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GENERAL INSTRUCTIONS FOR PREFORMA PF-4 / 5
ASSEMBLY AND USE OF PREFABRICATED PRIVATE
SUBSTATIONS (LV METERING)
IG-138-FR
version 02
02.10.2007
Page 9 of 28
1.3.2. MV switchgear
The PREFORMA-PF substations take MV boards of
type HN64-S52/IEC 62271-200
. The
assembly must be done in accordance with the manufacturer's instructions. The number of
cubicles that can be incorporated depends on their dimensions.
On the average basis of 375 mm per functional unit, the PREFORMA-PF-4 / 5 can
incorporate 4 and 5 functional units respectively
[
1
]
.
Within the limit fixed, it is possible to make an Ormazabal extension in the PREFORMA-PF
substation.
At least, the board will be made up of one switch input (distributor input) and one combined
fuse protection cubicle (protection of the transformer). Substation located at antenna.
Furthermore, the feedline break and double bypass electrical diagrams can be produced.
The protection bypass is fitted with at least one tripping coil on switch opening and locking
keys positioned on the earthing disconnector in order to ensure the safety of switching
operations during operation.
1.3.3. MV Connection
The connection must be made according to the instructions of the functional units, in
synthetic-insulated tri-polar cable according to standards NF C33-223 or NF C33-226 of
cross-section less than or equal to 240 mm
2
. Connections to the MV equipment depend on
the type of cubicle. They are to be executed with 400 A type separable elbow terminals of
type 400 A compliant with the NF C33-051 standard.
The MV equipment / transformer connection is made by synthetic-insulated unipolar cables
compliant with standard NFC33-223 or NFC33-226 of 50 mm
2
aluminium fitted with
separable connectors in compliance with the NF C33-051 standard of type 250 A. The
connection is to be fixed with the fixtures provided for this purpose and placed on the wall.
1.3.4. MV Cable Curvature Radii
The layout of the equipment in the substation allows adherence to the minimum curvature
radii provided by regulations.
MV Cable
Single pole
150 to 240 mm
2
MV Cable
Twisted
150 mm
2
MV Cable
Twisted
240 mm
2
NFC33-223
NFC33-226
600 mm
800 mm
900 mm
The "knock-out" holes for cable entry are placed on an inclined plane, which makes it
possible to limit the height of the pit while allowing for the curvature radius of the cables.
[1]
For other layouts, consult Ormazabal's Technical – Sales Department.
N.B. :
Use a stone chisel to knock out the entry holes.
