Short answer: Use IEC 60840 for extruded AC cable systems with rated voltage U above 30 kV and up to 150 kV. Use IEC 62067 when rated voltage U is above 150 kV and up to 500 kV. A common 132 kV system therefore falls under IEC 60840, while a common 220 kV system falls under IEC 62067.
The decision must use the complete U0/U(Um) voltage designation and the current standard edition. It must not rely only on the words “high voltage,” “extra high voltage,” or on Um by itself. Both standards cover cables and accessories for extruded AC systems within their stated fixed-installation scope. Neither standard automatically covers HVDC, submarine designs, unusual installation conditions, route rating, sheath bonding, or every project-specific test.
The standards divide at rated voltage U = 150 kV
The title of IEC 60840 includes rated voltages above 30 kV up to and including 150 kV. Its maximum system-voltage range extends from Um = 36 kV to Um = 170 kV. IEC 62067 begins above 150 kV and reaches 500 kV rated voltage, with Um from 170 kV to 550 kV.
This creates an important boundary detail. Um = 170 kV appears in the published titles of both standards, but the rated-voltage condition is different. A system with U = 150 kV remains inside IEC 60840. A system with U above 150 kV moves into IEC 62067, even when the associated Um remains 170 kV.
For that reason, the specification should never state only “170 kV cable.” It should record U0, U, and Um. It should also define system grounding and operating duty because U0 depends on the voltage between conductor and earth or metallic screen.
| Voltage designation example | Rated voltage U | Typical IEC basis | Boundary note |
|---|---|---|---|
| 36/66(72.5) kV | 66 kV | IEC 60840 | Above the IEC 60502-2 range and within IEC 60840. |
| 64/110(123) kV | 110 kV | IEC 60840 | U remains below 150 kV. |
| 76/132(145) kV | 132 kV | IEC 60840 | A common transmission class within IEC 60840. |
| 150 kV rated, Um 170 kV | 150 kV | IEC 60840 | The upper inclusive boundary of IEC 60840. |
| Rated voltage above 150 kV, Um 170 kV | Above 150 kV | IEC 62067 | Use U, not Um alone, to resolve the boundary. |
| 127/220(245) kV | 220 kV | IEC 62067 | Above the IEC 60840 rated-voltage ceiling. |
| 290/500(550) kV | 500 kV | IEC 62067 | The upper inclusive boundary of IEC 62067. |
IEC 60840 and IEC 62067 share a system approach
Both documents address power cable systems with extruded insulation and their accessories. This point matters. A compliant cable length does not by itself establish compliance for the complete circuit. Joints and terminations create new electrical, material, thermal, sealing, and mechanical interfaces.
IEC 60840 explicitly specifies requirements for power cable systems, cables alone, and accessories alone. It applies to single-core cables and individually screened three-core cables, together with their accessories, under usual fixed-installation and operating conditions.
IEC 62067 addresses extruded cable systems and accessories in its higher voltage range. Its stated scope applies to single-core cables and their accessories under usual fixed-installation and operating conditions. It does not provide a general three-core EHV cable route equivalent to the three-core provision stated in IEC 60840.
CIGRE’s accessory-interface work reinforces the system principle. A joint or termination must remain compatible with the cable electrically, thermally, materially, and thermomechanically. A common nominal voltage is not sufficient evidence.
The two standards are related, but they are not interchangeable
| Scope question | IEC 60840 | IEC 62067 |
|---|---|---|
| Rated AC voltage U | Above 30 kV through 150 kV inclusive. | Above 150 kV through 500 kV inclusive. |
| Published Um range | 36 kV through 170 kV. | 170 kV through 550 kV. |
| Insulation family | Extruded insulation. | Extruded insulation. |
| Cable form in stated scope | Single-core and individually screened three-core. | Single-core. |
| Accessories | Included as cable-system, cable-alone, and accessory-alone requirements. | Included with the cable system. |
| Installation context | Fixed installation under usual conditions. | Fixed installation under usual conditions. |
| Special submarine design | May need modified tests or special test conditions. | May need modified tests or special test conditions. |
| Extruded HVDC | Outside scope. | Outside scope. |
| Transition joint to paper insulation | Not covered. | Not covered. |
The current IEC record for 60840 includes the 2020 base edition, Amendment 1:2023, and a 2025 corrigendum. The official IEC publication record should be checked when the contract freezes the edition. IEC 62067:2022 is edition 3.0 on the current IEC record.
An old datasheet that states only “IEC 60840” or “IEC 62067” leaves an avoidable gap. The project should identify edition, amendment or consolidated version, corrigenda, language where relevant, and any national adoption.
What the standards test—and what each evidence layer means
Standard compliance is not one test certificate. The evidence develops through several layers. Each layer answers a different question, and the applicable clauses depend on the selected standard and design.
Prequalification evidence addresses long-term system behavior
Prequalification testing evaluates a cable system over extended thermo-electrical duty before general commercial application of the design family. It involves cable and representative accessories. Its value lies in the defined design envelope, not only in a pass statement.
A project review should identify the tested voltage class, conductor and insulation design, accessories, materials, dimensions, test arrangement, and any extension rules used for the offered system. A substantial change cannot be assumed to remain covered without technical assessment.
Type tests verify a defined system design
Type tests subject the selected cable and accessory system to specified electrical and non-electrical duties. The evidence belongs to the tested design and its permitted range. It does not prove every future material, dimension, conductor, sheath, joint, or termination combination.
Routine tests check manufactured output
Routine tests apply to manufactured cable lengths and accessories as required by the standard. They check production output against defined electrical or construction requirements. They do not repeat the long-term purpose of prequalification or the broader design purpose of type tests.
Sample tests verify selected production characteristics
Sample tests examine specified characteristics on samples selected from production. The inspection and test plan should define frequency, selection, witness points, records, and acceptance handling.
After-installation tests address the assembled circuit
Transport, pulling, cable preparation, jointing, termination assembly, sheath bonding, and civil interfaces occur after factory tests. After-installation testing provides evidence on the installed system within the selected method’s capability. CIGRE TB 841 notes that test-source technology, route length, voltage, and test burden require technical consideration rather than casual substitution.
IEC 62067 does not simply mean “the same tests at a higher voltage”
Higher voltage increases electric-field and accessory-interface demands. IEC 62067 also operates in a system range where large conductors, thick insulation, long qualification programs, large drums, and complex site interfaces become common. The specification must treat the offered cable and accessories as one qualified family.
The difference therefore extends beyond test voltage. Design changes can affect field stress, thermal gradients, conductor geometry, insulation processing, degassing, metallic sheath, accessory dimensions, installation forces, and qualification coverage. A 132 kV design cannot be scaled into a 220 kV design by adding insulation thickness.
The XWA 132 kV cable page provides product context for a common IEC 60840 class. The XWA 220 kV cable page provides the corresponding IEC 62067 product context. Neither page replaces the project-specific qualification and test schedule.
Five situations require more than the base standard
1. Submarine or other special cable systems
Both official scopes state that special cables such as submarine designs may require modifications to standard tests or special test conditions. Armor, dynamic duty, water pressure, installation tension, repair joints, factory joints, long delivery lengths, and vessel interfaces can add requirements outside a normal land-cable basis.
2. Unusual land routes
Deep crossings, tunnels, shafts, bridges, severe thermal zones, long ducts, flood exposure, chemical contamination, or high mechanical forces can require additional design evidence. The related XWA article on underground route constraints explains why one restrictive segment can govern the complete circuit.
3. GIS, transformer, and outdoor termination interfaces
The termination must match the connected equipment, insulation system, mechanical loads, pressure or sealing boundary, pollution conditions, and dimensional interface. IEC 60840 also links certain gas-immersed terminations above its stated threshold to IEC 62271-209 requirements. The contract must capture all applicable documents.
4. Fire, smoke, water, and environmental declarations
Base compliance does not make every cable low-smoke, halogen-free, flame-retardant, fire-resistant, radially watertight, or suitable for every chemical environment. Declared performance needs the relevant materials, construction, test methods, and project acceptance criteria.
5. National grid and utility requirements
A utility specification may add conductor constructions, insulation-stress limits, metallic sheath duties, bonding, quality plans, witness points, diagnostic tests, spares, documentation, installation controls, or acceptance rules. These additions should complement the IEC basis without silently changing its scope.
Neither IEC 60840 nor IEC 62067 completes the cable design
The standards define test methods and requirements within their scopes. They do not supply one universal cable construction or one universal current rating. A complete design also needs system and route inputs.
- Voltage duty: U0/U(Um), frequency, grounding, impulse duty, temporary overvoltage, and switching conditions.
- Conductor duty: continuous load, cyclic load, emergency duration, short-circuit current, losses, and voltage drop.
- Thermal route: installation method, ambient temperature, soil or backfill data, duct arrangement, depth, spacing, and adjacent heat sources.
- Metallic system: fault-current area, sheath material, water barrier, bonding, earth continuity, link boxes, and sheath voltage limiters.
- Mechanical route: drum length, mass, bending, pulling tension, sidewall pressure, supports, movement, and accessory loads.
- Environment: water paths, corrosion, fire, smoke, ultraviolet exposure, chemicals, flooding, and contamination.
- Evidence: qualification range, type tests, routine and sample tests, inspections, site records, and after-installation tests.
IEC 60183 provides selection guidance for extruded AC cable systems. IEC 60287 and IEC 60853 provide current-rating methods for steady and cyclic or emergency conditions. Other standards can apply to conductors, oversheaths, impulse methods, terminations, fire performance, or equipment interfaces. The cable-system specification should show how these documents interact.
A six-step standard-selection check
- Confirm AC or DC duty. IEC 60840 and IEC 62067 are AC extruded-system standards. Extruded HVDC requires a different qualification basis.
- Record U0/U(Um). Do not select from a shorthand voltage or from Um alone.
- Use rated voltage U. U up to 150 kV selects IEC 60840; U above 150 kV through 500 kV selects IEC 62067.
- Check construction scope. Confirm single-core or three-core, extruded insulation, cable accessories, and transition-joint requirements.
- Check installation scope. Identify submarine, unusual route, equipment interface, environmental, and utility additions.
- Freeze the evidence basis. State edition, qualification family, type tests, production tests, witness points, after-installation tests, and change-control rules.
A specification statement should be precise
A weak statement reads: “Cable shall comply with IEC 62067.” It does not define voltage, edition, cable system, accessories, route, evidence, or project additions.
A stronger form reads:
The complete 127/220(245) kV extruded AC cable system, including the scheduled joints and terminations, shall comply with IEC 62067:2022 within its applicable scope. The offered design shall identify its prequalification and type-test envelope. Routine, sample, inspection, documentation, and after-installation requirements shall follow the approved project specification. Route, bonding, water, fire, equipment-interface, and national utility additions remain separately applicable.
This wording is an illustrative structure, not a universal project clause. The final specification must use the actual voltage, standard edition, cable system, accessories, installation, and acceptance requirements.
Questions about IEC 60840 and IEC 62067
Does a 150 kV cable use IEC 60840 or IEC 62067?
IEC 60840 includes rated voltage U up to and including 150 kV. IEC 62067 begins above 150 kV. The complete U0/U(Um) designation and contract edition should still be stated.
Why does Um = 170 kV appear in both standard titles?
It sits at the adjoining maximum system-voltage boundary. The rated-voltage condition resolves the selection: U at 150 kV remains in IEC 60840, while U above 150 kV moves into IEC 62067.
Does IEC 62067 cover three-core EHV cable?
Its published scope states single-core cables and their accessories. A proposed three-core or special design requires a separately defined technical and test basis rather than an assumption of ordinary scope coverage.
Do these standards cover submarine cable?
Not as ordinary special-cable scope. Both official summaries state that submarine cables can require modified standard tests or specially devised conditions. The submarine project basis must add route, mechanical, water, armor, joint, installation, and repair requirements.
Does a type-test report prove the complete project system?
Not by itself. The report must match the offered cable and accessory design within its permitted range. Prequalification, production tests, accessory installation, site controls, and after-installation evidence answer different questions.
Can IEC 60840 or IEC 62067 be used for HVDC?
They define extruded AC cable-system requirements. HVDC field distribution, polarity duty, converter transients, materials, accessories, and qualification need a dedicated DC basis such as the applicable IEC or CIGRE framework.
Engineering conclusion
The IEC 60840 versus IEC 62067 decision is straightforward only after the voltage is written correctly. IEC 60840 covers extruded AC systems above 30 kV through 150 kV rated voltage. IEC 62067 covers the range above 150 kV through 500 kV. The shared Um = 170 kV boundary does not replace rated voltage U.
Correct standard selection is only the first step. The project must also define cable form, accessories, route, environmental duty, equipment interfaces, qualification range, production tests, installation controls, site tests, edition, and additions. Compliance belongs to the defined cable-and-accessory system and its traceable evidence.
Submit the HV Standards Design Basis
For a standards-scope review, provide U0/U(Um), AC or DC duty, grounding, conductor and insulation design, single-core or three-core arrangement, route and installation method, joint and termination interfaces, metallic sheath and bonding concept, environmental declarations, applicable IEC edition, qualification evidence, required tests, documentation, quantity, and destination. XWA Power & Cable can align the proposed cable-system construction and evidence schedule with the approved specification; final capability confirmation follows the complete project basis.