Example: electrical installation in a printworks

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Brief description

Printing of personalized mailshots intended for mail order sales.

Installation characteristics

Characteristic Category
Activity Mechanical
Site topology single storey building 10000m2 (8000m2 dedicated to the process, 2000m2 for ancillary areas)
Layout latitude High
Service reliability Standard
Maintainability Standard
Installation flexibility
  • No flexibility planned:
    • HVAC
    • Process utilities
    • Office power supply
  • Possible flexibility:
    • finishing, putting in envelopes
    • special machines, installed at a later date
    • rotary machines (uncertainty at the draft design stage)
Power demand 3500kVA
Load distribution Intermediate distribution
Power interruptions sensitivity
  • Sheddable circuits:
    • offices (apart from PC power sockets)
    • air conditioning, office heating
    • social premises
    • maintenance premises
  • long interruptions acceptable:
    • printing machines
    • workshop HVAC (hygrometric control
    • Finishing, envelope filling
    • Process utilities (compressor, recycling of cooled water)
  • No interruptions acceptable:
    • servers, office PCs
Disturbance sensitivity
  • Average sensitivity:
    • motors, lighting
  • High sensitivity:
    • IT

No special precaution to be taken due to the connection to the EdF network (low level of disturbance)

Disturbance capability Non disturbing
Other constraints
  • Building with lightning classification: lightning surge arresters installed
  • Power supply by overhead single feeder line

Technological characteristics

Criteria Category
Service conditions
  • IP: standard (no dust, no water protection)
  • IK: standard (use of technical pits, dedicated premises)
  • °C: standard (temperature regulation)
Required service index 211
Offer availability by country No problem (project carried out in Europe)
Other criteria Not applicable

Architecture assessment criteria

Criteria Category
On-site work time Standard
Environmental impact Minimal: compliance with European standard regulations
Preventive maintenance costs Standard
Power supply availability Tier 1

Step 1: Architecture fundamentals

Choice Main criteria Solution
Connection to upstream network Isolated site, 3500 kVA MV single-line service
MV Circuits Layout + criticality single feeder
Number of transformers Power > 2500kVA 2 x 2000kVA
Number and distribution of substations Surface area and power distribution 2 possible solutions: 1 substation or 2 substations
  • if 1 substations: Normaly open bus-coupler between MLVS
  • if 2 substations: Main LV switchboard interconnected by a busway
MV Generator Site activity No
Fig. D31 – Two possible single-line diagrams

Step 2: Architecture details

Choice Main criteria Solution
Layout Service conditions Dedicated premises
LV circuit configuration 2 transformers, requested by the power demand Solution from fig.D22 or D23 are possible
Centralized or distributed layout Uniform loads, distributed power, scalability possibilities

Non-uniform loads, direct link from MLVS

  • Decentralized with busbar trunking:
    • finishing sector, envelope filling
  • Centralized with cables:
    • special machines, rotary machines, HVAC, process utilities, offices (2 switchboards), office air conditioning, social premises, maintenance
Presence of back-up generator Criticality ≤ low

Network availability: standard

No back-up generator
Presence of UPS Criticality UPS unit for IT devices and office workstations
Fig. D32 – Detailed single-line diagram (1 substation based on fig.D22)
Fig. D33 – Detailed single-line diagram (2 substation based on fig.D24)

Choice of technological solutions

Choice Main criteria Solution
MV/LV substation Service conditions indoor (dedicated premises)
MV switchboard Offer availability by country SM6 (installation in Europe)
Transformers Service conditions cast resin transfo (avoids constraints related to oil)
LV switchboard Service conditions, service index for LV switchboards MLVS: Prisma P

Sub-distribution: Prisma

Busway Load distribution Canalis KS (fig.D32 or D33)

Canalis KT for main distribution (fig D33)

UPS units Installed power to be supplied, back-up time Galaxy PW
Power factor correction Reactive power to provide for the minimum up to the full load without harmonic (see chapter Power Factor Correction for more information), presence of harmonics LV automatic compensation (without detuned reactor).