Reference designations identify an object within a structured system. Good tags express function, product and location consistently enough that drawings, labels, software and maintenance records refer to the same object.
Learning objectives
Build a project designation strategy, separate aspect prefixes and avoid tag schemes that collapse when panels or functions are repeated.
Core engineering principles
An object can have several aspects
Function, product and location describe different views. Combining them without a rule produces long, inconsistent or ambiguous tags.
Hierarchy creates uniqueness
Plant, switchboard, panel, function and device levels should form a predictable path. Repeated feeder designs then remain locally readable and globally unique.
Designation is not merely a label format
The structure supports document navigation, data exchange and automated reports. Changing it late affects every downstream artifact.
Software and physical labels must match
Relay names, SCADA points, terminal markers and equipment labels should derive from the approved designation model.
Customer conventions require mapping
A project may mandate legacy tags. A controlled mapping can preserve customer identifiers while retaining internal object structure.
Engineering application method
- Step 1: Define system and location hierarchy.
- Step 2: Choose permitted aspect prefixes and abbreviation rules.
- Step 3: Create examples for typical feeder, relay, terminal and cable objects.
- Step 4: Validate uniqueness across repeated panels.
- Step 5: Freeze and publish the designation guideline.
Practical example
A relay tagged only K1 is understandable inside one sheet but ambiguous across 20 panels. A structured designation ties it to the panel and function without manually inventing new numbers.
Common mistakes
- Using device sequence alone.
- Mixing location and function characters.
- Changing tags after manufacturing begins.
- Allowing PLC and drawings to use different names.
- Creating exceptions without governance.
Design and review checklist
- Is every object unique?
- Can repeated panels reuse a pattern?
- Are aspect meanings documented?
- Do labels and software match?
- Is customer mapping controlled?
Standards basis and official sources
- IEC 81346-1:2022 — Structuring principles and reference designations.
- IEC 61082-1:2014 — Preparation of electrotechnical documents.
Engineering note: Verify the contracted standard edition, amendments, manufacturer evidence and project-specific studies before applying these principles to a supplied assembly.