CIPer
TM
MODEL 50 CONTROLLER
–
INSTALLATION AND COMMISSIONING INSTRUCTIONS
31-00233-02
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APPENDIX 1: Earth Grounding
CIPer Model 50 Systems and SELV
In order to avoid distribution of noise or earth ground potential differences over networks or other
connections, the CIPer Model 50 controller 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 Honeywell external (CRT series) or internal transformers comply with standard
EN60742.
Earth grounding is therefore not recommended.
CIPer Model 50 Systems and Standard EN60204-1
However, if compliance with EN60204-1 is required, note the following:
General Information
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.
In order to fulfill PELV (if earth grounding is prohibited), the use of an earth leakage monitor is also possible.
When is EN60204-1 applicable to CIPer Model 50 Systems?
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Safety against electrical impact
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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
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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
NOTE
We strongly recommend that each CPU be supplied with electricity from its own dedicated
transformer.
•
If system protective earth grounding is planned, use a cable as short as possible for grounding:
min. 1.5 mm² (16 AWG).
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For connection details, refer to the following examples.
Example 1:
The following explains how to connect and earth multiple CPUs (e.g., multiple CIPer Model 50 controllers,
Spyder, Stryker etc. or any combination thereof) earth-grounded as per EN60204-1.
