DEMO — fictional range. Local brief only, NOT SENT. No personal data is collected or transmitted.
REVISION
A revision to a bracket is a revision to a calculation.
Balance-of-system drawings are the output of a load and thermal calculation. Changing the drawing without re-running it is how a compliant design becomes a non-compliant one.
- Revision letter
- Every change, however small, gets one
- What changed
- The feature, the value and the reason
- Calculation impact
- Whether the load or thermal case has to be re-run
- When it took effect
- Which batch or which site first used it
- What it supersedes
- Which revision the new one replaces
- As-built
- Whether the installation matches the drawing that was calculated
| Rev | Change | Reason | Calculation |
|---|---|---|---|
| A | Vent area increased 20 percent | Enclosure ran above the cell limit | Thermal re-run |
| B | Stand-off raised to 120 mm | Inverter derating against the wall | Thermal re-run |
| C | Support centres reduced to 1100 mm | Cable load higher than assumed | Load re-run |
Why the as-built column belongs on the log.
Because the calculation describes the drawing, not the roof. If the installer moved a fixing to avoid an obstruction, the installation no longer matches what was calculated and nobody knows unless it is recorded.
The habit worth copying.
Recording which revision each site was built to. Without it, a question about an installed system cannot be answered from the file.