Modern machine tools are tough, complicated devices that deliver precision cutting and shaping through a series of complex movements and operations. As complex as they may be, there are a variety of small factors that can bring their production screeching to a halt. One of those factors is a failed fuse. A failed, or blown fuse can result in a downed machine that could cost hundreds, if not thousands, of dollars.
So, what is a fuse? And more importantly, why is it so important to make sure that the correct fuse type is installed in your machine?
At its core, an electric fuse acts as a measure of safety to protect electronics and wiring from excessive over current. This prevention against over-current protects the machine from bigger issues, such as damaged electrical components, complete machine failure, or shop fires.
When researching different fuse types to determine the correct one for you, it’s always a good idea to first consider suggested manufacturer specifications. Sometimes, however, a custom or retrofit machine requires something more closely aligned to the engineering involved. It is important to pay close attention to these factors in order to select the best fuse for your application. Fuse ratings should be just slightly more than the current which the application will draw under normal circumstances. The following factors should be considered when selecting the correct fuse:
1. Normal operating current
2. Application voltage (AC or DC)
3. Ambient temperature
4. Overload current and length of time in which the fuse must open
5. Maximum available fault current
6. Pulses, Surge Currents, Inrush Currents, Start-up, Currents, and Circuit Transients
7. Physical size limitations, such as length, diameter, or height
8. Agency Approvals required, such as UL, CSA, VDE, METI, MITI or Military
9. Fuse features (mounting type/form factor, ease of removal, axial leads, visual indication, etc.)
10. Fuse-holder features, if applicable and associated rerating (clips, mounting block, panel mount, PC board mount, R.F.I. shielded, etc.)
11. Application testing and verification prior to production
When removing a blown fuse and installing a new one, always ensure that the main power is turned off and all applicable safety procedures are followed. Be sure to connect the fuses to a live source in order to prevent the application from drawing any power after failure. Not doing so can result in electrical fires and possibly bodily injury.
