An electronic fuse is a safety device used to protect electrical circuits from damage caused by overcurrent. A fuse is placed in series with a circuit and is used to “blow” or open the circuit when the current flowing through it exceeds a certain value.
A fuse holder is a device used to hold or install an electronic fuse. Fuse holders come in a variety of shapes and sizes for both low and high-voltage applications.
In this article, we’ll take a closer look at fuse holders and discuss some of the things you need to know about them.
What is a fuse holder?
Fuse holders are an essential part of circuit integration for fuses that cannot be dropped in directly. They provide a secure connection and robust current path, which protects against voltage bleed. Additionally, fuse holders make it easy to replace the fuse when it’s been damaged by over-current.
How does a fuse holder work?
Fuse holders (or fuse accessories) are devices that facilitate efficient transmission of power through the fuse. These components often include added features designed to provide OEMs and end users with extra functionality.
At a high level, here are some common features of fuse accessories:
- Terminals are responsible for conveying electrical current into and out of fuse accessories. They provide an efficient connection to the circuit, allowing it to receive and return electrical current.
- Contacts are components that are responsible for connecting with the fuse, allowing current to flow between the fuse and other system components. Commonly contacts exist in the form of clips or eyelets.
- The supplemental components associated with a fuse holder are dependent upon the type of product it is. As such, they may vary across different types of fuse holders.
The different types of fuse holders
When selecting fuse accessories, it’s essential to familiarize yourself with the varying types of holders. BITUO offers four categories: Printed Circuit Board (PCB) Fuse Clips, Printed Circuit Board Fuse Holders, Panel Mount Fuse Holders, and Inline Fuse Holders. Understanding this range of products will help you choose the right one for your needs.
PCB Fuse Clips
PCB fuse clips offer cost-efficient solutions for a wide range of applications, with the lowest buying price but typically having fewer features than other available options. To ensure that they function optimally, these clips must be insulated or isolated from the exterior environment.
PCB Fuse Holders
Cost efficiency is a hallmark of low-end products, which tend to have the lowest acquisition cost but fewer features. These products typically require insulation and isolation from their environment but can be used in a wide variety of applications.
Panel Mount Fuse Holders
Mounted through an enclosure or on a backplane of an enclosure, they are generally wire-in, wire-out/line, and load, and can protect people from electrical hazards when installed properly.
Inline Fuse Holders
The wire-in, wire-out/line, and load fuse holders are self-contained wire harnesses that provide a great deal of flexibility. These holders can be designed to allow for easy replacement of fuses or limit access, depending on what is most suitable for the designer’s objectives and the locations where they are placed.
Fuse holder considerations
When selecting a fused accessory to integrate into an electrical circuit, here are a couple of items to keep in mind:
Installation Type
For electronic circuits, there are two installation types – printed circuit board applications and wire-in, wire-out applications. The fuse holders available and possible features will differ greatly depending on the application.
Fuses Accepted
The most common electronic fuses that require accessories are cylindrical; therefore, fuse accessories typically accept different cylindrical fuses based on the diameter of the fuse (most are 1/4” (6.3 mm) and 5 mm fuses), i.e. BITUO’s fuse holder shown.
Accessibility/replaceability
During normal operation and after an over-current event is properly managed by the opened fuse, this brings two points of consideration: fuse accessibility and how easy it is to replace the fuse to regain operation. Fuse accessories can provide an easy way to change a fuse, as well as protect people against electrical hazards interacting with the equipment in which it is installed.
There are a couple of different ways of defining this protection, sometimes referred to as Shock Safety, namely in IEC60127-6 or UL4248/IEC60529. It is very important to protect against electrical hazards, especially as voltages increase.
Circuit Parameters
The electrical parameters are critical to evaluate when selecting fuses and fuse accessories. Voltage ratings are important during both normal operating conditions (nominal current) and also during the opening. The maximum voltage rating during operation is generally defined by the standard it is evaluated to.
Factors include but are not limited to, the dielectric strength of materials, voltage creepage between conductive surfaces and voltage clearances to conductive surfaces, as well as additional conditions of acceptability.
How to install a fuse holder?
To install a fuse holder, you’ll need the appropriate tools for the job. This includes an amperage-rated fuse holder, as well as wire cutting and stripping pliers, crimping pliers, butt-splice crimp connections, and so on.
Once all the necessary supplies are gathered up, be sure to carefully follow these steps:
1. Disconnect your device’s power cord from the electrical socket.
2. Using the wire-cutting pliers, snip the positive wire closest to your circuit.
3. Using a pair of wire-stripping pliers, trim a quarter inch from both the fuse holder and the split wires. Be sure to keep these tight when stripping them from the ends so as not to cause any damage to the fuse’s internal components.
4. It is important to spiralize the stripped ends of the circuit wires for maximized solidity and connectability.
5. The butt-splice crimp connector should be employed for wiring the twisted circuit wire. Utilizing crimping pliers is necessary for completing this task.
6. To properly secure the fuse holder wires into the butt-splice connection, use crimping pliers on either end. Ensure the connections are firmly secured at both ends for optimal performance.
7. Gently twist the leading device wire and insert it into a butt-splice connector. Be sure to securely hold the wire in place as you make the connection.
8. The opposite end of the fuse holder should be twisted, inserted into the butt splice attached to the wiring running towards the device, and then secured with a crimped clip.
9. Before combining the two sections and securing them, it is vital to fill the fuse holder with the appropriate amperage fuse. Failing to do so could have serious repercussions.
10. Troubleshoot the power source for your device.
Conclusion
Fuse holders are used to mount, contain, and protect fuses. There are two main types of fuse holders: open and fully enclosed. Fuse clips, fuse boxes, sockets, and plug covers are examples of open fuse holder types. Fully enclosed models may have other methods of fully enclosing the fuse, such as placing the fuse carrier in a bracket. If you want to learn more about fuse holders, please contact us at [email protected] or visit www.bituoelec.com.