Common letters (IEC 81346-2, companion standard):
| Letter | Class | Example | |--------|-------|---------| | B | Transducer (sensor) | B1 (pressure sensor) | | C | Capacitor | C101 | | F | Protection device | F1 (fuse) | | K | Relay, contactor | K1 | | M | Motor | M1 | | Q | Circuit breaker | Q1 | | R | Resistor | R1 | | S | Switch (manual) | S1 (pushbutton) | | T | Transformer | T1 | | V | Semiconductor | V1 (diode) | | X | Terminal, connector | X1 (terminal block) | iec 61346-1 pdf
| Mistake | Why it’s wrong | Correct way |
|---------|----------------|-------------|
| Mixing aspects without prefixes | M1 could be motor or function | -M1 for product, =M1 for function |
| Using numbers without letter class | 1 means nothing | -M1 (motor 1) |
| Changing aspect mid-drawing | Confusion | Pick one main aspect per document, use others as needed |
| Forgetting that it replaced IEC 61346-1 | Using an obsolete reference | Cite IEC 81346-1:2009 or later | Common letters (IEC 81346-2, companion standard): | Letter
(Note: numeric ranges reflect typical industry reports and pilot project results; outcomes vary by organization.) Common letters (IEC 81346-2
Connect Everything, Work Anywhere
