6
Electrical installation
6.1
Safety
6.1.1
Prerequisites for safe operation
WARNING
Risk of injury and damage caused by electrical current!
As a result of possible equipotential bonding currents between the device and other
earthing devices in the system, faulty earthing of the device can give rise to the
following dangers and faults:
•
Metal housings are vulnerable to dangerous electrical voltage.
•
Devices will behave incorrectly or be destroyed.
•
Cables will be damaged by overheating or 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, switch off the voltage supply immediately.
Arrange for repair.
•
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 (voltage supply, any local trigger
sensor(s) and system controller) via cables.
The device can be grounded e.g. via a blind tapped hole of the housing.
If the peripheral devices also have metal 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
cables between the devices due to differing ground potentials. The currents may lead
to the above-mentioned hazards. This is, for example, possible in cases where there are
devices within a widely distributed system covering several buildings.
ELECTRICAL INSTALLATION
6
8026854//2021-09-01 | SICK
O P E R A T I N G I N S T R U C T I O N S | RFU61x IO-Link
29
Subject to change without notice
