It is very common that during or after lightning strike or thunderstorm, control and instrumentation system devices experience problems, such as false alarms and trips or even total damage to certain parts. This article will briefly discuss the symptoms and possible causes harm of DCS and PLC disturbances during lightning strikes. —Omazaki Consultant is a consultant who provides troubleshooting services for your faulty control and instrumentation systems, such as malfunction, error, broken, damage or failure distributed control systems (DCS), programmable control systems (PLCs) or automatic control system caused by indirect lightning strike or improper grounding or earthing installations. If you experience sensitive electronic equipment such harm automation devices and DCS damage or failure due to lightning in steam thermal power plant (PLTU), PLTGU, petrochemical industries, and so on, contact us by email at cs@omazaki.co.id or by filling out the contact form the form in contact.
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Symptoms Harm of DCS Problems Caused by Lightning
Disruptions or problems typically only occur when lightning strikes the building or related instrumentation. Symptoms of DCS problems due to or caused by lightning include:
- False alarm
- False trip
- Damaged card or analog input module
- Sensor burnt out
- Damaged other sensitive electronic equipment
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Possible Causes of Faulty DCS
There are many possible causes of problems or damage to faulty DCS devices related to lightning strikes, including:
- Errors in the external lightning protection system
- Inappropriate selection of external LPS design between isolated system type or non-isolated
- Direct strike to the structure or building
- Nearby strike which produce large electromagnetic pulse (EMP)
- Bad in lightning current dissipation (bad grounding design or installation)
- Bad inspection and maintenance
- and other
- Errors in the internal lightning protection system
The internal lightning protection system is designed to safely conduct induced lightning currents or overvoltages to ground, thereby protecting equipment and systems from damage and ensuring their continued safe operation in the event of a lightning strike.
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- Surge protection devices (SPDs)
- Protective or electrical earthing (PE)
- Instrumentation earthing (IE)
- Incorrect separation distance
- Inappropriate separation distance of down conductor to surrounding mental
- Incorrect separation distance between lightning ground electrodes
- Errors in bonding installation
- Bonding is above ground
- Errors in instrumentation device installation
- Incorrect shield wire wiring resulting in a closed loop
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Recommendation
If a malfunction occurs in the instrumentation and control system during a thunderstorm, it is advisable to inspect all of the aspects mentioned above. A common practice in the field is to immediately attribute the problem to a specific cause, most often assuming that there is an issue with the earthing (grounding) system. Another common mistake is to jump to the conclusion that the system malfunctioned, or that a device was affected by lightning, simply because surge protection devices (SPDs) were not installed.
It is strongly recommended to follow an appropriate troubleshooting procedure or conduct a proper root cause analysis (RCA) until a truly accurate and effective solution is identified. This approach should be based on systematic analysis rather than trial and error, so that the same problem does not recur in the future.
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Contact Omazaki Consultant if you need consulting services for faulty harm of DCS or PLC problem or other sensitive electronic instrumentation and automation devices failure troubleshooting caused by lightning strike and/or bad grounding or earthing installation practices in your petrochemical industrial electricity or thermal power plant system.
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