Some circuits need to carry on higher load circuits, and this might call for multiple fuse links in parallel as to evenly distribute the electrical load. To do this, you must have identical rated currents for all fuse links, minimal resistance variation between fuses, and proper synchronization of load splitting. And of course, safety is an absolute must. When a parallel fuse is set up with a lot of planning and care, it can allow for a higher current capacity while maintaining system protection.
Let’s break down how to calculate the required rating for using our SIBA HV fuses in parallel applications, along with other key considerations.
How to Calculate the Required Rating for Parallel Medium Voltage Fuses
When fuses are connected in parallel, the current rating total is actually greater than the sum of the rated currents of the individual fuses. When considering safety and reliability, this value needs to be adjusted.
Key Formula:
Total Current Rating= (Fuse 1 rated current+Fuse 2 rated current+…+Fuse N rated current) ×Safety Factor
Example Calculation:
If you have two 50A MV fuses in parallel and apply a safety factor of 1.2*:
(50A+50A) ×1.2=120A
This ensures the system operates within safe limits while accounting for potential variations in load and current sharing.
Key Considerations for Parallel Fuse Applications
1. Fuse Type and Compatibility
- Always use identical fuses that have the same voltage rating to ensure an even current distribution.
- These parallel fuses must be designed for high-voltage applications to effectively handle short-circuits.
2. Current Sharing & Load Balancing
- In an ideal situation, a current should divide equally between fuses in a parallel setup. However, minor variations in manufacturing tolerances can lead to an uneven distribution.
- In order to minimize variations in internal resistance, fuses must be used from the same production batch.
3. Safety Factor
- To account for potential load fluctuations, apply a safety factor (typically 1.1 to 1.25). This also provides protection from other various conditions.
4. Manufacturer Guidelines
- Make sure you refer to SIBA’s technical datasheets to gain information on specific recommendations for parallel fuse applications, such as the best way to install them and rated current values.
Why Choose SIBA HV Fuses?
SIBA HV fuses thrive in medium voltage applications, and have many features and advantages:
✅ Reliable Sealing to protect against humidity, dust, and corrosion
✅ Long service life with limited age degradation
✅ Low power losses to ensure energy efficiency and protection from overheating
✅ High breaking capacity that prevents damage by using fast current limitation
✅ Low switching voltage to enhance overall system stability
✅ Decades of proven real-world reliability
You can also use SIBA HV Fuses for a number of various applications, including:
- Distribution transformers
- Motor circuits
- Capacitor banks
- Voltage transformers
- Cable feeders
SIBA’s Fast Current Limitation Advantages
While SIBA’s HV fuses offer a myriad of features, benefits, and applications, one aspect that shines the most is its ability to quickly limit short-circuit currents, protecting your equipment and switchgear from thermal and dynamic damage. This is essential for high-current applications where you need a fast response to avoid any catastrophic failures.
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Using parallel MV fuses lets you have high system reliability while also allowing for increased current capacity. If you follow these essential calculation methods, consider load balancing factors, and use SIBA HV fuses, you can guarantee optimal performance and protection for your project.
Have questions or need assistance selecting the right fuses for your system? Contact us today! If you would like to check out a variety of products that we handle that will suit your needs, please visit our website and submit a quote at https://hill-tech.com/, contact us at 847-255-4400, fax us at (847) 255-0192, or email us at sales@hilltech.com. And be sure to look at our social media pages, linked below!
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