Example: electrical installation in a printworks

Printing of personalized mailshots intended for mail order sales.

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

Criteria	Category
Atmosphere, environment	IP: standard (no dust, no water protection) IK: standard (use of technical pits, dedicated premises) °C: standard (temperature regulation)
Service index	211
Offer availability by country	No problem (project carried out in France)
Other criteria	Nothing particular

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

Choice	Main criteria	Solution
Connection to network	Isolated site	single branch circuit
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: NO link between MLVS if 2 substations: interconnected switchboards
MV Generator	Site activity	No

Fig. D29: Two possible single-line diagrams

“1 substation” solution

Choice	Main criteria	Solution
Layout	Atmospheric constraint	Dedicated premises
Centralized or decentralized 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 servers and office PCs
LV circuit configuration	2 transformers, possible partial redundancy	Two-pole, variant 2 ½ MLVS + NO link (reduction of the Isc by MLVS, no redundancy process (≤ weak) sheddable circuit for non-critical loads

Fig. D30: Detailed single-line diagram (1 substation)

Choice	Main criteria	Solution
MV/LV substation	Atmosphere, environment	indoor (dedicated premises)
MV switchboard	Offer availability by country	SM6 (installation produced in France)
Transformers	Atmosphere, environment	cast resin transfo (avoids constraints)
LV switchboard	Atmosphere, IS	MLVS: Prisma + P Sub-distribution: Prisma +
Busbar trunking	Installed power to be supplied	analis KS
UPS units	Installed power to be supplied,back- up time	Galaxy PW
Power factor correction	Installed power, presence of harmonics	LV, standard, automatic (Average Q, ease of installation)

“2 substation” solution

Ditto apart from:
LV circuit: 2 remote MLVS connected via busbar trunking

Fig. D31: Detailed single-line diagram (2 substations)

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