Which circuits should be visible?
Use the project logic, device schedule and terminal information to trace the circuit paths.
| Circuit | Reference |
|---|---|
| Trip | Approved logic |
| Close | Permissive and interlock |
| Indication | Status and alarm |
| Test | Approved procedure |
Sources: International Electrotechnical Commission: IEC 60617 Graphical Symbols for Diagrams
Who approves the content?
The responsible registered engineer approves the protection and control design. The drafter checks that supplied inputs are represented consistently.
Common questions
What else should the bid team know?
Is a protection schematic a protection study?
No. It is a drawing of approved circuits and interfaces.
Can a drafter choose a relay setting?
No. Settings and design decisions stay with the responsible engineer.
What if the logic is incomplete?
Record the open input and route it to the responsible reviewer.
Primary sources
- IEEE C2-2023 National Electrical Safety CodeIEEE Standards Association
- IEC 61936-1:2021International Electrotechnical Commission
- IEC 60617 Graphical Symbols for DiagramsInternational Electrotechnical Commission
- 29 CFR 1910.269Occupational Safety and Health Administration