269 / 356
D-21
Busbars
The maximum load current for a set of busbars is a function of the thermal
environment.
The type and the size of the conductors must be determined in view of carrying the
required currents taking into account the temperatures reached in the switchboard.
These conductors are subjected to additional heat rise caused by the flowing current
(joule effect) and the connected devices.
The temperatures reached by the conductors and the insulating materials, etc. must
not exceed the maximum temperatures for which the products were designed.
Merlin Gerin busbars and distribution blocks are sized to operate without any
particular constraints for the assemblies in Prisma Plus switchboards operating
under normal environmental conditions (standard switchboard configuration, 35 °C
outside the switchboard, etc.).
DD381459
To determine the
Linergy busbars
required, see the tables on page D-24
.
They can be used to determine:
the type of Linergy busbars, as a function of:
the current
the IP value
the ambient temperature around the switchboard.
Linergy
busbars:
I
y
1600 A.
Double Linergy
busbars:
1600 A
<
I
y
3200 A.
b
v
v
v
DD381460
To determine the required
flat busbars
, see the tables on page D-23 (horizontal
busbars) and on page D-25 (vertical busbars)
They can be used to determine:
the permissible current as a function of:
the size of the busbars
the number of bars
the ambient temperature around the switchboard
the IP value.
Flat copper busbars
5 mm thick: I
y
1600 A.
Flat copper busbars
10 mm thick: I
y
3200 A.
b
v
v
v
v
Connection of devices
u
630 and
busbar connections
To determine the
size of upstream and downstream connections
for devices, see
the tables starting on page D-27.
They can be used to determine:
the size of copper busbars
the maximum permissible current.
As a function of:
the type of circuit breaker
the IP value
the ambient temperature around the switchboard
the type of installation.
b
b
b
b
b
b
Designing Prisma Plus
power circuits
Presentation and approach
Additional informations
Designing electrical
characteristics