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A S S E M B L Y O F T H E S W I T C H G E A R O N S I T E
5.10 Cable connection
5.10.1 Power cables
Power cables connection
•
The cables are routed from below through
the floor covering, which is divided at the cable
entry point. The cables go through rubber
reducer rings, which can be adapted to the
required cable diameter in a range from 35 to
54 mm (Fig. 62)
•
Cable sealing ends are mounted onto the
cable cores according to the manufacturer's
instructions. It is possible to use cable
sealing ends from different manufactures
(e.g. Pirelli, Raychem etc.), but it is necessary
to keep the length of the cable ends, including
cable sealing ends, which is given by the
distance of cable connecting bars from the
panel floor covering. These bars have different
versions, the difference being the number of
parallel cables and the values of the rated
and short-circuit currents
•
The bars are equipped with holes to
accommodate M16 screws. If M12 screws are
used for the cable connections, special
washers for these screws are also supplied. In
all cases, the earthing of the cable screens is
carried out on the strip-holding cable clamps.
The cable strip is connected to the earth
potential
•
The removable arrangement of voltage
transformers can also be placed in the cable
compartment. These can be fitted with
high-voltage fuses similar to those used in
the measuring panel. Three fixed-mounted
surge arresters can also be installed. However,
in both cases the number of parallel cables
must be reduced - see table below
—
Figure 59 a) Cable compartment
Connection of cables in typical panels:
Rated
Rated
Max.
voltage
current
number of
(kV)
(A)
parallel
cables per
phase
12
...1250
2
(1)(2)
(1) In the case where removable voltage transformers are on the
truck or surge arresters are used, the number of parallel cables
is reduced by one per phase.
(2) For an IF panel with cable bottom entry and depth of 1,650 mm,
up to 2 parallel cables per phase can be used.
Important notice
Typically, connections in the panel are made using
single-core plastic insulated cables. Special or
unusual cable connection cases (e.g. three-core
cables, cables with paper or special insulation
etc.) must be agreed between the customer and
manufacturer.
Mounting procedure for power cables:
•
The power cables must be first inserted, then
cut to length and stripped
•
The reducer rings must be adapted to the cable
diameter before being fitted onto the cable
•
Cable sealing ends must be prepared and
mounted on cable cores according to
manufacturer's instructions
•
The cable eyes must be connected to the
prepared connection bars with strain relief
•
The cables must be correctly earthed
•
Individual parts of the floor covering must be
mounted
•
The reducer rings must be moved down so that
nuts in the rings fit into the corresponding
recesses in the floor coverings. In this way the
cable passages are sealed
•
Cables must be fastened in the prepared cable
clamps (the maximum tightening torque
applicable to the clamp screws is 9 Nm)
39
Max.
Range
Range
cross
of
of
section
cable
reducer
of cables
clamp
ring
(mm
)
(mm)
(mm)
2
300
35-54
27-62
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