Chapter A General rules of electrical installation design

D20
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D - MV & LV architecture selection guide
7 Choice of architecture details
7.2 Centralized or distributed layout
In centralized layout, current consumers are connected to the power sources
by a star-connection. Cables are suitable for centralized layout, with point to point
links between the MLVS and current consumers or sub-distribution boards (radial
distribution, star- distribution) (Fig. D13):
Fig. D13: Example of centralized layout with point to point links
In decentralized layout, current consumers are connected to sources via a busway.
Busbar trunking systems are well suited to decentralized layout, to supply many
loads that are spread out, making it easy to change, move or add connections
(Fig D14):
Fig. D14 : Example of decentralized layout, with busbar trunking links
Factors in favour of centralized layout (see summary table in Fig. D15):
b Installation flexibility: no,
b Load distribution: localized loads (high unit power loads).
Factors in favor of decentralized layout:
b Installation flexibility: "Implementation" flexibility (moving of workstations, etc…),
b Load distribution: uniform distribution of low unit power loads
Schneider Electric - Electrical installation guide 2008