Can bare disc varistors be connected in parallel?

Can bare disc varistors be connected in parallel? Well, that's a question I get asked a lot as a supplier of bare disc varistors. In this blog post, I'm gonna dive deep into this topic, share some insights, and give you the lowdown on whether it's a good idea or not.

First off, let's talk about what bare disc varistors are. These are metal oxide varistors (MOVs) in their most basic form, without any additional packaging or protection. They're widely used in various applications for surge protection, thanks to their ability to quickly change their resistance in response to voltage spikes.

Now, the idea of connecting bare disc varistors in parallel might seem like a good way to increase the current - handling capacity or improve the overall performance of the surge - protection system. And in some cases, it can be. When you connect varistors in parallel, the total current - carrying capacity theoretically increases because the current can be divided among the individual varistors.

Let's say you have a single bare disc varistor that can handle a certain amount of current. If you connect two or more of these in parallel, they can collectively handle more current. This can be really useful in high - energy surge situations where a single varistor might not be able to handle the load.

However, there are some challenges and considerations when it comes to parallel - connecting bare disc varistors. One of the main issues is the matching of the varistors. Each varistor has its own electrical characteristics, such as breakdown voltage and clamping voltage. If these characteristics aren't closely matched among the varistors in parallel, one varistor might start conducting current before the others. This can lead to an uneven distribution of current, where one varistor takes on most of the load and could potentially fail prematurely.

For example, if you have two varistors with slightly different breakdown voltages, the one with the lower breakdown voltage will start conducting first. This means it will carry more current than the other varistor, which can cause overheating and failure. To minimize this risk, it's crucial to select varistors with very similar electrical characteristics.

Another consideration is the thermal management. When varistors are connected in parallel, they generate heat during operation. If the heat isn't dissipated properly, it can cause the varistors to overheat and degrade their performance. This is especially important for bare disc varistors, as they don't have the additional insulation or heat - dissipation features that some packaged varistors might have.

To address these issues, proper testing and selection of varistors are essential. Before connecting varistors in parallel, it's a good idea to test each varistor individually to ensure their electrical characteristics are within an acceptable range. Additionally, implementing a good thermal management system, such as using heat sinks or proper ventilation, can help keep the varistors at a safe operating temperature.

Now, let's take a look at some of the products we offer as a bare disc varistors supplier. We have the 34S Metal Oxide Varistor, which is a high - quality varistor suitable for a wide range of applications. It has excellent surge - handling capabilities and can be used in both single - varistor and parallel - connected configurations.

Our MOV DC is another great option. It's designed specifically for DC applications and offers reliable surge protection. Whether you're using it alone or in parallel with other varistors, it can provide effective protection against voltage spikes.

And if you're looking for a varistor for a surge protection device (SPD), our MOV Varistor For Spd is a top - choice. It's engineered to meet the demanding requirements of SPDs and can be used in parallel to enhance the overall performance of the SPD.

In conclusion, connecting bare disc varistors in parallel can be a viable solution for increasing current - handling capacity and improving surge - protection performance. However, it requires careful consideration of the varistors' electrical characteristics, proper matching, and effective thermal management. If you're unsure about how to proceed or which varistors are best for your application, don't hesitate to reach out to us. We're here to help you make the right decisions and provide you with the best products for your needs. Whether you're a small - scale electronics manufacturer or a large - scale industrial operation, we can offer you the support and expertise you need.

If you're interested in purchasing our bare disc varistors or have any questions about parallel - connecting them, please contact us. We'd love to have a chat with you and discuss your specific requirements. We can work together to find the best solution for your surge - protection needs.

References

• IEEE Standards for Surge Protection Devices
• Application Notes from Varistor Manufacturers