Cable derating without table copying
A workflow guide for recording cable derating sources and assumptions without turning AUWiring into a copied cable-table service.
Derating record purpose
Derating is the step that connects a cable candidate to its real installation context. The conductor label alone does not decide current-carrying capacity. Installation method, grouping, ambient conditions, insulation, enclosure conditions and source documents can all change the value used in the calculator.
This guide keeps the workflow visible without reproducing controlled cable-selection tables. The calculator accepts the reviewed current-carrying capacity as a user-entered value.
Workflow
- Identify the cable candidate and metric label.
- Identify the source used for current-carrying capacity.
- Record the installation method and environmental assumptions.
- Record any grouping, ambient or enclosure factors that affect the value.
- Enter the reviewed current-carrying capacity into the cable-size calculator.
- Keep the derating source note with the result before checking voltage drop or protection.
Derating source record
| Field | Record | Why it matters |
|---|---|---|
| Cable label | Metric size, conductor material and cable family | Prevents capacity values being applied to the wrong cable |
| Source document | Standard, design record, manufacturer data or reviewed schedule | Shows where the capacity came from |
| Installation basis | Enclosure, conduit, tray, buried, air or other method | Current-carrying capacity depends on installation |
| Environmental basis | Ambient, grouping and heat conditions | Derating factors can change the usable current |
| Entered capacity | Final current-carrying capacity in A | This is the value the calculator compares |
| Reviewer note | Assumptions and unresolved checks | Keeps the worksheet from sounding like final approval |
Calculator handoff
Use the cable-size calculator after the derating value is known. The cable-size calculator compares entered load current with entered current-carrying capacity and voltage-drop data. It does not derive the derated value from the cable label alone.
If the current margin is acceptable but voltage drop is not, continue with voltage-drop review. If voltage drop is acceptable but current-carrying capacity is not, return to the derating source and candidate selection.
Boundaries
- Do not infer current-carrying capacity from a metric label alone.
- Do not copy table values into public page copy.
- Do not hide derating assumptions inside a final amp value.
- Do not describe a calculator comparison as installation approval.