clause in clause 10.1, impulse tests in clauses 10.2 through 10.4, low-frequency applied and induced voltage tests in clauses 10.5 through 10.8, partial discharge measurement in clause 10.9, insulation power factor in clause 10.10 and insulation resistance in clause 10.11.
std.ieee-c57-12-90.structure.load-loss	Clause 9 of IEEE C57.12.90-2021 covers load losses and impedance voltage: definitions in clause 9.1, the factors that affect the measurement in clause 9.2, test preparation in clause 9.3, the phase-angle and temperature corrections and the impedance components in clause 9.4, and zero-sequence impedance in clause 9.5.
std.ieee-c57-12-90.structure.no-load-loss	Clause 8 of IEEE C57.12.90-2021 covers no-load losses and excitation current: the components of no-load loss and the factors that affect it, the sine-wave basis and waveform correction, the temperature correction, the basis for expressing excitation current, and conversion between power frequencies.
std.ieee-c57-12-90.structure.polarity	Clause 6 of IEEE C57.12.90-2021 covers polarity and phase relation: Figures 2 and 3 define subtractive and additive polarity, the single-phase polarity methods are in clause 6.2 and the polyphase angular displacement and phase sequence methods are in clause 6.3.
std.ieee-c57-12-90.structure.ratio	Clause 7 of IEEE C57.12.90-2021 covers the ratio test: the definition and test conditions in clause 7.1, a tolerance reference to IEEE C57.12.00-2021 in clause 7.2, and the voltmeter, comparison and ratio-meter methods in clause 7.3.
std.ieee-c57-12-90.structure.resistance	Clause 5 of IEEE C57.12.90-2021 covers winding resistance measurement: determining the cold winding temperature, converting a measured resistance to a reference temperature, the measuring methods, and the connections and reporting for wye, delta and autotransformer windings.
std.ieee-c57-12-90.structure.short-circuit	Clause 12 of IEEE C57.12.90-2021 covers the short-circuit test, grouping transformers into categories by kVA rating in Table 5 and setting in Table 6 of clause 12.5.4 the allowable change in per-phase leakage impedance after a short-circuit test series.
std.ieee-c57-12-90.structure.temperature-rise-and-sound	Clause 11 of IEEE C57.12.90-2021 covers the temperature rise test and clause 13 covers audible sound, with the sound level report forms given as Figures 36 and 37.
std.ieee-c57-12-90.test-order	A note in clause 4.3 of IEEE C57.12.90-2021 recommends that the dielectric tests come after the tests made at reduced voltage: winding resistance, polarity with phase relation, turns ratio, no-load loss with excitation current, impedance with load loss, and temperature rise.
std.ieee-c57-12-90.test-types	Clauses 4.1 and 4.2 of IEEE C57.12.90-2021 take the test categories routine, design, conformance and other from the IEEE transformer terminology standard and leave the assignment of tests to each category to Table 17 of IEEE C57.12.00-2021.
std.ieee-c57-12-90.title	The licensed copy of IEEE C57.12.90-2021 carries the full title IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers. Value: IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers.

IEEE/IEC International Standard: Power transformers, Part 21: Standard requirements, terminology, and test code for step-voltage regulators

Data records for IEEE/IEC International Standard: Power transformers, Part 21: Standard requirements, terminology, and test code for step-voltage regulators.
Record	Statement
std.ieee-c57-15.designation	IEEE/IEC C57.15-2017 is the designation of the document titled IEEE/IEC International Standard: Power transformers, Part 21: Standard requirements, terminology, and test code for step-voltage regulators. Value: IEEE/IEC C57.15-2017.
std.ieee-c57-15.edition.2017	IEEE/IEC C57.15-2017 is the 2017 edition of the IEEE/IEC international standard on requirements, terminology and test code for step-voltage regulators, published on the date stated in the datum value. Value: 2017.
std.ieee-c57-15.scope	The standard covers electrical, mechanical and test requirements for liquid-immersed single-phase and three-phase step-voltage regulators for distribution and substation use, including their controls, within stated kVA and voltage ceilings.
std.ieee-c57-15.status	The IEEE catalog lists IEEE/IEC C57.15-2017 with the status Active Standard. Value: Active Standard.
std.ieee-c57-15.title	The publisher catalog gives the full title of IEEE/IEC C57.15-2017 as IEEE/IEC International Standard: Power transformers, Part 21: Standard requirements, terminology, and test code for step-voltage regulators. Value: IEEE/IEC International Standard: Power transformers, Part 21: Standard requirements, terminology, and test code for step-voltage regulators.

Equipment classes

Liquid-filled transformers

Data records for Liquid-filled transformers.
Record	Statement
equip.liquid-filled-transformers.ats-section	Section 7.2.2 of ANSI/NETA ATS-2025 covers the acceptance testing of liquid-filled transformers.
equip.liquid-filled-transformers.ats-tables	Section 7.2.2 of ANSI/NETA ATS-2025 refers to Table 100.3 for dissipation factor or power factor, to Table 100.4 for insulating fluid limits and to Table 100.5 for transformer insulation resistance.
equip.liquid-filled-transformers.definition	A liquid-filled transformer is a transformer whose core and windings are immersed in an insulating liquid that serves both as electrical insulation and as a cooling medium.
equip.liquid-filled-transformers.ieeec57-12-90.test-code	The factory test code for liquid-filled distribution, power and regulating transformers is IEEE C57.12.90-2021, which gives the methods for the tests that IEEE C57.12.00-2021 specifies and leaves the requirements and tolerances to that general requirements standard.
equip.liquid-filled-transformers.mts-section	Section 7.2.2 of ANSI/NETA MTS-2023 covers the maintenance testing of liquid-filled transformers.