Breaking capacity
Breaking capacity meaning in Australian protective-device and fault-current records.
Breaking capacity on device data
Breaking capacity is protective-device rating context related to interrupting fault current. In Australian switchboard and circuit records it is usually written beside a device type such as MCB, MCCB, fuse or RCBO and compared with the prospective fault-current context for that location.
The term belongs with product data. It should not be guessed from the normal current rating or copied from a similar device without checking the actual record.
What it is compared with
Breaking-capacity review needs both sides of the comparison: the device data and the prospective short-circuit current at the device location.
| Record context | Keep visible | Why it matters |
|---|---|---|
| Protective device | device type, model or schedule reference | Shows which product data is being read |
| Fault-current basis | location and prospective current in kA | Keeps the comparison tied to the point reviewed |
| Product review | manufacturer data and project requirements | Prevents the glossary term from acting as a product decision |
Current rating is different
Breaking capacity is not the same as ordinary load current rating. A device can have one record for normal current duties and another for fault-interruption context.
It also does not cover selectivity, cascading, coordination, switchboard rating or installation suitability. Those topics need manufacturer data and project review, not just the abbreviation or a copied kA value.
Using breaking-capacity checks
Use the short-circuit current calculator to prepare an entered fault-current estimate. Use the protection device terms table to keep device wording clear, and use manufacturer-data guidance when the product rating controls how the record is interpreted.
Source and review
Check the terminology source, review timing and Australian application before carrying this term into a project record.
| Item | Value |
|---|---|
| Source | AUWiring protection device terms table, short-circuit calculator wording and protection guide content. |
| Source type | Australian terminology |
| Derivation basis | AUWiring Australian glossary term; no controlled protection tables are reproduced. |
| Last checked | 2026-07-13 |
| Review interval | Annual terminology review or sooner if protection device wording changes. |
| Review trigger | Update when device terms, short-circuit calculator or manufacturer-data guide wording changes. |
| Version used | T25-2026-07-13 |
| Australian application | Australia; Australian English protection terminology. |