Appendix 1: System Protective Earth Grounding
LION
System
EN1Z-0921GE51 R0709
82
Appendix 1: System Protective Earth Grounding
LION Systems and SELV
In order to avoid distribution of noise or earth ground
potential differences over networks or other connections, the
CLLIONLC01 is designed to be in compliance with SELV
(Safety Extra-Low Voltage).
Furthermore, SELV offers the greatest possible safety
against electrical impact.
To support SELV, all CentraLine external (CRT series) or
internal transformers comply with standard EN60742.
Earth grounding is therefore not recommended.
LION Systems and Standard EN60204-1
However, if compliance with EN60204-1 is required, note
the following:
General Information about EN60204-1
EN60204-1 defines electrical safety for a complete
application/machine including controllers, sensors, actuators
and any connected/controlled electrical device.
EN60204-1 requires controllers to be powered by PELV
(Protective Extra-Low Voltage) and earth grounding of the
secondary side of the used transformers or earth grounding
of the system ground.
Earth grounding is prescribed to prevent unexpected start-
up of connected rotating/moving machines due to an
insulation fault and double earth grounding somewhere in
the plant.
The use of an earth leakage monitor is also possible to fulfill
PELV if earth grounding is prohibited.
When is EN60204-1 Applicable to LION Systems?
•
Safety against electrical impact
EN60204-1 is not mandatory; this is because electrical
safety is provided by the use of SELV and transformers
according to standard EN60742.
•
Safety against unexpected start-up of
rotating/moving machines
– If the application/plant does not contain machines that
can be harmful to the operator due to an unexpected
start-up, the standard EN60204-1 is not applicable.
If such machines are encountered, then EN60204-1 must be
followed. Grounding is required.
Earth Grounding of EN60204-1 Applicable
Systems
►
If system protective earth grounding is planned, use a
cable as short as possible for grounding:
min. 1.5 mm² (16 AWG).
►
For connection details refer to the following examples.
Example 1
Connecting a single transformer with multiple CLLIONLC01
Controllers earth-grounded as per EN60204-1
►
Connect earth ground to terminal 2 of the CLLIONLC01
Controllers
CLIOP/
CLIOL
CLIOP/
CLIOL
CLIOP/
CLIOL
CLIOP/
CLIOL
CLIOP/
CLIOL
CLIOP/
CLIOL
24 V
~
24 V0
CLLIONLC01
24
V
~
1
2
24
V
~0
CLLIONLC01
24
V
~
1
2
24
V
~0
LINE
NOISE-FREE EARTH GROUND
(ONLY ONE PER SYSTEM)
Fig. 110 Connecting and earth grounding multiple
CLLIONLC01 Controllers (single transformer)