Circuit Breaker Reference

Data record tests.vacuum-interrupter-integrity.equipment.breaker-vacuum.maintenance

Verified 2026-10-29 Confidence: High

Vacuum Interrupter Integrity is specified for medium-voltage vacuum circuit breakers in maintenance testing at clause 7.6.3.B.7 of ANSI/NETA MTS-2023. The clause calls for a dielectric withstand voltage test across each open vacuum bottle, in strict accordance with the manufacturer's published data, as the integrity check of the interrupter.

Value: medium-voltage vacuum circuit breakers

ProvenanceANSI/NETA MTS-2023 supports data record tests.vacuum-interrupter-integrity.equipment.breaker-vacuum.maintenance, which is cited on the entry Vacuum Interrupter Integrity.SOURCEANSI/NETA MTS-2023ANSI/NETA MTS-2023Licensed standard, clause 7.6.3.B.7DATA RECORDtests.vacuum-interrupter-integrity.equipment.breaker-vacuum.maintenancetests.vacuum-interrupter..Verified 2026-10-29ENTRYVacuum Interrupter IntegrityVacuum Interrupter Integ..No revisions
Provenance. Where this record comes from and where it is used: the cited source, the record itself and the entry that cites it.
Provenance: the chain from source to entry.
StepItemDetail
SourceANSI/NETA MTS-2023Licensed standard, clause 7.6.3.B.7
Data recordtests.vacuum-interrupter-integrity.equipment.breaker-vacuum.maintenanceVerified 2026-10-29
EntryVacuum Interrupter IntegrityNo revisions
Subject
Vacuum Interrupter Integrity (Test methods)
Kind
Equipment fact
Source
ANSI/NETA MTS-2023, clause 7.6.3.B.7, Maintenance Testing Specifications for Electrical Power Equipment and Systems, NETA. Publisher page for ANSI/NETA MTS-2023Publisher information page
Also stated in
  • FIST 3-16, section 6.1.2, page 42 (May 2024).
    Read the reference passage

    6.1.2 Design and Operation

    "Vacuum circuit breakers' primary points of weakness are the operating mechanism and the bellows which is attached to the moving contact on the vacuum bottle (Figure 6-2). Due to the number of operations of some of our generator breakers, the bellows can start to crack which can impact the vacuum of the breaker. The operating mechanisms for vacuum circuit breakers are typically spring operated. This also simplifies the maintenance of these breakers."

    FIST 3-16, section 6.1.2, page 42, May 2024. Agency copy of FIST 3-16

    The current standard governs; this passage is a public-domain description of the practice dated May 2024.

  • FIST 3-16, section 6.2.4, page 44 (May 2024).
    Read the reference passage

    6.2.4 Insulation and Vacuum-integrity Test

    "A power factor or watt-loss test is not a test that will adequately test the insulation or the vacuum-integrity of a vacuum circuit breaker. A hi-pot test is required for this purpose."

    FIST 3-16, section 6.2.4, page 44, May 2024. Agency copy of FIST 3-16

    The current standard governs; this passage is a public-domain description of the practice dated May 2024.

  • FIST 3-16, section 6.3.2, page 46 (May 2024).
    Read the reference passage

    6.3.2 Insulation and Vacuum-integrity Test

    "An insulation test will check for possible shorts to ground. A vacuum-integrity test will check the pressure of the vacuum bottle. These tests are critical to the continued safe operation of the circuit breaker."

    FIST 3-16, section 6.3.2, page 46, May 2024. Agency copy of FIST 3-16

    The current standard governs; this passage is a public-domain description of the practice dated May 2024.

History

Every recorded change to this data record, oldest first.
DateChange
2026-10-29created

Cite this page

Cite the governing standard for the fact itself; cite this page as the finding aid.

"Data record tests.vacuum-interrupter-integrity.equipment.breaker-vacuum.maintenance." Circuit Breaker Reference. 2026-10-29. https://www.circuitbreakerreference.com/data/tests.vacuum-interrupter-integrity.equipment.breaker-vacuum.maintenance/.