EMC
EMC (electromagnetic compatibility) describes the capability of electrical equipment to operate
without errors in a given electromagnetic environment, without being subject to external
influence and without influencing external devices in any way.
5.4.2
Possible effects of interference
Electromagnetic interferences can influence the electronic weighing system described here in
various ways:
● Electromagnetic fields having a direct influence on the system
● Interferences transported by communication cables
● Interferences having an effect via process cables
● Interferences entering the system via the power supply and/or protective ground
Interferences can impair the fault-free functioning of the electronic weighing system.
5.4.3
Coupling mechanisms
Depending on the propagation medium (conducted or non-conducted) and the distance
between the interference source and the device, interferences can enter the faulty device
through four different coupling mechanisms:
● Electrical coupling
● Capacitive coupling
● Inductive coupling
● Radiation coupling
5.4.4
Five basic rules for securing EMC
Observe these five basic rules to secure EMC.
Rule 1: Large area grounding contact
● When installing the devices, make sure that the surfaces of inactive metal parts are properly
bonded to chassis ground (see following sections).
● Bond all inactive metal parts to chassis ground, ensuring large area and low-impedance
contact (large cross-sections).
● When using screw connections on varnished or anodized metal parts, support contact with
special contact washers or remove the protective insulating finish on the points of contact.
Mounting
5.4 EMC-compliant setup
SIWAREX WP321
Operating Instructions, 08/2019, A5E33715669A-AD
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