Low-voltage fuses are a very important part of electrical circuits. Because the control panels have low-voltage components and are very critical in nature, due to their sensitivity and importance, fuses are required to protect them from any damage. As you are aware, every electrical device must comply with an international standard for use in the market. In the same way, low-voltage fuses are also related to an international standard. This standard is IEC-60269. It is a crucial standard to learn when dealing with low-voltage fuses. In this post, we will see why IEC-60269 is important.
What is IEC 60269?
As the name implies, IEC 60269 is an international standard that comes under the family of IEC (International Electrotechnical Commission). It deals with the standard construction, current limitations, operational parameters under various environmental factors, performance to trip in case of overcurrent, testing procedures for performance before using in the market, and safety and protection performance of the low-voltage fuses. These fuses are used in mostly LV or low voltage panels, which have a maximum voltage rating of 1000V AC or 1500V DC. As fuses are meant to protect the component in case of overcurrent or the current exceeding the rated fuse current limits, complying with this standard is necessary so that the overall design of the fuse is taken care of.
The standard is divided into five parts:
- Part 1 – General requirements
- Part 2-1, 2-2 – Supplementary requirements for fuses used by authorized persons
- Part 3 – Fuses for residential and smaller applications
- Part 4 – Fuses for protection of semiconductor devices
- Part 5 – Guidance for the application of fuses
So, if you see in short, the standard first says the requirements which apply to fuses and are common to all, the types of fuses covered in this standard according to their application, and a detailed technical guidance on how to use the fuses, finally, after considering the first four parts. It thus covers all the basics from the start of identification to the end of usage. Refer to the image below on how a fuse is symbolised. Basically, before passing the current from an incomer to the load, a fuse is connected in between that senses the amount of current flow. As soon as the current exceeds its maximum current rating, it blows itself and opens the circuit. This prevents the load from getting damaged due to overcurrent or short circuit.
Let us now understand the main highlights of the parts discussed:
- Defines what amount of current and voltage that must be rated in the fuse for protection. Accordingly, what markings should be done on the fuse cover for information.
- Defines how the fuse must be tested for short circuit, temperature rise, or overcurrent, which will then indicate that the fuse has been tested fine to perform under real-time conditions.
- Covers the types of fuses used in low voltage applications, like for industrial boards and panels, domestic homes, or other small business types, and semiconductor applications (the most sensitive of all the types of fuses).
- Discuss in technical details regarding the types of loads the fuse will protect, under what environment the fuse will perform, and thus help in the final selection of the fuse.
IEC 60269 in Electrical Applications
Now that we have understood the meaning of the IEC-60269 standard, let us dive into the importance of this standard for the usage of low-voltage fuses:
- As the standard means that the fuses must be designed according to it only, go to any part of the world, and if you find a faulty fuse, just replace it with a fuse that complies with the same standard. Your work will be done. So, this standard ensures reliability and trust that the fuses are manufactured considering the same standard in mind, and you can replace them anytime, without worrying about the aftermath.
- As fuses are designed to blow themselves in the case of a fault, you will be assured that in the event of any short circuit, overcurrent, or temperature rise, the fuse will perform as it has been tested in all conditions according to the standard.
- If you want to comply with a low-voltage fuse with this standard, then this standard will apply a class to it based on the application, like a general circuit, a motor circuit, a photovoltaic circuit (solar power), or a semiconductor circuit. This helps to easily identify and use the fuse according to its application.
- The fuse will have the same physical dimensions if the standard is followed, making it easy for replacement and maintenance.
Due to the above-mentioned points, a low-voltage fuse will work properly and safely in any specified environment and protect the load from any damage. In this way, we saw why IEC-60269 is important for electrical applications.
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