Cable derating
Cable derating meaning in Australian current-carrying capacity records.
Derating in current-carrying records
Cable derating is the record term used when installation conditions change how a cable current-carrying capacity value is used. In Australian cable work it usually belongs beside metric cable size, installation method, ambient condition, grouping and the data source for the base value.
AUWiring treats derating as a context record. It does not publish controlled AS/NZS 3008 factors in the glossary and does not decide the final cable selection.
Conditions that can change the usable value
A derating record should show which condition changed the value and where that condition came from. A single derating label without the installation context is too thin for later review.
| Record context | Keep visible | Why it matters |
|---|---|---|
| Installation condition | method, enclosure, burial, tray or grouping note | Shows why the base cable value changed |
| Temperature or grouping basis | entered factor or licensed data source | Keeps controlled data outside generic copy |
| Cable worksheet | base value, adjusted value and cable candidate | Separates the record from final selection |
Derating is separate from voltage drop
Derating and voltage drop are both cable checks, but they answer different questions. Derating affects usable current-carrying capacity. Voltage drop reviews voltage lost over a route.
A cable may need both records visible before the project can move into a stronger cable review. This glossary entry only explains the term and the fields that should travel with it.
Using derating factors
Use the cable-size calculator with entered current-carrying capacity data. Use the derating guide when the project needs a clear record of installation conditions without copying controlled table values into public text.
Source and review
Check the terminology source, review timing and Australian application before carrying this term into a project record.
| Item | Value |
|---|---|
| Source | AUWiring cable derating article, cable-size calculator wording and cable derating guide content. |
| Source type | Australian terminology |
| Derivation basis | AUWiring Australian glossary term; no controlled AS/NZS 3008 table values are reproduced. |
| Last checked | 2026-07-13 |
| Review interval | Annual terminology review or sooner if cable derating wording changes. |
| Review trigger | Update when cable derating article, cable-size calculator or guide wording changes. |
| Version used | T34-2026-07-13 |
| Australian application | Australia; Australian English cable terminology. |