Mersen TRM-210 Tri-Onic® Time-...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$21.84
Mersen TRM-210 Tri-Onic® Time-Delay Midget Fuse, 250VAC Ferrule

Mersen TRM-210 Tri-Onic® Time-Delay Midget Fuse, 250VAC Ferrule

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Model: TRM3-1/2

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

$21.84
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Mersen TRM-210 Tri-Onic® Time-Delay Midget Fuse, 250VAC Ferrule

The Mersen Tri-Onic® TRM Series is a family of Time-Delay Midget-class fuses rated 250V AC and available in ferrule-terminal, clip-mount configurations spanning ampere ratings from 1/10 to 30A. Within this platform, the Motor FLA selection covers 12 options — 0.2A, 0.3A, 0.4A, 0.8A, 1.125A, 1.6A, 1.8A, 2.5A, 2.8A, 3.5A, 4.5A, and 5.6A — letting you match the fuse precisely to the full-load amperage of the motor or transformer being protected. Every option in the family shares the same 12-second time-delay at 200% rating, a GMG body/insulating material, tin-plated copper Ferrule terminals, and a 10 kA AC interrupt rating, delivering dependable supplemental protection against high-inrush loads on small motors, small transformers, and other general 250V AC equipment. These fuses are intended for supplemental protection only and are not designed for Branch Circuit Protection.

Key Features

  • Motor FLA Options: 12 selectable full-load amperage ratings — 0.2A, 0.3A, 0.4A, 0.8A, 1.125A, 1.6A, 1.8A, 2.5A, 2.8A, 3.5A, 4.5A, and 5.6A — within the broader 1/10 to 30A TRM Series range, so the correct fuse can be matched to the connected load.
  • Time-Delay Characteristic: 12 seconds time-delay at 200% rating provides supplemental protection against motor and transformer inrush without nuisance opening.
  • Connection/Terminal Type: Ferrule terminals constructed of tin-plated copper for secure, low-resistance clip-mount installation.
  • Mounting: Clip mounting for straightforward installation and replacement in standard fuse holders and blocks.
  • AC Max I.R./Breaking Capacity: 10 kA interrupt rating (I1) for dependable fault clearing under high-fault-current conditions.
  • Voltage Rating: 250V AC, UL rated, within the Fuse Class Midget category.
  • Body/Insulating Material: GMG body/insulating material for consistent construction quality across the series.
  • Frequency: 50/60 Hz compatibility for standard AC power systems.

Certifications & Compliance

  • RoHS Compliant

Technical Specifications

  • ROHS Compliant: Yes
  • Speed/Characteristic: Time Delay
  • AC or DC: AC
  • Body/Insulating Material: GMG

Typical Applications

  • Supplemental Protection of Small Motors
  • Small Transformer Protection
  • High-Inrush Load Circuits
  • General 250V AC Equipment Protection
  • Commercial and Industrial Electrical Panels
  • Control Circuit and Component Protection

Why Mersen?

Mersen Tri-Onic® TRM Series fuses combine a GMG body/insulating material with tin-plated copper Ferrule terminals and clip mounting for dependable, code-aware performance across every Motor FLA option in this family. With a 10 kA interrupt rating, a 12-second time-delay at 200% rating, and RoHS-compliant construction, these Midget-class fuses deliver reliable service across small motor, transformer, and control circuit applications. Choose Mersen for consistent, professional-grade electrical components trusted in commercial and industrial installations, backed by ampere ratings spanning 1/10 to 30A to fit a broad range of 250V AC protection needs.

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Manufacturer Resources

Mersen Product Catalog

Product Specs

Connection Terminal Type:
Ferrule
Mounting Method:
Clip
Connection/Terminal Material:
Tin-Plated Copper
AC Max I.R./Breaking Capacity: I1:
10 kA
ROHS Compliant:
Yes
Frequency (Hz):
50/60 Hz
Speed/Characteristic:
Time Delay
Rated voltage AC UL:
250 V
AC or DC:
AC
Fuse Class:
Midget
Body/Insulating Material:
GMG
list_batch:
MERSEN-20260825
Department:
Electrical
Product Group:
Circuit Protection
Product Type:
Time-Delay Fuse
Product Material:
GMG
Voltage Rating:
250V
Amperage Rating:
1/10A - 30A
Connection Type:
Ferrule
Standards:
RoHS Compliant
Product Subgroup:
Fuses

Mersen TRM3-1/2 – Frequently Asked Questions

1) Can I use a Mersen Tri-Onic TRM midget fuse for branch circuit protection?
No. The Tri-Onic TRM Series is a supplemental protection fuse only, and is not designed for branch circuit protection. Use it downstream of a properly rated branch circuit device to protect small motors, small transformers, and control circuit components on 250V AC systems. If the fuse is the branch circuit protection on the drawing, you need a branch-rated class fuse instead, such as a Class CC time-delay like the Littelfuse CCMR Series.
2) How do I pick the right TRM fuse amp rating for my motor?
Size by the motor or transformer full-load amperage. The TRM selection runs 0.2A, 0.3A, 0.4A, 0.8A, 1.125A, 1.6A, 1.8A, 2.5A, 2.8A, 3.5A, 4.5A and 5.6A FLA, inside a wider TRM Series range of 1/10A to 30A. Each one carries the same 12 second time delay at 200% of rating, so the inrush of a small motor or transformer will not open it while the correct FLA match still gives you close supplemental protection.
3) Will a Mersen TRM fuse fit my existing midget fuse holder?
It should, if the holder is a clip-style midget holder. The TRM is a Midget class fuse with ferrule terminals and clip mounting, which is the standard 13/32 x 1-1/2 inch midget footprint used by midget blocks and holders. The ferrules are tin-plated copper for a low resistance connection in the clips.
4) Is a 10 kA interrupting rating enough for my panel?
The TRM carries a 10 kA AC interrupting rating, so the available fault current at the point of installation must be 10 kA or less. On small control panels and machine circuits fed through a transformer that is normally the case. If your short circuit study shows more than 10 kA at that point, step up to a higher interrupting class fuse rather than using a midget.
5) Can Mersen TRM fuses be used on a DC circuit or on 480V?
No to both. The Tri-Onic TRM is an AC-only fuse rated 250V AC at 50/60 Hz. It has no DC rating, and it cannot be applied at 480V. Keep it on 240V class and lower AC circuits.
6) Can I use a Littelfuse CCMR Class CC fuse instead of a Mersen TRM midget fuse?
Not interchangeably. The Littelfuse CCMR040 is a Class CC time-delay fuse rated 40A, and Class CC is a branch-circuit fuse class with its own rejection-style holder dimensions. The Mersen TRM is Midget class with ferrule terminals and clip mounting, and the TRM family is intended for supplemental protection rather than branch circuit protection. They share a time-delay characteristic but not a class, a holder, or an application role. If the drawing calls for branch circuit protection, a Class CC fuse such as the CCMR is the correct family; if it calls for supplemental protection of a small motor or control circuit, the TRM is.
7) Time-delay or fast-acting midget fuse for a small motor circuit?
Time delay, for anything with inrush. The Mersen TRM is a time-delay midget rated to hold 200% of its rating for 12 seconds, which is what keeps a motor or transformer magnetizing surge from blowing the fuse on every start. A fast-acting midget such as the Littelfuse BLF Series, 250V, is the right choice for resistive or electronic loads where you want the quickest clearing and there is no startup surge.
8) Which Mersen part number do I order for a 2.5 amp motor?
That is the TRM2-1/2. Mersen writes the fractional ratings as fractions in the part number, so 1.125A is TRM1-1/8, 1.6A is TRM1-6/10, 1.8A is TRM1-8/10, 2.8A is TRM2-8/10, 3.5A is TRM3-1/2, 4.5A is TRM4-1/2, 5.6A is TRM5-6/10, and the sub-amp sizes are TRM2/10, TRM3/10, TRM4/10 and TRM8/10. Order by the FLA you need and the part number follows.
9) Can I swap a glass automotive-style fuse like an AGU or AGA for a Mersen TRM?
Not interchangeably. The TRM is a Midget class, 250V AC, clip-mounted ferrule fuse for supplemental protection on commercial and industrial AC circuits. The Littelfuse AGA and AGU Series are glass tube fuses in different body sizes and are not midget-class replacements. Match the fuse class and holder size, not just the amp rating.
10) My panel needs a small fuse for a metering circuit, not a motor. Is the Mersen TRM the right pick?
The TRM Tri-Onic is built around inrush: 12 second time delay at 200% of rating, sized to motor full-load amperage from 0.2A up to 5.6A within a 1/10A to 30A series range, at 250V AC. A metering circuit has no inrush to ride through, and a dedicated meter fuse set such as the Square D PowerLogic energy meter fuse pack, supplied as a set of three rated 0.5A 600V, is the part built for that duty and for the higher 600V system voltage. Use the TRM where a small motor or transformer is starting against the fuse; use the metering fuse pack on the instrument circuit.
11) I need a midget fuse that opens fast for a solid-state load. What should I use instead of the TRM?
For a load with no starting inrush, the deliberate 12 second delay at 200% that the Mersen TRM provides is working against you. A fast-acting midget fuse in the same 250V midget footprint, such as the Littelfuse BLF series, is the alternative that keeps the midget holder and clip arrangement while dropping the time delay. Both are midget class at 250V, so the holder and block generally stay as-is; the change is purely the time-current characteristic.
12) Are Mersen Tri-Onic TRM fuses RoHS compliant for our facility spec?
Yes, the TRM Series is RoHS compliant, which covers the usual procurement requirement on restricted substances. Construction is a GMG body with tin-plated copper ferrules.
How fast can I get the Mersen TRM3-1/2 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 Mersen TRM3-1/2 come with a warranty?
Absolutely. The Mersen TRM3-1/2 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 Mersen TRM3-1/2?
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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