Updated on: 13.02.2022

Equipment labelling and standardisation

Subject area

Service Engineering | Systems Engineering

Equipment marking and classification

Equipment marking and classification according to IEC 81346 and their significance for service and maintenance.

Marking of electrical equipment

An electrical system or installation can consist of a wide variety of components, complete assemblies or entire devices. The obligation to label equipment is part of the regular inspection in accordance with the DGUV regulation 3 of the employers' liability insurance association. In sum, all electrical systems and equipment must be inspected and labelled. Especially for practitioners who are entrusted with the preparation of circuit diagrams, knowledge of the current structure and layout of the equipment marking is essential.

What is EN 81346?

The basis for the classification of equipment is the standard EN 81346. This standard describes the structuring principles and reference marking and is divided into two parts:

  • EN 81346-1: General rules
  • EN 81346-2: Classification of objects and coding of classes

What is the procedure for equipment labelling (EN 81346-1)?

The first part provides an overview of how to proceed in the context of equipment identification. The elements object, aspect, structure and reference indicator explained here can be applied to all maintenance objects that are the subject of maintenance and repair activities and can also be used for structuring maintenance contracts.

The object is the physical object that is to be marked. In this context, the standard also speaks of a unit of observation. Depending on the life cycle phase (construction, installation, maintenance ...), the structure or the depth of consideration can of course vary. It is important that all safety and maintenance-relevant properties can be recorded.

The aspect is describes the way in which information or the object itself is selected. Accordingly, the specific aspect is the purpose of the equipment marking. Three essential aspects can be primarily distinguished:

  • Functional aspect (What?)
  • Product aspect (How?)
  • Aspect of place (Where?)

Structure is understood to mean the factual logical structure and interrelationships of the technical system. Which component belongs to which assembly. This is usually mapped using structural parts lists. However, it is not always the case that the viewpoint of the design corresponds to the maintenance viewpoint.

  • Functional structure (cf. functional model)
  • Product-related structure (cf. bill of materials)
  • Site-related structure (cf. site plan)

The reference marking finally documents the previous considerations on the structure and aspects of the system and is therefore the actual marking.

Depending on the aspect, the different signs are assigned.

  • ( = )for function
  • ( - ) for product
  • ( + )for place

How are the objects classified and which mark is to be applied (EN 81346-2)?

The second part of the standard in particular is relevant for the actual implementation of equipment labelling and provides information on which identification letters are to be applied. These were taken from DIN 6779-2, which has since been withdrawn and thus only EN 81346 is still valid.

Tables of the main subclasses

The labelling scheme is divided into two or, in the meantime, three levels of classification. The main classes A - Z, whereby X and Y have not yet been assigned. Each main class in turn has several subclasses. The decisive criterion for differentiation is the task of the object within the system. It should be noted, however, that the standard has been available in a new version since 2019 or 2020 and therefore the current version should be used. Compared to the predecessor, some classes have been deleted or added and the idea of assignment has also changed a little. For example, classes A and V have been deleted. Through the introduction of the 3rd outline level, a much more detailed differentiation is now possible. However, this also makes working with the standard somewhat more complex.

Application of EN 81346 in systems engineering, maintenance and service

The task of systems engineering is to design and describe technical systems, their functions and interdependencies. If the focus is primarily on service functions, as in the case of technical services, we can also speak of service engineering in this context. Efficient service and maintenance processes require not only a clear identification of the maintenance object, but also a structured maintenance and service organisation.

For this reason, the maintenance and service sector should also deal intensively with equipment identification in accordance with EN 81346 and map equipment structures accordingly. Particularly in view of the fact that sensors are becoming increasingly important in predictive and data analysis-based maintenance strategies.

Mapping of equipment identification in software systems

It should be ensured that the equipment identification is also mapped in the same way in all software systems and applications used.

  • PLM system: The PLM application should ideally be the single point of truth
  • Design applications: It should be possible to maintain current information here, which can then be found in the PLM system.
  • Maintenance software: It should be possible to add asset-specific information in the maintenance software and CMMS.

Sources:

  • https://www.beuth.de/de/norm/din-en-iec-81346-2/320735342 - retrieved on: 16.01.2022