DCS lightning protection issues

You can ask the Allen-Bradley manufacturer to see how they handle it.

Some safety barriers have lightning protection functions. If you don’t have a safety barrier, you can install a lightning protection barrier in front of the card reader to address this issue; a lightning protection barrier can also be installed on the side of the instruments on-site to prevent them from being damaged by lightning strikes.

Lightning protection is a very important task. In system lightning protection, the focus is on protecting the power supply, which can be achieved using UPS units. It is advisable to install safety isolation barriers before the field instruments are connected to the system cards; it is even better to use units equipped with lightning arresters. According to available information, building lightning protection systems and lightning rods can only absorb 50% of the energy from lightning strikes, so important equipment installed within buildings still requires proper lightning protection measures.

No way, the control system wouldn’t lack lightning protection. Uninterruptible power supplies do have lightning protection features; when there are voltage abnormalities, they cut off the power supply and activate the UPS to provide power. If it’s not caused by the power supply, then the person in question can install a safety barrier to solve the problem

～～～～～～～～～～～～～～～～～～～ The lightning protection measures implemented on the instruments are primarily aimed at preventing induced lightning, that is, the additional currents and voltages that arise on the cables after a lightning strike. The method to prevent this is by using SPDs (surge protective devices), which are mainly used to protect the field instruments and the DCS. On the DCS side, cabinet-mounted SPDs are used, placed in front of the safety barrier cabinets. There is also an SPD to protect the DCS power supply. Important instruments on the field side also need to be equipped with SPDs; for example, pressure transmitters can use a screw-in SPD that is installed at an additional interface on the transmitter. Lightning protection is a fairly complex issue; there are many other aspects such as grounding, and simply installing an SPD isn’t enough to solve everything. Those in need can refer to www.mtlsurge.com, where there are some articles on lightning protection written by MTL Company. Moreover, the lightning protection standards for SH are also about to be released; I saw the draft a few days ago, but it’s not yet the official standard.

Zhejiang University’s ZHKong DCS engineering manual provides a detailed description of lightning protection; go and find one to read – it’s not complicated. Just do it according to the specifications.

Lightning protection is indeed a systematic endeavor; many aspects need to be taken into consideration. For new projects, considerations must start at the architectural level, including shielding and grounding, among other things!

Add surge protection isolation devices to separate the field instruments from the DCS.

I have always believed that surge currents are primarily a concern for electrical equipment, as such equipment is often capacitive or inductive; when it starts up, a large current surge occurs, which is why surge protection devices are necessary. For instruments, lightning protection mainly involves grounding, which is used to direct current into the grounding system ； The lightning protection for instrument control systems should also utilize the lightning protection system designed by electrical specialists, rather than one that is set up on one’s own. Please share your opinions.

There are various forms of lightning strikes, and I think that for our installation purposes, the simplest one is also the most practical. All that needs to be done is isolation, shielding, and grounding. An isolation transformer should be installed at the system’s power supply terminal; the cable trays and pipelines used for wiring must be properly shielded and grounded. The grounding system must be designed separately and must not be shared with the power supply’s grounding system. My previous company faced similar issues; after carrying out the above actions, failures caused by lightning strikes and surges were significantly reduced.

Isolation, shielding, surge protection, and lightning protection are systematic processes that cannot be explained in just a few sentences, haha

I have some materials here that you can take a look at; they might be helpful