7.3 Installing Signal Lines and Signal Cables
Line Routing
The following measures are recommend:
●
Route signal and control lines separately from frequency converter power ca-
bles , motor power cables and brake chopper power cables with a minimum
distance of d
min.
= 100 mm or with a grounded separating sheet. The optimum
way is to route them in separate cable ducts. If possible, lead signal lines into
the control cabinet at one point only.
●
If signal lines are crossing power cables, route them in an angle of 90° in or-
der to avoid interference injection.
●
Ground spare cables, that are not used and have been connected, at least at
both ends so that they do not have any antenna effect.
●
Avoid unnecessary line lengths.
●
Run cables as close as possible to grounded metal surfaces (reference poten-
tial). The ideal solution are closed, grounded cable ducts or metal pipes
which, however, is only obligatory for high requirements (sensitive instrument
leads).
●
Avoid suspended lines or lines routed along synthetic carries, because they
are functioning like reception antennas (noise immunity) and like transmitting
antennas (emission of interference). Exceptional cases are flexible cable
tracks over short distances of a maximum of 5 m.
Shielding
Connect the cable shield immediately at the devices in the shortest and most di-
rect possible way and over the largest possible surface area.
Connect the shield of analog signal lines at one end over a large surface area,
normally in the control cabinet at the analog device. Make sure the connection
to ground/housing is short and over a large surface area.
Connect the shield of digital signal lines at both ends over a large surface area
and in short form. In the case of potential differences between beginning and
end of the line, run an additional bonding conductor in parallel. This prevents
compensating current from flowing via the shield. The guide value for the cross
section is 10 mm
2
.
You absolutely have to equip separate connections with connectors with groun-
ded metal housing.
In the case of non-shielded lines belongs to the same circuit, twist feeder and
return cable.
Brake Chopper
Bosch Rexroth AG
Electromagnetic Compatibility (EMC)
DOK-RCON03-EFC*BRAKE**-IT01-EN-P
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