Electrical installation characteristics

D - MV & LV architecture selection guide

Electrical installation characteristics

These are the main installation characteristics enabling the defining of the fundamentals and details of the electrical distribution architecture. For each of these characteristics, we supply a definition and the different categories or possible values.

Activity

Definition:

Main economic activity carried out on the site.

Indicative list of sectors considered for industrial buildings:

• Manufacturing
• Food & Beverage
• Logistics

Indicative list of sectors considered for tertiary buildings:

• Offices buildings
• Hypermarkets
• Shopping malls

Site topology

Definition:

Architectural characteristic of the building(s), taking account of the number of buildings, number of floors, and of the surface area of each floor.

Different categories:

• Single storey building,
• Multi-storey building,
• Multi-building site,
• High-rise building.

Layout latitude

Definition:

Characteristic taking account of constraints in terms of the layout of the electrical equipment in the building:

• aesthetics,
• accessibility,
• presence of dedicated locations,
• use of technical corridors (per floor),
• use of technical ducts (vertical).
  

Different categories:

•  Low: the position of the electrical equipment is virtually imposed
• Medium: the position of the electrical equipment is partially imposed, to the detriment of the criteria to be satisfied
• High: no constraints. The position of the electrical equipment can be defined to best satisfy the criteria.

Service reliability

Definition:

The ability of a power system to meet its supply function under stated conditions for a specified period of time.

Different categories:

• Minimum: this level of service reliability implies risk of interruptions related to constraints that are geographical (separate network, area distant from power production centers), technical (overhead line, poorly meshed system), or economic (insufficient maintenance, under-dimensioned generation).
• Standard
• Enhanced: this level of service reliability can be obtained by special measures taken to reduce the probability of interruption (underground network, strong meshing, etc.)
  

Maintainability

Definition:

Features input during design to limit the impact of maintenance actions on the operation of the whole or part of the installation.

Different categories:

• Minimum: the installation must be stopped to carry out maintenance operations.
• Standard: maintenance operations can be carried out during installation operations, but with deteriorated performance. These operations must be preferably scheduled during periods of low activity. Example: several transformers with partial redundancy and load shedding.
• Enhanced: special measures are taken to allow maintenance operations without disturbing the installation operations. Example: double-ended configuration.

 

Installation flexibility

Definition:

Possibility of easily moving electricity delivery points within the installation, or to easily increase the power supplied at certain points. Flexibility is a criterion which also appears due to the uncertainty of the building during the pre-project summary stage.

Different categories:

• No flexibility: the position of loads is fixed throughout the lifecycle, due to the high constraints related to the building construction or the high weight of the supplied process. E.g.: smelting works.
• Flexibility of design: the number of delivery points, the power of loads or their location are not precisely known.
• Implementation flexibility: the loads can be installed after the installation is commissioned.
• Operating flexibility: the position of loads will fluctuate, according to process re-organization.

Examples:
    - industrial building: extension, splitting and changing usage
    - office building: splitting