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D-20
The Prisma Plus system takes into account the
installation and connection conditions of
Schneider Electric devices.
The entire installation complies with standard IEC
60439-1. The result is a type tested switchboard.
In the following pages you will find a number of examples, validated for Prisma Plus
switchboards, intended to assist in determining the busbars as well as the upstream
and downstream connections for the installation.
The examples assume that the devices have already been selected.
A complete process involves a number of steps before making final choices
(transformer, conductors, protection, etc.).
Schneider Electric offers a number of tools to assist in designing a complete
installation (technical guides, software).
PD390311
Busbar sizing
The factors that must be taken into account in determining the size of busbars
include:
the diversity factor.
Not all the loads supplied by a set of busbars are used at full rated load or at the same
time. The diversity factor is the means to determine the maximum load current used
to size the busbars.
Standard IEC 60439-1 §4.7 specifies the table below.
b
Number of circuits
Diversity factor
2 and 3
0.9
4 and 5
0.8
6 to 9
0.7
10 and more
0.6
the degree of protection IP
the ambient temperature around the switchboard.
b
b
Designing Prisma Plus
power circuits
Presentation and approach
Additional informations
Designing electrical
characteristics