By Product Manager Alex Rodriguez
Surge events are inevitable, but they don’t need to be a headache anymore with new surge protection products from American Innovations.
Surge and lightning are prevalent in the United States and can be disastrous to cathodic protection (CP) systems and the remote monitors (RMUs) attached to them. According to the Vaisala 2020 annual lightning report, there were over 170 million lightning events recorded in 2020, with the majority occurring in the southern and eastern parts of the country.
The extreme nature of surge and lightning events requires extra consideration when installing remote monitors on CP systems to maximize their resiliency. We have found that surge and lightning events can be managed, and equipment will remain operational with a combination of improved grounding techniques, the addition of surge protection devices, and surge-hardened RMUs. A robust surge protection architecture is comprised of several layers of protection. Let’s look at how you can maximize your surge resiliency by optimizing the electrical grounding in the system, adding surge protection devices, and using surge-hardened RMUs.
How much is enough? What matters when evaluating your CP system’s grounding.
Grounding is an extremely important aspect of electrical system design and should not be overlooked. Its sole purpose is to divert surges in electricity away from electronic devices and into the earth. Rectifiers and RMUs each have their own grounding systems and it is important to understand how they interact with one another to ensure optimal grounding practices are followed. Here are a few things to consider when evaluating the grounding of your CP system
1) Ensure the ground wire is intact from the rectifier to earth. This wire can degrade over time when exposed to the elements, so it is important to ensure the core of the grounding system is in good condition. Similarly, make sure the ground rod is intact and making good contact with the earth.
2) Ensure all ground connections are connected to a single point in the rectifier to prevent ground loops. Ground loops can create different electrical potentials within a circuit that can reduce the efficacy of the grounding system which protect electronic devices.
3) Minimize length and remove coils or bends to connections leading to ground. The less resistance electricity needs to travel through the more effective the grounding system will be.
4) VERY IMPORTANT: When adding an RMU to an existing electrical grounding system, like the one on a rectifier, the goal is to keep those two systems on the same voltage potential to minimize the dangers of surge. If the RMU is contacting a rectifier when mounted, it is not advised to connect the ground cable of the RMU to the rectifier. However, if the RMU is mounted on a wooden pole, it would be advantageous to wire the RMUs ground to the single point in the rectifier where all other ground connections are attached.
Surge protection devices, like high-energy surge arresters (HESAs) and fuses, lessen the damaging effects of surge on electrical devices. High energy surge arresters reduce the amount of voltage experienced on an electrical circuit by diverting excess energy to ground once a voltage crosses a certain threshold. The threshold which triggers the surge arrester to start working varies from one model of surge arrester to another. A surge arrester built into a rectifier may be suitable to protect the rectifier’s circuits but may not provide any protection to an RMU. It is important to ensure you are using the appropriately sized surge arrester when used with a remote monitor. Because surge events can occur on either the AC or DC side of the circuit, it is important to use a surge arrester on each side.
No surge arrester on the market will protect against 100% of surge events because some can be of very high magnitude. In cases where surge is too high for a surge arrester to handle, the SurgeFuse is a great, low-cost device to ensure the RMU does not get damaged. Installing a SurgeFuse takes just seconds and goes between the output of your rectifier and the input of the RMU. A large surge event that exceeds the capabilities of the surge arrester will cause the SurgeFuse to sever the electrical connection to the RMU so it does not take damaging energy.
The last level of protection for enhanced resiliency
The last level of protection is on the RMU itself. The surge tolerance capabilities of the S-series RMUs have been increased to make it more robust against the kind of surge events RMUs experience. This was accomplished by redesigning the RMU’s main board to use more resilient components and using materials that limit arcing on the board. The remote monitor was tested using equipment to simulate voltage levels produced by lightning strikes and after hundreds of tests the RMUs remained operational.
Although the remote monitors are robust against the majority of surge events, the addition of optimal grounding, and surge protection devices further enhance the resiliency against surge and leads to the ultimate level of protection, less downtime, and cost savings.
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