SG2 EXTENDED
Instruction Manual
28
4.2. Earth
connection
SG2 safety light curtain units are preset for easy ground connection. A special compartment,
positioned onto caps and marked with the special symbol shown in Figure 22, allows connection with
ground cable by means of an additional screw coming with the equipment.
Fig. 22
Ground connection configuration is the most common and guarantees the best immunity against
electromagnetic disturbances. SG2-B can function even without ground connection.
This condition has to be carefully evaluated according to the EMC disturbance immunity and
necessary insulation class considering the plant or entire system where the light curtain is installed.
The ground connection of the two units is not necessary for Class III, while the use of a duly-
insulated low-voltage feeder type SELV or PELV is compulsory. In this case, we recommend
covering the earth symbol present on the caps of the two units with a blank sticker.
The ground connection of the two units is compulsory for Class I, while the use of a duly-insulated
feeder type SELV or PELV is not compulsory but anyway recommended.
The following table is a summary of SG2-E electrical protections.
Electrical protections
Class I
Class III
Ground Connection
Compulsory
Not necessary
Ground connection symbol
Compulsory
Not necessary
Power supply by generators
SELV / PELV
Recommended Compulsory
