Lightning-induced trip
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We are a chemical plant with high levels of continuous production. However, every year during the thunderstorm season, lightning strikes that cause power lines to trip pose a problem for our management and electricians; this not only disrupts production but also poses a threat to safety. We have removed the loss-of-voltage coils from the circuit breakers on the distribution lines, but we are still unable to prevent the contactors on individual motors from tripping due to loss of voltage. We considered adding a delay circuit to each important contactor, but were concerned about safety issues and lacked the necessary technical data. Could someone experienced help me here?
It’s been such a long time – why isn’t anyone answering?
Lightning and thunder are natural phenomena, and at present humans are still unable to prevent the disasters caused by lightning. The technical measures taken to protect power grids against lightning are only passive forms of protection. Every year, during the thunderstorm season, these phenomena cause huge economic losses to businesses and individuals. There is currently no effective solution to the problems you are facing; however, I advise against using so-called \"delayed circuit\" methods, as such approaches will only exacerbate the problem and cause greater damage to the power grid. I recommend that your company’s leadership pay attention to the knowledge on lightning prevention provided by China Electric Power Grid.
First, check the lightning protection system in your facility to see if there are measures in place to deal with direct lightning strikes and induced lightning. Secondly, the facilities must be reliable; lightning arresters need to be regularly checked, and the leakage current should not be too high. Ensuring that they shut down promptly after an incident can reduce the likelihood of being struck by lightning, so that at least within your facility, there will be no problems with tripping due to lightning strikes. This post was last edited by lihy on 2009-2-13 21:27.]
There are several problems after adding a delay circuit, some of which are fatal. 1. The contacts are prone to burning; in severe cases, they may burn and stick together ； 2. Poor control: Enterprises may experience explosions when facing this issue in production ； 3. It is easy to cause the main incoming power switch to trip. We have specific solutions for this problem, but the approach will depend on the actual conditions on site. Please send your specific requirements to the email addresses 1095421489@qq.com or LJJLWLY@163.com, and I will develop a solution tailored to your needs. What do you think?
As for tripping due to lightning strikes, it is sufficient to install a lightning surge relay in the control circuit; this approach is both safe and cost-effective. The specific model to be chosen should be determined by following the instructions provided for that lightning surge relay, based on the equipment that needs to be protected.
For the problem of tripping due to lightning strikes, you just need to press the surge relay. This allows the system to start up again when there is a lightning-induced trip, thereby reducing downtime in production
The company’s power distribution equipment should be equipped with lightning protection facilities to shorten the maintenance cycle of high-voltage power distribution devices. Prevent pollution flashover.
Are your lines overhead or cable? If it is an overhead line, does it have a lightning conductor? How is a lightning arrester installed? A common situation at the site is that when lightning is conducted to the ground by a lightning arrester, it causes the ground potential to rise; therefore, the lightning arrester should have its own separate grounding to prevent accidental activation of other equipment. But the current situation is that the design and construction of many projects in the country are not very standardized, which causes problems for users.
If a single motor is not properly grounded, could this be due to the leakage protection system? Is it possible that the building lacks lightning protection? Simply disabling the protection mechanism is useless; it will only lead to greater losses