Okay...here"s the bad news...
Unlike fuses...NO manufacturer has EXACTLY the same panel-mounted fuse holder as another manufacturer. Bussmann"s fuseholders are not the same as Littelfuse"s fuseholders...or Schurter"s...or Belfuse"s...or OptiFuse"s...
There are slight cosmetic or functional variations among all of the various manufacturers that differentiate their fuseholders from one another...
Now the good news...
Most of the fuseholders are FUNCTIONALLY the same among the different brands...and interchangeable in many situations...
There are still the very basic specifications such as the voltage and current rating of the application and fuseholder. Beyond these two parameters there are some options that are available from most manufacturers.
Here is a basic run-down of the various parameters that an engineer or buyer should be aware of when looking to specify or cross panel-mounted fuseholders:
Type of Fuse
Panel mounted fuseholders are intended to mount 3 basic fuse types:
Finger Knob or Screwdriver Slot
- 3AG fuses (1/4" x 1 1/4")
- 5 x 20 mm fuses
- 5AG fuses (13/32" x 1 1/2" sometimes called midget fuses)
There are two basic designs: One that allows the user to remove the fuse with just their fingers and one that requires a tool (such as a screwdriver) to remover the top.
Screw Cap or Bayonet Cap
Screw caps provide superior water and condensation resistance (especially useful in outdoor applications) while a bayonet cap provides convenience of removing the cap with just a 1/4 turn. Screw or bayonet caps are available in both finger knobs and screwdriver slot configurations.
The mounting hole is the size of the cut-out needed to secure the fuseholder.
A typical mount hole is approximately 12.7 mm in diameter but can vary slightly for each manufacturer and/or part number.
Snap-in or Mounting Nut
Some manufacturers have fuseholders that allow them to be snapped into the mounting hole instead of fastening and tightening a rear nut to secure the fuseholder. The snap-in feature saves valuable production time for the OEM.
The metal terminals provide a points of connection into a circuit. The options are:
The solder tabs are used in higher current situations or in applications with a high amount of vibrations.
- 1/4" (0.250") Quick Connects
- 3/16" (0.167") Quick connects
- Solder Tabs
Straight or Right Angle Terminals
Lastly the end terminal can be straight or at a right angle.
In addition to some of the basic options, there are still other options to consider such as:
There are so many choices and configurations available. Now perhaps you can understand why manufacturer"s fuseholders vary slightly from one another.
- The overall length, the length in front of the panel (sometimes referred to as the profile height) or behind the panel
- Color-coded knob face
- Knurled-knob or fluted knob
- Plastic or metal mounting nuts
At OptiFuse, we currently offer over 50 different styles, shapes, and sizes to choose from. Allow us to discuss your individual application when the time arises for you to choose the fuseholder for your new project or want to evaluate a lower cost solution for your current application.
Thank you very much for your continued support of OptiFuse where each day we offer our knowledge to solve your problems...