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 (see 5.1)
 Environmental impact  Minimal: compliance with European standard regulations
 Preventive maintenance costs  Standard (see 5.3)
 Power supply availability  Pier 1 (see 5.4)

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
DB422144 EN.svg

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


DB422145 EN.svg

Fig. D32 : Detailed single-line diagram (1 substation based on fig.D22)


DB422146 EN.svg

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 L for more information), presence of harmonics LV automatic compensation (without detuned reactor).


ru:Пример: электроснабжение типографии zh:举例:印刷厂的电气装置

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