4
Grounding point 3
5
Insulated mounting
6
Grounding point 2
7
Ground potential difference
8
Grounding point 1
9
Metal housing
ß
Shielded electrical cable
Even in the event of large differences in the ground potential, ground loops are effec‐
tively prevented. As a result, equalizing currents can no longer flow via the cable shields
and metal housing.
NOTICE
The voltage supply for the device and the connected peripheral devices must also guar‐
antee the required level of insulation.
Under certain circumstances, a tangible potential can develop between the insulated
metal housings and the local ground potential.
6.2
Wiring instructions
NOTE
Pre-assembled cables can be found online at:
•
NOTE
Pre-assembled cables with open cable end at one end:
Information about pin, signal and wire color assignments can be found in the appendix,
see "Signal assignment of cables with open cable end at one end", page 72
.
NOTICE
Faults during operation and device or system defects!
Incorrect wiring may result in operational faults and defects.
■
Follow the wiring notes precisely.
The protection class stated in the technical data is achieved only with screwed plug con‐
nectors or protective caps.
Design the circuits connected to the device as ES1 circuits or as SELV circuits (SELV =
safety extra low voltage). The voltage source has to meet the requirements of ES1 and
PS2 (EN62368-1) or SELV and LPS (EN 60950-1).
Protect the device with an external slow-blow fuse at the beginning of the supply cable.
Connect the connecting cables in a de-energized state. Switch on the supply voltage
only after complete installation or attachment of all connecting cables to the device
and control.
Perform all connection work only at ambient temperatures above 0 °C.
Connect the device only to the permissible supply voltage,
Wire cross-sections in the supply cable from the customer’s power system must be
selected and implemented in accordance with the applicable standards.
6
ELECTRICAL INSTALLATION
36
O P E R A T I N G I N S T R U C T I O N S | Lector621
8022502/15NT/2020-02-11 | SICK
Subject to change without notice