Transformer impedance context
Transformer impedance and source-data fields for Australian transformer current and short-circuit worksheets.
Transformer impedance fields for fault-current checks
Record transformer source fields without turning the table into a fault study or transformer selection guide.
| Field | Purpose | Typical source | Boundary |
|---|---|---|---|
| Transformer kVA | Sets apparent-power basis for current estimates. | Nameplate, schedule or utility data | Use the correct transformer and winding context. |
| Primary and secondary voltage | Defines which side of the transformer is being calculated. | Nameplate or design record | Line-to-line and phase-to-neutral values must not be mixed. |
| Impedance percent | Supports short-circuit estimates where used. | Transformer nameplate or manufacturer data | Network impedance and upstream source can change the result. |
| Source fault level | Records utility or study value where available. | DNSP, utility or engineering study | A missing source level should not be guessed. |
| Connection and earthing context | Keeps vector group or earthing notes visible where relevant. | Product data or project study | This table does not interpret protection coordination. |
- Use this table to keep transformer assumptions traceable.
- Fault-current and protection decisions need source studies, device data and competent review.
Before transformer data feeds fault calculations
Capture transformer rating, impedance and supply assumptions before using them in fault-current or downstream protection checks.
| Item | Value |
|---|---|
| Purpose | Record transformer source fields without turning the table into a fault study or transformer selection guide. |
| How to use the source | Field table only; transformer current and short-circuit arithmetic lives on calculator and chart pages. |
| Standards and project context | Australian project context; transformer product data, utility data and project requirements govern formal studies. |
| Where judgement is still needed | Use this table for lookup, labelling or worksheet context; do not treat it as a project-specific calculation result. |
| Before relying on it | Confirm current standards, local authority requirements, DNSP conditions, project documents and manufacturer data before relying on a decision. |
Product record basis for transformer data
Keep the transformer record, checked date and project connection context visible beside each impedance field.
| Item | Value |
|---|---|
| Source | AUWiring transformer current and short-circuit calculator field models. |
| Source type | Project or product record model |
| Derivation basis | AUWiring source-field table for transformer records; transformer selection and protection studies are not reproduced. |
| Last checked | 2026-07-13 |
| Review interval | Annual or when transformer calculators, impedance wording or product-data practice changes. |
| Review trigger | Calculator field change, product-data convention change, source-study change or project feedback. |
| Version used | R25-2026-07-13 |
| Australian application | Australia; utility data, transformer product data, project documents and competent review govern final use. |