Fuses for Weidmuller Fused Terminal Blocks

Fuse Types

There are many types of small fuses that can be used in DIN rail-mounted terminal blocks. The most common types include:

• Glass cartridge fuses, 5mm x 20mm
• Ceramic cartridge fuses, 5mm x 20mm
• Pop-up indicating fuses, 5mm x 25mm
• Glass cartridge fuses, ¼” x 1-¼”
• Ceramic cartridge fuses, ¼” x 1-¼”
• Various other specialty size and shape fuses

Glass cartridge fuses are somewhat more fragile than their corresponding ceramic counterparts, however you can often readily identify a blown fuse if the casing is glass.

Fuses are also categorized by the speed at which they will blow (or interrupt the current). They are grouped according to the categories (F)ast, (M)edium, and (S)low. While using fuses with a “Slow” rating will help prevent nuisance circuit interruptions, they may allow a high current to flow through the circuit for a short time and cause damage to the system. Use care when select the amperage rating of the fuse and the speed rating. The design engineer should usually consult the “Time Current Curve” when making fuse size determination. Always insure that the fuse rating is less than the terminal block rating.

Fused Terminal Block Installation

The most common installation method for fused terminal blocks is to either:

• Snap the fuse into a removable component or hinged top lever. This portion is then inserted into the lower portion of the terminal block and provides circuit continuity, or
• Drop the fuse into a slot and screw a cap onto the top. This provides circuit continuity. This method is required for using the 5mm x 25mm pop-up style fuses. In this case, the cap has a viewing window to see when the pin pops up. When the fuse blows, it releases a spring and a colored pin on the end of the fuse will extend and be visible in the viewing window.

The 5mm x 20mm fuses can be used in the following terminal block types:

• SAKS 1
• SAKS 7
• ASK 1
• WSI 6
• KDKS 1
• ZSI 2.5

The 5mm x 25mm indicating fuses (pop-up) can be used in the following terminal block types. However, the blown fuse will not be visible from the outside of the terminal block if there is no viewing window. For example, the ASK 1 and WSI 6 levers must be opened to see if the fuse is blown.

• SAKS 1
• SAKS 7
• ASK 1
• WSI 6
• ZSI 2.5

The ¼” x 1-1/4” fuses can be used in the following terminal block types:

• SAKS 3
• SAKS 6
• WSI 6/2
• WSI 4
• ZSI 2.5/2

The 13/32” x 1-1/2” fuses can be used in the following terminal block:

• WSI 25
• SAKS 4

Fuse Selection

Click Here for a selection table of the fuses stocked at SCS (including size, voltage, and part number).

Fuses in Inventory

SCS currently stocks a broad selection of Weidmuller fuses along with the following types of Bussman fuses:

Size Type

5mm x 20mm, including the following types:

• GDB
• GDC
• GMA
• GMC

¼ x 1-1/4”, including the following types:

• AGC
• ABC
• MDL
• MDA

13/32 x 1-1/2”, including the following types:

• KTK
• KTK-R
• FNQ
• FNQ-R

Fuse Time-Current Curves

Click Here to see the fuse Time-Current curves for the Bussman fuses that are normally stocked at SCS