Bussmann FNM Series Time-Delay...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$29.16
Bussmann FNM Series Time-Delay Midget Fuse

Bussmann FNM Series Time-Delay Midget Fuse

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Model: FNM-3-1/2

In Stock (leaves warehouse same day if ordered before 3pm ET)

$29.16
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Bussmann FNM Series Time-Delay Midget Fuse

The Bussmann FNM Series is an Eaton Bussmann line of time-delay midget fuses rated 250V, available across a family of amperage ratings from 0.25 Amp through 40 Amp, including 0.25A, 0.8A, 1.125A, 1.4A, 3.5A, 4.5A, and 40A options. Each FNM fuse in this series is a dual-element, non-indicating fuse with ferrule end x ferrule end terminations for standard midget fuse holders and fuse blocks. Nickel-plated bronze endcaps provide corrosion resistance and consistent electrical contact in demanding commercial and industrial environments. As a standard-type FNM series fuse, this family is built for dependable overcurrent protection in branch circuit, motor, and control circuit applications where brief overload conditions—such as motor starting inrush—must be tolerated without nuisance opening. The compact midget form factor allows FNM Series fuses to fit space-constrained panelboards, disconnect switches, and control panels while maintaining reliable circuit protection across the full amperage range.

Key Features

  • Amperage Rating Range: available from 0.25 Amp up to 40 Amp, allowing the correct fuse to be matched to the specific branch, motor, or control circuit load.
  • Voltage Rating: 250V, suitable for standard low-voltage electrical distribution systems.
  • Time-Delay, Dual-Element Design: accommodates temporary overload conditions such as motor starting inrush current without nuisance fuse opening.
  • Ferrule End x Ferrule End Terminals: standard termination style for compatibility with midget fuse holders and fuse blocks.
  • Nickel-Plated Bronze Endcaps: deliver corrosion resistance and consistent, stable electrical contact over time.
  • Non-Indicating: standard construction without a visual blown-fuse indicator.
  • Compact Midget Form Factor: sized to fit standard midget fuse holders, fuse blocks, and disconnect switches where panel space is limited.
  • FNM Series, Standard Type: midget-body fuse form factor for compact panel and enclosure layouts, offered across a wide range of amperage options to cover multiple circuit protection needs.

Technical Specifications

  • Series: FNM
  • Amperage Rating: 0.25 Amp, 0.8 Amp, 1.125 Amp, 1.4 Amp, 3.5 Amp, 4.5 Amp, 40 Amp

Typical Applications

  • Branch Circuit Overcurrent Protection
  • Motor Circuit Protection Where Inrush Current Is Present
  • Control Circuit Protection
  • Commercial and Industrial Electrical Panels
  • Panelboard and Load Center Fuse Applications

Why Bussmann?

Bussmann is a trusted name in circuit protection engineering, and the Eaton Bussmann FNM Series time-delay midget fuse family reflects that reputation with a dual-element design that balances sensitive overcurrent protection with tolerance for normal, temporary overloads. Nickel-plated bronze endcaps deliver long-term corrosion resistance and stable electrical contact, while the ferrule end x ferrule end termination style ensures compatibility with standard midget fuse mounting hardware across every amperage option in the series. With ratings spanning 0.25 Amp to 40 Amp at 250V, dual-element time-delay construction, and a non-indicating standard design, the FNM Series gives electricians and facility maintenance professionals a dependable, code-compliant option for overcurrent protection in compact panel and enclosure layouts.

Manufacturer Resources

Product Specs

Product Type:
Time-Delay Fuse
Series:
FNM
Voltage Rating:
250V
Connection Type:
Ferrule End
Product Finish:
Nickel-Plated
Configuration:
Time-Delay, Dual-Element
Department:
Electrical
Product Subgroup:
Fuses
list_batch:
BUSS-20260919
Product Weight:
.2 pounds
Product Material:
Nickel-plated Bronze Endcap
Product Height:
1.44 inches
End Type:
Ferrule
Product Group:
Circuit Protection

Bussmann FNM-3-1/2 – Frequently Asked Questions

1) Will a Bussmann FNM fuse fit a standard midget fuse holder?
Yes. The FNM is a midget-body fuse with ferrule end x ferrule end terminations, so it drops into standard midget fuse holders, midget fuse blocks and disconnect switches. Body height is listed at 1.44 inches, which is the usual 13/32 x 1-1/2 inch class midget envelope electricians already have in panel. No bolt or blade prep is involved, the ferrules just clip in.
2) Can I use an FNM fuse on a motor circuit without it blowing on startup?
That is what the FNM is built for. It is a time-delay, dual-element fuse, so it rides through the brief inrush of a motor start instead of opening on it, while still clearing a sustained overload or a short. If you want a fuse that opens fast on any overcurrent, a time-delay element is the wrong choice and you want a fast-acting midget instead.
3) What voltage can Bussmann FNM fuses be used at?
FNM fuses are rated 250V, so they suit 120V and 240V low-voltage distribution, control transformers, and motor and branch circuits in that range. Do not apply them above 250V. If the circuit is 480V or 600V, you need a 600V-rated midget, not an FNM.
4) What amp ratings does the Bussmann FNM series come in?
Ratings span 0.25A through 40A. The orderable ratings are 0.25A (FNM-1/4), 0.8A (FNM-8/10), 1.125A (FNM-1-1/8), 1.4A (FNM-1-4/10), 3.5A (FNM-3-1/2), 4.5A (FNM-4-1/2) and 40A (FNM-40). The low fractional ratings are what you use on control transformer secondaries and instrument circuits; the larger ones go on branch and motor loads.
5) Does the FNM fuse have a blown-fuse indicator?
No. The FNM is a non-indicating fuse, so there is no pop-out pin or visual flag. Maintenance techs confirm an open element with a meter or a continuity check. If your crew relies on a visual indicator to troubleshoot a panel quickly, specify an indicating-type midget instead.
6) How do I order the right FNM part number for a 1-1/8 amp control circuit?
Bussmann writes the fractional ratings as fractions in the catalog number, which trips people up. 1.125A is FNM-1-1/8, 1.4A is FNM-1-4/10, 0.25A is FNM-1/4 and 0.8A is FNM-8/10. Amperage is the only thing you specify on an FNM, since the 250V rating, ferrule ends and time-delay element are the same across every rating.
7) Can I standardize one fuse type across the control panels in my facility?
The FNM line makes that practical: one holder style and one body size covers everything from a 0.25A instrument circuit up to a 40A branch, all at 250V with the same ferrule ends. Stock the holders once and carry only the amp ratings your panels actually use. The limit is voltage, anything above 250V has to come off a different series.
How fast can I get the Bussmann FNM-3-1/2 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Bussmann FNM-3-1/2 come with a warranty?
Absolutely. The Bussmann FNM-3-1/2 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Bussmann FNM-3-1/2?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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