+---
+title: Electrical Acceptance Testing
+category: Electrical / Power Studies
+toc_depth: 3
+description: >
+ When to use: Field inspection, testing, and verification of new electrical
+ power distribution equipment prior to initial energization and final
+ acceptance, on commercial, institutional, industrial, and utility projects
+ from low voltage (600 V and below) through medium voltage (up to 38 kV).
+ Covers transformers, switchgear, switchboards, panelboards, motor control
+ centers, circuit breakers, protective relays, power cables, grounding,
+ instrument transformers, transfer switches, drives, and battery/UPS systems
+ per ANSI/NETA ATS, including test method selection, instrument calibration,
+ acceptance criteria, technician qualification, and the compiled test report.
+ Not intended for: power system analytical studies (use
+ sync/short-circuit-study, sync/protective-coordination-study,
+ sync/arc-flash-study); equipment procurement and factory testing for
+ switchgear (sync/low-voltage-switchgear, sync/medium-voltage-switchgear);
+ total building commissioning and functional performance testing
+ (sync/commissioning); factory acceptance testing by manufacturers;
+ structured low-voltage data/voice cabling (sync/structured-cabling); process
+ instrument loop checks and field device calibration; and ongoing maintenance
+ testing after acceptance (governed by ANSI/NETA MTS, not ATS).
+---
+
+# Scope {toc}
+
+## This standard governs the field acceptance testing of new electrical power distribution equipment and systems performed by an independent testing organization prior to initial energization and final project acceptance. {note}
+
+## Acceptance testing exists to answer one question before a system is energized: was the equipment installed correctly, and is it electrically sound? Factory and routine production tests prove the equipment left the factory in good order; they say nothing about transit damage, field assembly errors, contamination during construction, mis-torqued connections, or settings that do not match the approved studies. Acceptance testing closes that gap. It is the last independent check between a finished installation and the moment it is placed in service, and once a system is energized many of these tests become impractical or unsafe to perform. {note}
+
+## Applicable equipment and voltage range {toc}
+
+### This standard applies to electrical power distribution equipment rated 600 V and below (low voltage) through 38 kV (medium voltage) wherever acceptance testing is specified by the Owner, the authority having jurisdiction, or the Engineer of Record. {note}
+
+### Equipment within scope includes: power transformers (liquid-filled and dry-type); metal-enclosed and metal-clad switchgear; low-voltage switchgear and switchboards; panelboards and motor control centers; molded-case, insulated-case, and power circuit breakers; protective relays (electromechanical, solid-state, and microprocessor); shielded and unshielded power cables; grounding and bonding systems; current and potential (instrument) transformers; automatic transfer switches; variable frequency drives; battery, UPS, and energy storage systems; and solar photovoltaic system power equipment. {note}
+
+## Boundaries with adjacent standards {toc}
+
+### Acceptance testing verifies that installed protective settings match the approved studies; it does not perform those studies. Short-circuit, load-flow, coordination, and arc-flash analysis are governed by [[sync/short-circuit-study]], [[sync/protective-coordination-study]], and [[sync/arc-flash-study]]. {note}
+
+### This standard covers the field test program applied after switchgear is installed. Procurement, ratings, construction, and factory testing of that equipment are governed by [[sync/low-voltage-switchgear]] and [[sync/medium-voltage-switchgear]]. {note}
+
+### Electrical acceptance testing is a discrete prerequisite input to total building commissioning, not a substitute for it. Commissioning process management, functional performance testing, and systems integration testing are governed by [[sync/commissioning]]. The interface between the two is defined in the Quality Assurance section. {note}
+
+### Factory acceptance testing and routine production tests conducted by equipment manufacturers at their own facilities are governed by the applicable UL, IEEE, and IEC product standards and are outside this scope. They are factory tests, not field tests. {note}
+
+### Structured cabling (Category 5e/6/8 and fiber certification), process control loop checks and field instrument calibration, and ongoing maintenance testing performed after project acceptance are outside this scope. Maintenance testing is governed by ANSI/NETA MTS, not by the acceptance testing specifications referenced here. {note}
+
+# Referenced Standards {toc}
+
+## Equipment, materials, and field testing shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| ANSI/NETA ATS-2025 | Acceptance Testing Specifications for Electrical Power Equipment and Systems |
+| ANSI/NETA ETT-2022 | Standard for Certification of Electrical Testing Technicians |
+| NFPA 70 | National Electrical Code (Article 110, General Requirements for Electrical Installations) |
+| NFPA 70B-2023 | Recommended Practice for Electrical Equipment Maintenance |
+| NFPA 70E-2024 | Standard for Electrical Safety in the Workplace |
+| IEEE 400-2012 | Guide for Field Testing and Evaluation of the Insulation of Shielded Power Cable Systems Rated 5 kV and Above |
+| IEEE 400.2-2013 | Guide for Field Testing of Shielded Power Cable Systems Using Very Low Frequency (VLF) (less than 1 Hz) |
+| IEEE C57.12.90-2015 | Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformers |
+| IEEE C57.12.91-2011 | Standard Test Code for Dry-Type Distribution and Power Transformers |
+| IEEE C37.09-2018 | Standard Test Procedure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis |
+| IEEE 81-2012 | Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Grounding System |
+| NEMA MG 1-2021 | Motors and Generators |
+
+## Edition selection {toc}
+
+### The current edition of the governing acceptance testing specification is ANSI/NETA ATS-2025, which supersedes the 2021 edition. The 2025 edition added field test procedures for battery energy storage systems and solar photovoltaic systems and expanded the medium-voltage cable acceptance test value tables. {note}
+
+### The testing specification edition shall be selected to match the edition adopted by the project at the time of the construction contract.
+
+```datasheet
+label: Governing acceptance testing specification edition
+type: radio
+options:
+ - ANSI/NETA ATS-2025
+ - ANSI/NETA ATS-2021
+default: ANSI/NETA ATS-2025
+```
+
+# Submittals {toc}
+
+## Action submittals {toc}
+
+### The testing organization shall submit the following for review and approval before any field testing begins:
+
+- Testing organization accreditation certificate (NETA Accredited Company documentation)
+- Certifications and assigned competency level for each technician on the crew
+- Detailed test plan listing every device to be tested and the procedure for each
+- Sample test report forms for each equipment type
+- Current calibration certificates for all test instruments, traceable to NIST
+- Project-specific electrical safety plan referencing the current arc-flash study
+
+```datasheet
+label: Action submittals required before field testing
+type: checkbox
+options:
+ - Testing organization accreditation certificate
+ - Technician certifications and competency levels
+ - Detailed device-by-device test plan
+ - Sample test report forms by equipment type
+ - Instrument calibration certificates (NIST-traceable)
+ - Project-specific electrical safety plan
+default:
+ - Testing organization accreditation certificate
+ - Technician certifications and competency levels
+ - Detailed device-by-device test plan
+ - Sample test report forms by equipment type
+ - Instrument calibration certificates (NIST-traceable)
+ - Project-specific electrical safety plan
+```
+
+### The testing organization shall receive the approved short-circuit, coordination, and arc-flash studies as reference documents before testing begins, so that installed relay settings and trip device settings can be verified against the engineered values.
+
+## Informational submittals {toc}
+
+### The testing organization shall submit the following reference and qualification documents for the record:
+
+- Resume or equivalent qualification record for the designated crew lead
+- List of test instruments by manufacturer, model, serial number, and calibration date
+- Manufacturer published tolerance data for equipment being tested, where acceptance criteria reference manufacturer values
+
+```datasheet
+label: Informational submittals
+type: checkbox
+options:
+ - Crew lead qualification record
+ - Test instrument inventory with calibration dates
+ - Manufacturer published tolerance data
+default:
+ - Crew lead qualification record
+ - Test instrument inventory with calibration dates
+ - Manufacturer published tolerance data
+```
+
+## Closeout submittals {toc}
+
+### Upon completion of testing, the testing organization shall submit the following as project closeout deliverables:
+
+- Final compiled test report covering every device tested, with as-found and as-left values
+- Summary of all out-of-tolerance findings and the corrective action taken for each
+- Index of devices tested cross-referenced to the approved test plan
+- Copies of all instrument calibration certificates valid for the test period
+
+```datasheet
+label: Closeout submittals
+type: checkbox
+options:
+ - Final compiled test report (all devices)
+ - Out-of-tolerance findings and corrective actions
+ - Device index cross-referenced to test plan
+ - Instrument calibration certificates for test period
+default:
+ - Final compiled test report (all devices)
+ - Out-of-tolerance findings and corrective actions
+ - Device index cross-referenced to test plan
+ - Instrument calibration certificates for test period
+```
+
+### The final test report shall be delivered to the Owner, the Engineer of Record, and the authority having jurisdiction in the format and quantity specified below.
+
+```datasheet
+label: Final test report delivery format
+type: checkbox
+options:
+ - Electronic PDF (searchable)
+ - Stamped and signed hard copies
+ - Native test-set data files (COMTRADE, instrument exports)
+default:
+ - Electronic PDF (searchable)
+ - Stamped and signed hard copies
+```
+
+```datasheet
+label: Test report recipients
+type: checkbox
+options:
+ - Owner / facility records
+ - Engineer of Record
+ - Authority having jurisdiction
+ - Commissioning agent
+default:
+ - Owner / facility records
+ - Engineer of Record
+ - Authority having jurisdiction
+```
+
+```datasheet
+label: Test report retention period
+type: radio
+options:
+ - Life of the equipment
+ - 10 years
+ - 5 years
+default: Life of the equipment
+```
+
+# Quality Assurance {toc}
+
+## Independence of the testing organization {toc}
+
+### NETA requires that field acceptance testing be performed by an organization with no financial interest in the outcome of the work it tests. An installing contractor who tests its own installation has every incentive to pass marginal results and no independent check on whether the work was done correctly. Independence is the entire value of the program; without it the test report is self-certification. {note}
+
+### Acceptance testing shall be performed by an independent testing organization that is not the installing electrical contractor and has no financial interest in the installation under test.
+
+### The testing organization shall be a NETA Accredited Company (NAC), or an owner-furnished in-house testing group meeting the same accreditation, instrument calibration, and technician certification requirements.
+
+### A specification that requires only a "NETA-compliant" testing firm allows non-accredited contractors to claim compliance. Accreditation shall be stated explicitly as a NETA Accredited Company, not as general compliance. {note}
+
+```datasheet
+label: Testing organization qualification
+type: radio
+options:
+ - NETA Accredited Company (NAC), independent third party
+ - Owner-furnished in-house group meeting NAC standards
+ - OEM field service paired with independent NETA testing
+default: NETA Accredited Company (NAC), independent third party
+```
+
+## Technician qualification {toc}
+
+### Technician competency is defined by ANSI/NETA ETT, which establishes four certification levels. Level 3 is the practical minimum for a crew lead on a distribution project: a Level 3 technician can independently perform and evaluate the full range of acceptance tests and direct lower-level technicians. Specifying a higher level than the work warrants raises cost without improving outcomes; specifying too low a level puts inexperienced technicians in charge of go/no-go decisions. {note}
+
+### Each test crew shall be led by a technician certified to the specified ANSI/NETA ETT level minimum.
+
+```datasheet
+label: Crew lead minimum ETT certification level
+type: radio
+options:
+ - ETT Level 2
+ - ETT Level 3
+ - ETT Level 4
+default: ETT Level 3
+```
+
+### Personnel performing energized work shall be qualified under NFPA 70E-2024 and shall use the arc-flash personal protective equipment determined by the project arc-flash study.
+
+## Test instrument calibration {toc}
+
+### A test instrument that is out of calibration produces numbers that look authoritative and may be wrong. Acceptance decisions rest on absolute measurements compared against tight tolerances, so the instruments must be traceable to a national standard and recently verified. {note}
+
+### All test instruments shall have current calibration traceable to NIST, performed within the 12 months preceding the test.
+
+### Calibration stickers showing the instrument serial number and calibration date shall be documented in the test report for each instrument used.
+
+## Coordination with commissioning {toc}
+
+### Acceptance testing verifies equipment integrity (insulation, timing, contact resistance, settings) before energization. Commissioning functional testing verifies that energized systems perform their intended function. The two are sequential and complementary; treating them as one scope causes scheduling disputes with the commissioning agent. The boundary shall be documented so neither program assumes the other will perform a given test. {note}
+
+### Acceptance testing shall be completed and the results accepted before the affected equipment is released to the commissioning agent for functional performance testing under [[sync/commissioning]].
+
+## Hold points and scheduling {toc}
+
+### Without a contractual hold point requiring acceptance test sign-off before energization, systems are routinely energized before testing is complete, after which many de-energized tests become impractical or unsafe. The hold point is what makes the program enforceable. {note}
+
+### A formal hold point shall be established at which acceptance test results for each system are reviewed and signed off by the Engineer of Record before that system is energized.
+
+### Equipment installed in concealed spaces shall be acceptance-tested before architectural closure (ceilings, walls, flooring) renders it inaccessible.
+
+### The final compiled test report shall be reviewed and accepted by the Engineer of Record before the certificate of substantial completion is issued.
+
+```datasheet
+label: Testing milestone relative to project schedule
+type: radio
+options:
+ - Before energization, per-system hold point
+ - Before substantial completion
+ - Before final payment
+default: Before energization, per-system hold point
+```
+
+```datasheet
+label: Testing sequencing
+type: radio
+options:
+ - Single mobilization, all equipment at once
+ - Phased / sequential energization of feeders with defined hold points
+default: Phased / sequential energization of feeders with defined hold points
+```
+
+# Scope of Equipment Tested {toc}
+
+## A specification that omits an explicit equipment inclusion list invites scope disputes: the testing organization tests the obvious major equipment, and panelboards, transfer switches, or drives are quietly energized without testing. The equipment list is the single most important thing the specifier controls, because everything not listed tends not to get tested. {note}
+
+## The default acceptance test scope is 100% of installed distribution equipment. Selective sampling shall be used only where the Engineer of Record has specifically authorized it and shall be defined by an explicit inclusion and exclusion list by equipment type and voltage class. {note}
+
+## Equipment to be acceptance-tested shall be selected from the list below; any equipment present on the project and not selected shall be explicitly identified as excluded with the reason recorded.
+
+```datasheet
+label: Equipment included in acceptance test scope
+type: checkbox
+options:
+ - Power transformers (liquid-filled)
+ - Power transformers (dry-type)
+ - Metal-clad / metal-enclosed switchgear
+ - Low-voltage switchgear and switchboards
+ - Panelboards
+ - Motor control centers
+ - Molded-case and insulated-case circuit breakers
+ - Power (drawout) circuit breakers
+ - Protective relays
+ - Medium-voltage power cables
+ - Low-voltage power cables
+ - Grounding and bonding system
+ - Instrument transformers (CT / PT)
+ - Automatic transfer switches
+ - Variable frequency drives
+ - Battery / UPS systems
+default:
+ - Power transformers (liquid-filled)
+ - Power transformers (dry-type)
+ - Metal-clad / metal-enclosed switchgear
+ - Low-voltage switchgear and switchboards
+ - Panelboards
+ - Motor control centers
+ - Molded-case and insulated-case circuit breakers
+ - Power (drawout) circuit breakers
+ - Protective relays
+ - Medium-voltage power cables
+ - Low-voltage power cables
+ - Grounding and bonding system
+ - Instrument transformers (CT / PT)
+ - Automatic transfer switches
+```
+
+```datasheet
+label: Acceptance test coverage
+type: radio
+options:
+ - 100% of installed distribution equipment
+ - Selective sampling per authorized inclusion/exclusion list
+default: 100% of installed distribution equipment
+```
+
+# Acceptance Criteria {toc}
+
+## Where both a manufacturer published tolerance and a NETA table value exist for the same test, the specification must state which governs and which takes precedence on conflict; otherwise the testing organization decides case by case and results are inconsistent across the project. {note}
+
+## The source of acceptance criteria shall be stated below. Where the selected source is silent on a given test, the other source shall apply.
+
+```datasheet
+label: Primary source of acceptance criteria
+type: radio
+options:
+ - Manufacturer published tolerances govern; NETA tables where manufacturer is silent
+ - NETA ATS tolerance tables govern; manufacturer values where NETA is silent
+default: NETA ATS tolerance tables govern; manufacturer values where NETA is silent
+```
+
+## Contact and milliohm resistance acceptance {toc}
+
+### Contact resistance is a sensitive indicator of connection quality: a loose bolt, a contaminated contact surface, or partial conductor seating all show up as elevated resistance long before they cause a visible failure. Measurement is taken with a high-current micro-ohmmeter, and the result is judged against either the manufacturer baseline or the NETA table value. {note}
+
+### Bolted and contact connection resistance shall be measured and shall be rejectable when it exceeds 125% of the manufacturer published value, or the applicable NETA ATS table value where no manufacturer value is provided.
+
+```datasheet
+label: Contact / milliohm resistance acceptance threshold
+type: radio
+options:
+ - "> 125% of manufacturer published value (or NETA table)"
+ - "> 150% of manufacturer published value"
+default: "> 125% of manufacturer published value (or NETA table)"
+```
+
+```datasheet
+label: Contact resistance test current
+type: range
+unit: A DC
+min: 10
+max: 200
+step: 10
+default: 100
+```
+
+# Insulation Resistance Testing {toc}
+
+## Insulation resistance testing applies a DC voltage across insulation and measures the resulting leakage current, expressed as resistance. It is the most widely applied acceptance test because it catches contamination, moisture, and physical damage to insulation across almost every class of equipment. The test voltage must be matched to the equipment rating: too low a voltage misses defects, too high a voltage can stress sound insulation unnecessarily. {note}
+
+## Test voltage selection {toc}
+
+### The DC test voltage shall be selected from NETA ATS Table 100.1 according to the rated voltage of the equipment under test. {note}
+
+### Insulation resistance test voltage shall be selected per the following equipment voltage classes.
+
+```datasheet
+label: Insulation resistance test voltage by equipment class
+type: radio
+options:
+ - 500 V DC (120-240 V equipment)
+ - 1000 V DC (600 V equipment)
+ - 2500 V DC (2.5 kV equipment, up to 5 kV)
+ - 5000 V DC (5-15 kV equipment)
+default: 1000 V DC (600 V equipment)
+```
+
+## Acceptance values {toc}
+
+### Insulation resistance on 600 V equipment shall be measured at 1000 V DC for a 1-minute reading, with a minimum acceptable value of 1 MΩ per kV of rated voltage.
+
+### New 600 V equipment in sound condition typically reads between 100 MΩ and 1000 MΩ; any reading below 1 MΩ is rejectable and shall be investigated before energization. {note}
+
+```datasheet
+label: Insulation resistance minimum acceptance (600 V class)
+type: range
+unit: MΩ
+min: 1
+max: 100
+step: 1
+default: 100
+```
+
+### For rotating machines, transformers, and other windings where a polarization index is taken, the ratio of the 10-minute reading to the 1-minute reading shall be evaluated against the minimum below.
+
+```datasheet
+label: Polarization index (PI) minimum acceptance ratio
+type: range
+unit: ratio
+min: 1.0
+max: 3.0
+step: 0.25
+default: 2.0
+```
+
+# Medium-Voltage Cable Testing {toc}
+
+## Medium-voltage cable acceptance testing is where method selection matters most. DC high-potential (hipot) testing was the legacy field method, but DC voltage is now known to damage extruded dielectric (XLPE and EPR) insulation by injecting space charge that accelerates water-tree growth. Industry practice has moved to very low frequency (VLF) testing at 0.1 Hz, which stresses the insulation realistically without the DC damage mechanism. VLF can be run as a simple withstand test (pass/fail at voltage) or with tan-delta (dissipation factor) monitoring, which also grades the overall condition of the cable. {note}
+
+## DC hipot shall not be specified for new extruded-dielectric (XLPE or EPR) medium-voltage cable.
+
+## VLF withstand or VLF tan-delta per IEEE 400.2 shall be used for new extruded-dielectric cable work; DC hipot is retained only for testing legacy systems where it is already established.
+
+## Cable test method {toc}
+
+### The medium-voltage cable acceptance test method shall be selected below.
+
+```datasheet
+label: Medium-voltage cable test method
+type: radio
+options:
+ - VLF withstand at 0.1 Hz
+ - VLF tan-delta (dissipation factor) at 0.1 Hz
+ - DC hipot (legacy systems only)
+default: VLF withstand at 0.1 Hz
+```
+
+## VLF withstand criteria {toc}
+
+### VLF withstand testing applies 0.1 Hz AC at twice the phase-to-ground voltage (2U0) for a sustained period; the cable passes if no dielectric breakdown occurs over the full duration. For 15 kV class cable, U0 is approximately 8.66 kV, so the test voltage is approximately 17.3 kV. {note}
+
+### Each medium-voltage cable shall be VLF withstand tested at 0.1 Hz at the specified multiple of U0 for the specified duration with no dielectric breakdown.
+
+```datasheet
+label: VLF withstand test voltage
+type: radio
+options:
+ - 2U0 (twice phase-to-ground voltage)
+ - 1.5U0
+ - 3U0
+default: 2U0 (twice phase-to-ground voltage)
+```
+
+```datasheet
+label: VLF withstand test duration
+type: range
+unit: min
+min: 15
+max: 60
+step: 5
+default: 60
+```
+
+## VLF tan-delta criteria {toc}
+
+### Tan-delta measures dielectric loss, which rises as insulation degrades. Two numbers matter: the absolute loss at operating voltage, and how much the loss changes as voltage is raised (tip-up). Both are evaluated against the limits below per IEEE 400.2. {note}
+
+### Where tan-delta is specified, the dissipation factor measured at 1U0 shall not exceed the limit below for XLPE and EPR insulation.
+
+```datasheet
+label: Tan-delta (dissipation factor) limit at 1U0, XLPE/EPR
+type: range
+unit: "%"
+min: 0.05
+max: 0.20
+step: 0.01
+default: 0.10
+```
+
+### The change in tan-delta (tip-up) between 0.5U0 and 2U0 for XLPE cable shall not exceed the limit below.
+
+```datasheet
+label: Tan-delta tip-up limit (0.5U0 to 2U0), XLPE
+type: range
+unit: "%"
+min: 0.02
+max: 0.10
+step: 0.01
+default: 0.06
+```
+
+## Cable insulation resistance {toc}
+
+### Medium-voltage cable insulation resistance shall be measured at 2500 V to 5000 V DC per NETA ATS Table 100.1 before the VLF test is applied, to confirm the cable is fit to receive the higher test voltage.
+
+# Transformer Testing {toc}
+
+## Transformer acceptance testing confirms three things: that the windings are electrically continuous and correctly connected (turns ratio, winding resistance), that the insulation is dry and clean (insulation resistance, power factor), and that the unit was not damaged in shipment or installation. The test methods follow IEEE C57.12.90 for liquid-filled units and C57.12.91 for dry-type units. {note}
+
+## Turns ratio {toc}
+
+### Transformer turns ratio (TTR) shall be measured at every tap position and shall be within 0.5% of the nameplate ratio per NETA ATS Section 7.2.
+
+```datasheet
+label: Turns ratio (TTR) acceptance tolerance
+type: range
+unit: "%"
+min: 0.25
+max: 1.0
+step: 0.25
+default: 0.5
+```
+
+```datasheet
+label: Turns ratio test scope
+type: radio
+options:
+ - All tap positions
+ - Nominal tap only
+default: All tap positions
+```
+
+## Insulation power factor {toc}
+
+### Insulation power factor (also called dissipation factor) grades the overall condition of the insulation system and oil. It is the most sensitive transformer insulation test and is measured with a high-voltage power factor (dissipation factor) test set. {note}
+
+### Insulation power factor testing shall be performed on all liquid-filled transformers; dry-type transformers shall be power-factor tested where specified below.
+
+### The corrected insulation power factor of liquid-filled transformers at 20°C shall not exceed the value below per NETA ATS Table 100.5; values above 1.0% at 20°C warrant investigation.
+
+```datasheet
+label: Liquid-filled transformer insulation power factor limit at 20°C
+type: range
+unit: "%"
+min: 0.5
+max: 1.0
+step: 0.1
+default: 0.5
+```
+
+```datasheet
+label: Dry-type transformer power factor testing
+type: radio
+options:
+ - Required
+ - Not required (insulation resistance only)
+default: Not required (insulation resistance only)
+```
+
+## Winding insulation resistance {toc}
+
+### Transformer winding insulation resistance shall be measured at the DC test voltage corresponding to the winding rated voltage, with a polarization index taken where specified.
+
+# Circuit Breaker Testing {toc}
+
+## Circuit breaker acceptance testing verifies that the breaker will both carry normal current with low losses and operate fast enough to clear a fault. Contact resistance addresses the first; timing and travel analysis address the second. For drawout and power circuit breakers, timing is measured with a travel analyzer that records when each pole opens and closes, per IEEE C37.09. {note}
+
+## Contact resistance {toc}
+
+### The main-contact resistance of each circuit breaker pole shall be measured in microohms and shall be within the manufacturer tolerance, or the NETA ATS Table 100.12 value where no manufacturer value is provided.
+
+### Typical acceptable main-contact resistance ranges from 15 µΩ to 100 µΩ on a 1200 A frame and 5 µΩ to 50 µΩ on a 2000 A and larger frame; readings well above these ranges indicate a contact or connection problem. {note}
+
+## Timing and travel {toc}
+
+### For medium-voltage power circuit breakers, opening and closing times shall be measured with a travel analyzer and shall be within the manufacturer published tolerance.
+
+### Pole-to-pole timing spread (the difference between the first and last pole to operate) shall not exceed the value below.
+
+```datasheet
+label: Circuit breaker 3-pole timing spread limit
+type: range
+unit: ms
+min: 1
+max: 5
+step: 0.5
+default: 2
+```
+
+```datasheet
+label: Circuit breaker timing tolerance vs. manufacturer
+type: range
+unit: "%"
+min: 5
+max: 15
+step: 5
+default: 10
+```
+
+## Molded-case breaker trip testing {toc}
+
+### Molded-case and insulated-case breakers shall be primary-current injection tested to verify long-time and instantaneous trip operation against the published trip curve, on a sampling basis where specified.
+
+```datasheet
+label: Molded-case breaker trip test scope
+type: radio
+options:
+ - All breakers above a specified frame size
+ - Sample of each frame size and type
+ - All breakers
+default: All breakers above a specified frame size
+```
+
+# Protective Relay Testing {toc}
+
+## Protective relays are tested by injecting known currents and voltages with a relay test set and verifying that the relay picks up and times out exactly as its settings dictate. The critical discipline is that the field settings must match the approved coordination study; a relay that tests perfectly against the wrong settings is a coordination failure waiting to happen. The testing organization must therefore work from the stamped coordination study, not from settings transcribed in the field. {note}
+
+## Relay test scope {toc}
+
+### The protective relay test scope shall be selected below. A functional trip test confirms the relay trips its breaker; characteristic verification confirms the timing curve; injection testing with a calibrated relay test set is required to confirm settings match the study. {note}
+
+```datasheet
+label: Protective relay test scope
+type: radio
+options:
+ - Functional trip test only
+ - Functional trip plus pickup/timing verification at set points
+ - Full characteristic verification with relay test-set injection
+default: Full characteristic verification with relay test-set injection
+```
+
+## Settings verification {toc}
+
+### Installed relay settings shall be verified against the approved coordination study from [[sync/protective-coordination-study]]; any discrepancy shall be reported to the Engineer of Record before the relay is placed in service.
+
+### Overcurrent relay operating time shall be verified by injecting test current at 2× and 5× pickup, and the measured operate time shall be within 5% of the published time-current curve at each multiple.
+
+```datasheet
+label: Overcurrent relay timing tolerance
+type: range
+unit: "%"
+min: 3
+max: 10
+step: 1
+default: 5
+```
+
+### Overcurrent relay pickup current shall be within 5% of the set value.
+
+```datasheet
+label: Relay pickup tolerance
+type: range
+unit: "%"
+min: 3
+max: 10
+step: 1
+default: 5
+```
+
+# Grounding System Testing {toc}
+
+## Grounding acceptance testing measures the resistance of the grounding electrode system to remote earth, which determines how effectively fault current and surge energy are conducted to ground. The fall-of-potential method per IEEE 81 is the reference field method. The acceptance value depends on the facility: sensitive electronic and substation grounds require a low resistance, while general installations are held to a looser limit consistent with NEC 250.53. {note}
+
+## The grounding electrode system resistance to ground shall be measured by the fall-of-potential method per IEEE 81 and shall not exceed the limit selected below.
+
+```datasheet
+label: Ground resistance acceptance limit
+type: radio
+options:
+ - 5 Ω (substations, sensitive electronic facilities)
+ - 25 Ω (general installations, NEC 250.53)
+ - 1 Ω (large substations, special requirements)
+default: 5 Ω (substations, sensitive electronic facilities)
+```
+
+## Continuity of equipment grounding and bonding connections shall be verified per [[sync/grounding-and-bonding]] for all equipment within the test scope.
+
+# Instrument Transformer and Auxiliary Equipment Testing {toc}
+
+## Current and potential transformers feed the relays and metering; if their ratio or polarity is wrong, every downstream measurement and protection function is wrong. Ratio, polarity, and insulation are verified at acceptance. Automatic transfer switches and drives have their own functional acceptance checks that confirm transfer timing and protective settings before the systems they serve are commissioned. {note}
+
+## Current and potential transformer ratio and polarity shall be verified, and insulation resistance measured, before the associated metering and protection are placed in service.
+
+## Automatic transfer switch acceptance testing shall verify transfer and re-transfer operation, timing, and any associated protective settings; coordination of the standby source is governed by [[sync/emergency-and-standby-power]].
+
+## Variable frequency drive acceptance testing shall verify control power, insulation resistance of power circuits, and protective trip functions per the manufacturer field commissioning procedure; drive application requirements are governed by [[sync/low-voltage-variable-frequency-drives]].
+
+# Test Reporting {toc}
+
+## The test report is the permanent record of the as-installed condition of the electrical system and the baseline against which all future maintenance testing is judged per NFPA 70B. Informal field notes do not satisfy AHJ record-keeping requirements and cannot serve as a maintenance baseline. The report must capture, for every device, what was found, what tolerance applied, and whether it passed, with the instruments and their calibration identified. {note}
+
+## The test report shall include, for each device tested: device identification, the test performed, the as-found and as-left values, the applicable acceptance tolerance, the pass/fail determination, and the instruments used with their calibration dates.
+
+## All out-of-tolerance findings shall be recorded together with the corrective action taken and the as-left retest result.
+
+## The compiled report shall be indexed against the approved test plan so that any device omitted from testing is immediately apparent.
+
+```datasheet
+label: Out-of-tolerance disposition
+type: radio
+options:
+ - Repair and retest until within tolerance
+ - Repair, retest, and engineer review before energization
+ - Reject and replace
+default: Repair, retest, and engineer review before energization
+```
+
+# Field Quality Control {toc}
+
+## Visual and mechanical inspection precedes every electrical test: a technician confirms the equipment is correctly installed, anchored, labeled, and free of shipping braces and debris before any voltage is applied. Many defects are caught here, before an instrument is connected. {note}
+
+## A visual and mechanical inspection shall be performed on each device before electrical testing, confirming correct installation, anchorage, labeling per [[sync/equipment-labeling]], removal of shipping restraints, and torque verification of accessible bolted connections.
+
+## Bolted electrical connections shall be torque-verified to the manufacturer published values, or calibrated to a low-resistance measurement where torque access is not practical.
+
+## The testing organization shall coordinate any required partial or phased energization with the serving utility and shall observe the project hold points before each energization step.
+
+# Delivery, Storage, and Handling {toc}
+
+## Test instruments and reference equipment shall be transported and stored so that their calibration is not disturbed, and any instrument subjected to physical shock shall be re-verified before use.
+
+## Equipment awaiting acceptance testing shall be protected from construction moisture and contamination; space heaters in switchgear and transformers shall be energized where provided, since damp insulation will fail insulation resistance and power factor tests that the equipment would otherwise pass. {note}
+
+# Warranty {toc}
+
+## The testing organization shall warrant that all testing was performed in accordance with the specified acceptance testing specification and that the reported results accurately represent the as-found and as-left condition of the equipment.
+
+## Acceptance testing does not extend or alter the equipment manufacturer warranties; defects revealed by testing shall be corrected under the applicable equipment or installation warranty. {note}