SICK TiM361S

6 Commissioning and configuration
6.1 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:
■
Mounting the devices on conductive metal surfaces
■
Correctly grounding the devices and metal surfaces in the system
■
If necessary: low-impedance and current-carrying equipotential bonding between
areas with different ground potentials
If these conditions are not fulfilled, equipotential bonding currents can flow along the
cable shielding between the devices due to differing ground potentials and cause the
hazards specified. This is, for example, possible in cases where there are devices within
a widely distributed system covering several buildings.
Remedial measures
The most common solution to prevent equipotential bonding currents on cable shields
is to ensure low-impedance and current-carrying equipotential bonding. If this equipo‐
tential bonding is not possible, the following solution approaches serve as a suggestion.
NOTICE
We expressly advise against opening up the cable shields. This would mean that the
EMC limit values can no longer be complied with and that the safe operation of the
device data interfaces can no longer be guaranteed.
Measures for widely distributed system installations
COMMISSIONING AND CONFIGURATION
6
8022483/1LM2/2024-03-27 | SICK O P E R A T I N G I N S T R U C T I O N S | TiM361S
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Subject to change without notice