IEC 60137 for Buyers: Scope, Tests and Reports
Use IEC 60137 for applicable complete AC bushings; confirm the edition, rating, type and routine tests, and report identifiers for the offered model.
Selection note: use this guide to compare technical requirements. Confirm catalog ranges, typical values and standard clauses against the model, edition and agreed test conditions; project acceptance follows the approved drawings and technical agreement.
On this page
- 01What does IEC 60137 cover and which edition applies?
- 02What is the difference between type tests and routine tests?
- 03How should buyers set a tan delta acceptance limit?
- 04How should partial-discharge acceptance be specified?
- 05How are cantilever load and temperature rise verified?
- 06Frequently asked questions
- 07Standards & sources
In short
IEC 60137 provides requirements for applicable complete AC bushings above 1 kV. Confirm the contracted edition, bushing type, ratings, test clauses and model report before accepting a quotation.
- Type tests prove the design once; routine tests are performed on every bushing before shipment.
- Agree tan delta conditions and limit by insulation type and contracted clause.
- PD limits apply at two voltage levels; ask suppliers for measured pC values, not just "pass".
- Altitude above 1000 m and heavy pollution require explicit correction in the bushing specification.
- A valid type test report must match the voltage, current, creepage and housing type ordered.
Use IEC 60137 for applicable complete AC bushings; specify the edition, insulation design, voltage class and matching type and routine reports.
01What does IEC 60137 cover and which edition applies?
IEC 60137 applies to complete bushings for AC systems above 1 kV. Buyers should agree the edition in the contract and check the clauses, tests and reports for the offered insulation type.
DC bushings are covered separately by IEC 65700-19-03, and interface dimensions for transformer bushings are given in EN 50180 / EN 50181 and in national standards such as GB/T 4109 in China. A complete specification normally cites IEC 60137 for performance plus one dimensional standard for interchangeability.
02What is the difference between type tests and routine tests?
Type tests are performed once on a representative bushing to prove a design, and include lightning and switching impulse, wet withstand, thermal stability, temperature rise, short-time current and cantilever load tests. Routine tests are performed on every bushing before delivery and verify manufacturing quality: capacitance and tan delta, dielectric withstand with partial discharge measurement, test tap insulation and tightness.
Buyers should check that the type test report covers the same design family: rated voltage, insulation type, housing material, creepage class and current rating. A report for a 126 kV porcelain bushing does not cover a 126 kV composite-housed version with a different flange.
- Routine: C1, C2 and tan delta at 10 kV and rising voltage.
- Routine: agree the dry power-frequency withstand voltage, duration and PD measurement conditions.
- Routine: test tap withstand, pressure or tightness test, visual and dimensional check.
- Type: lightning impulse 1.2/50 us, switching impulse for Um of 300 kV and above, wet tests for outdoor parts.
03How should buyers set a tan delta acceptance limit?
There is no single buyer-facing tan delta limit to apply to every bushing without checking the insulation type and test conditions. State the agreed voltage, temperature, measurement method and acceptance clause, then request the measured result for the exact model.
Compare tan delta at the agreed voltage and temperature with the contract limit, and retain the measured value and method in the model report.
04How should partial-discharge acceptance be specified?
Partial-discharge acceptance depends on the bushing construction, applied voltage and the contracted test clause. Specify each test point and permitted value, then ask for measured pC values and background noise on the model report.
Record applied voltage, duration, pC reading and background noise at every agreed PD test point.
| Test item | Contract input | Evidence to request | Review point |
|---|---|---|---|
| Tan delta | Insulation type, voltage, temperature and clause | Measured curve and limit | Model-specific result |
| Partial discharge | Applied voltage points and acceptance clause | Measured pC and background noise | Method and report ID |
| Temperature rise | Rated current and actual connection | Type-test temperature data | Material and thermal class |
| Cantilever load | Terminal load and mounting arrangement | Load test report | Class and duration |
| Impulse withstand | Specified insulation level | Waveform and test report | Applicable test clause |
| Tightness and tap | Design pressure and tap arrangement | Routine inspection record | Acceptance criteria |
| Identification | Model, rating and serial number | Nameplate and report traceability | Match the order |
“Buyer check: write the contracted edition, insulation type, test conditions and numerical acceptance clauses into the purchase specification.”
05How are cantilever load and temperature rise verified?
Cantilever and temperature-rise tests should be agreed for the rated current, connection and mechanical load class of the offered bushing. Confirm the loading method, duration, temperature reference and acceptance criteria from the applicable clause.
Specify Level II where heavy conductors, long spans or high short-circuit forces are expected, and add seismic qualification to IEC/TS 61463 or IEEE 693 in active seismic regions. Temperature rise must be verified at the actual connection type (draw lead, draw rod or bottom connection) because the conductor path dominates heating.
Applicable EONOVA Equipment
Conclusion
For an AC bushing, identify the applicable IEC 60137 edition and agree its model-specific type and routine evidence before order approval.
Talk to an EONOVA engineerFrequently Asked Questions
Is a type test report from another manufacturer acceptable?
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Do not treat a report from another manufacturer as automatic evidence for the offered design. Compare the tested and offered ratings, insulation construction, housing, manufacturing responsibility and contracted acceptance rules; request the supplier-specific evidence needed for approval.
How does altitude affect IEC 60137 test voltages?
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IEC 60137 assumes installation at or below 1000 m. Above that, external insulation must be designed with an altitude correction factor according to IEC 60071-2, which increases the required air-side withstand voltage and arcing distance. State the site altitude in the enquiry so the supplier can size the housing correctly.
What information should a routine test report contain?
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At minimum: serial number, C1 and C2 capacitance, tan delta at 10 kV and at rated voltage, applied withstand voltage and duration, measured PD in pC with background noise, test tap withstand result, tightness test result and the signature of the responsible test engineer.
Standards & Sources
- [1]IEC 60137:2017: Insulated bushings for alternating voltages above 1000 V
International Electrotechnical Commission (TC 36)
Supports: Scope, tan delta, PD, thermal and cantilever requirements summarised in this article.
- [2]IEC 60270: High-voltage test techniques: Partial discharge measurements
International Electrotechnical Commission (TC 42)
Supports: Calibration and background noise requirements for apparent charge (pC) measurement.
- [3]IEC 60060-1: High-voltage test techniques: General definitions and test requirements
International Electrotechnical Commission (TC 42)
Supports: Lightning (1.2/50 us) and switching impulse waveform definitions.
- [4]IEEE C57.19.00: General Requirements and Test Procedure for Power Apparatus Bushings
IEEE Standards Association
Supports: North American equivalent requirements used for dual-standard tenders.
Selection guidance for buyers. Confirm specifications and test evidence for the quoted model and supplying entity.
