Introduction
The precautionary measures related to earthing incorporated in the PLC, VFD, and instrumentation system must be taken cautiously because of the sensitivity involved in control, signaling, and communication circuitry methods. Essentially poor or improper earthing in industrial establishments may introduce unwanted electrical noise, false alarms, or malfunctioning equipment.
The surges and transients introduced by lightning can also travel through electrical power as well as control and communication lines. Consequently, equipment may be damaged, operations may cease unexpectedly, safety may be affected, operational disruptions may occur, etc. Thus, the installation of the proper earthing design contributes to the elimination of unnecessary voltage differences and maintaining the stability of the functioning of automation and instrumentation devices.
About LPES International
LPES International is an engineering company that concentrates on electrical protection by combining Lightning Protection, Power Protection, Earthing Protection and Surge Protection in a unified engineering manner. LPES has many capabilities for industrial, commercial and infrastructure facilities which range from lightning risk assessment to engineering design, protection layouts, technical studies, system coordination, inspection, testing and verification.
The main objective is to implement a coordinated protective system that takes into account not just power equipment but also automation systems, communication circuits and sensitive electronic devices
Common Mistakes to Avoid
PLC, VFDs and instrumentation devices must not be connected to points of earth that are not synchronized. Any cables with sensitive signals must not be laid too close to VFD output or cables from other mains supply lines where high levels of interference may occur. If cables are not terminated properly, electrical noise may appear in signals due to ungrounded cable shields. Surge protection systems must be installed only for the incoming power sources while any communication and signal wires stay unprotected. Do not skip such important tests as continuity, bond and earth tests after installation and commissioning of the system.
Key Lightning Protection Solutions
Earthing and Grounding Systems
Provided that the electrical systems, PLC control systems, VFD drive enclosures and instrumentation layouts that comprise the coordinated earthing network are connected, there will always be an analog referential electrical ground at any point in the electrical systems.
Equipotential Bonding
The process of bond legislation of metal control systems, cable channels, equipment bodies and conductive surfaces will reduce the difference in potential between all points, providing protection to sensitive equipment.
Surge Protection Devices
The implementation of effective surge protection devices for power circuit, data transfer, control and operation systems will help to limit the size of the transient overvoltage occurring at the input to the circuits governing inputs of PLCs or VFD drive systems.
System of external lightning protection
In case of necessity, the system of protection from lightning must be equipped with a system of air grounding, a system of lightning current taking-off and a system of grounding to provide the deviation of lightning currents from the electrical equipment into the ground.
Lightning Risk Assessment and Engineering Design
The coordinated procedure of risk assessment enables to determine exposure level, surges taking pathways, earthing needs and protection zones with regards to automation and control systems.
Benefits of Professional Lightning Protection Systems
Well-designed lightning protection systems not only prevent equipment damage and electrical disturbances but also improve safety. Lightning protection systems can safeguard PLC processors, VFD electronic controls, sensors and transmitters and other sensitive instruments. Proper earthing, bonding and surge protection can further reduce the risk of system failures and enable long-term efficiency of plants.
Conclusion
Effective earthing for PLC, VFD and instrumentation systems should be designed as part of the complete electrical and lightning protection network. Earthing, bonding, cable routing and surge protection must work together to protect sensitive automation systems.
LPES International supports businesses with lightning risk assessment, surge protection, earthing systems, grounding systems and coordinated protection design. Connect with LPES International for engineered electrical safety solutions suited to your facility and automation infrastructure.
