continuous.
98 Electrical installation
Note 1: Keep the shields continuous as close to the connection terminals as possible.
Secure the cables mechanically at the lead-through strain relief.
Note 2: If the outer surface of the shield is non-conductive:
• Cut the shield at the midpoint of the bare part. Be careful not to cut the conductors or
the
grounding wire (if present).
• Turn the shield inside out to expose its conductive surface.
• Cover the turned shield and the stripped cable with copper foil to keep the shielding
contin
uous.
Note for top entry of cables: When each cable has its own rubber grommet, sufficient IP
and EMC protection can be achieved. However, if very many control cables come to one
cabinet, plan the installation beforehand as follows:
1. Make a list of the cables coming to the cabinet.
2. Sort the cables going to the left into one group and the cables going to the
right into
ano
ther group to avoid unnecessary crossing of cables inside the cabinet.
3. Sort the cables in each group according to size.
4. Group the cables for each grommet as follows ensuring that each cable has a
proper
contact to th
e cushions on both sides.
Cable diameter in mm Max. number of cables per grommet
<
13 4
<
17 3
< 25 2
>
25 1
A Stripped cable
B Conductive surface of the shield exposed
C Stripped part covered with copper foil
1 Cable shield
2 Copper foil
3 Shielded twisted pair
4 Grounding wire
1
A B C
2 2
3
4
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