AC500 and AC500-eCo PLC devices are Class II/Class III devices and do not require a Protective Earth (PE) connection.
For proper EMC performance, all metal parts, DIN rails, mounting screws, and cable shield connection terminals are connected to a common ground and provide Functional Earth (FE). This is typically connected to a common reference potential, such as equipotential bonding rails.
Signal Grounds (SGND or GND) are used for signal reference and must not be connected to cable shields, FE or other signals unless otherwise specified in the specific device description.
General considerations
Electric and electronical devices have to work correctly on site. This is also valid when electromagnetic influences affect them in defined and/or expected strength. The devices themselves must not emit electro-magnetic noises.
Advant controller components have a very high noise immunity.
When the wiring and grounding instructions are met, an error-free operation is given.
High electro-magnetic noises of nearby mounted applications must be taken in consideration during the planning phase.
An EMC compatible earthing concept will also guarantee an error-free operation here.
In order to prevent operating malfunctions, it is recommended, that the operating personnel discharge themselves prior to touching communication connectors or perform other suitable measures to reduce effects of electrostatic discharges.
There are three important principles to be especially considered.
There are three important principles to be especially considered.
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Keep all connections as short as possible (in particular the grounding conductors).
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Use large conductor cross sections (in particular for the grounding conductors).
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Create low-impedance, i.e. good and large-sized contacts (in particular for the grounding conductors).
Pay attention to the following:
Pay attention to the following:
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Use vibration-resistant connections.
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Clean metallic contact areas.
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Use solid plug and screw-type connections.
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Use earth cable shields with clips on a well-grounded metallic surface.
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Do not use aluminium parts.
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Do not use sheath wires.
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Do not use toothed lock washers under screw connections.
Make a connection between the DIN rails and PE (Protective Earth). For this, use an grounding wire with a minimum conductor cross section of 10 mm².
The wire is connected to the DIN rail with an M6 screw.
A large-area contact of the DIN rail with the metallic mounting plate improves the EMC behavior significantly, as the disturbances can be discharged more effective.