6.1.1
Data cables
Important information
NOTE
Layout of data cables
■
Use screened data cables with twisted-pair wires.
■
Implement the screening design correctly and completely.
■
To avoid interference, always use EMC-compliant cables and layouts. This applies,
for example, to cables for switched-mode power supplies, motors, clocked drives,
and contactors.
■
Do not lay cables over long distances in parallel with power supply cables and
motor cables in cable channels.
Length of cable and data transmission rate
The maximum length of cable between device and host computer depends on the
interface type and the data transmission rate.
Further topics
•
For information on data transmission rates and lengths of cable:
6.2
Prerequisites for safe operation of the device
WARNING
Risk of injury and damage caused by electrical current!
As a result of equipotential bonding currents between the device and other grounded
devices in the system, faulty grounding of the device can give rise to the following
dangers and faults:
•
Dangerous voltages are applied to the metal housings.
•
Devices will behave incorrectly or be destroyed.
•
Cable shielding will be damaged by overheating and cause cable fires.
Remedial measures
•
Only skilled electricians should be permitted to carry out work on the electrical
system.
•
If the cable insulation is damaged, disconnect the voltage supply immediately and
have the damage repaired.
•
Ensure that the ground potential is the same at all grounding points.
•
Where local conditions do not meet the requirements for a safe earthing method,
take appropriate measures. For example, ensure low-impedance and current-carry‐
ing equipotential bonding.
The device is connected to the peripheral devices (any local trigger sensor(s), system
controller) via shielded cables. The cable shield – for the data cable, for example –
rests against the metal housing of the device.
The device can be grounded through the cable shield or through a blind tapped hole in
the housing, for example.
If the peripheral devices have metal housings and the cable shields are also in contact
with their housings, it is assumed that all devices involved in the installation have the
same ground potential
.
This is achieved by complying with the following conditions:
ELECTRICAL INSTALLATION
6
8024289/1E1C/2022-09-09 | SICK
O P E R A T I N G I N S T R U C T I O N S | GLS621
25
Subject to change without notice
