Mersen TR-9R Tri-Onic Class RK...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$32.70
Mersen TR-9R Tri-Onic Class RK5 Time-Delay Fuse

Mersen TR-9R Tri-Onic Class RK5 Time-Delay Fuse

(No reviews yet) Write a Review

Model: TR9R

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

$32.70
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

Mersen TR-9R Tri-Onic Class RK5 Time-Delay Fuse

The Mersen TR-9R Tri-Onic Class RK5 Time-Delay Fuse delivers current-limiting overcurrent protection for motors, transformers, service entrance equipment, feeders, and branch circuits. This Class RK5 fuse is rated 250V AC and 160V DC (UL) with a 200 kA AC maximum interrupting rating, giving electrical professionals dependable protection in demanding power distribution systems. The Tri-Onic TR-9R series is available with your choice of Blade or Ferrule termination, so the same time-delay performance and PolyTube insulating body construction can be matched to the connection style your fuseholder or fuseblock requires. Whether specified for Blade or Ferrule termination, every TR-9R fuse shares the same 50/60 Hz rating, RoHS compliance, and time-delay characteristic engineered to ride through harmless motor starting and transformer inrush currents without nuisance opening.

Key Features

  • Fuse Class: Class RK5 current-limiting, time-delay fuse for reliable overcurrent protection.
  • Rated Voltage: 250V AC / 160V DC (UL) for use across AC and DC circuits.
  • Breaking Capacity: 200 kA AC maximum interrupting rating (I1) for high fault-current applications.
  • Time-Delay Characteristic: Safely handles harmless motor starting and transformer inrush currents to avoid nuisance opening.
  • Connection Options: Available in Blade or Ferrule termination styles to match your fuseholder or fuseblock configuration.
  • Body Construction: PolyTube insulating body material for durable performance.
  • Frequency: Rated for 50/60 Hz applications.
  • Packaging: Supplied 10 EA per package for convenient stocking.

Certifications & Compliance

  • UL Rated Voltage: 250V AC / 160V DC
  • RoHS Compliant

Technical Specifications

  • Mounting: Clip
  • AC Max I.R./Breaking Capacity (I1): 200 kA
  • ROHS Compliant: Yes
  • Frequency: 50/60 Hz
  • Rated Voltage AC (UL): 250 V
  • Rated Voltage DC (UL): 160 V
  • Speed/Characteristic: Time Delay
  • AC or DC: AC/DC
  • Fuse Class: Class RK5
  • Body/Insulating Material: PolyTube
  • Connection Type Options: Blade, Ferrule
  • Packaging: 10 EA

Typical Applications

  • Motor Overcurrent Protection
  • Transformer Protection
  • Service Entrance Equipment
  • Feeder and Branch-Circuit Protection
  • Industrial and Commercial Power Distribution Systems

Why Mersen?

Mersen Tri-Onic TR-9R fuses pair a PolyTube insulated body with a 200 kA AC breaking capacity and UL-rated 250V AC/160V DC performance, giving electrical professionals dependable, code-compliant overcurrent protection for motors, transformers, and distribution equipment. Available in Blade or Ferrule connection styles, RoHS-compliant Class RK5 time-delay construction helps ensure safe operation through normal starting and inrush currents without unnecessary fuse opening. Shop Mersen electrical protection products at ZenSupply for specification-driven reliability you can trust on the job.

Manufacturer Resources

Mersen Product Catalog

Product Specs

Mounting Method:
Clip
AC Max I.R./Breaking Capacity: I1:
200 kA
ROHS Compliant:
Yes
Frequency (Hz):
50/60 Hz
Rated voltage AC UL:
250 V
Speed/Characteristic:
Time Delay
AC or DC:
AC/DC
Rated voltage DC UL:
160 V
Fuse Class:
Class RK5
Body/Insulating Material:
PolyTube
list_batch:
MERSEN-20260825
Department:
Electrical
Product Group:
Circuit Protection
Product Type:
Time-Delay Fuse
Product Material:
PolyTube
Voltage Rating:
250V
Series:
Tri-Onic
Standards:
RoHS Compliant
Product Subgroup:
Fuses

Mersen TR9R – Frequently Asked Questions

1) What is the difference between the Blade and Ferrule versions of the Mersen TR-9R Tri-Onic fuse?
It is purely the termination style, and it changes the part number you order. The Ferrule version is MPN TR9R; the Blade version is MPN TR450R. Electrical ratings, time-delay characteristic, and PolyTube body are the same on both. Pick the one that matches the fuseholder or fuseblock you already have: ferrule ends seat in a clip-style holder, blade ends bolt or clip to a blade-type block. Mounting on both is clip.
2) Will a Mersen TR-9R Class RK5 fuse work in a 480V panel?
No. The TR-9R is rated 250V AC and 160V DC (UL), so it must not be installed on a 480V system. For a 480V or 600V circuit you need a 600V class fuse (Class RK5 600V, Class J, or Class L depending on the equipment), not this 250V part.
3) Can I drop a Class RK5 fuse into a Class R fuseblock that currently has an RK1 fuse?
Mechanically, yes. Class RK5 and RK1 share the same Class R rejection body dimensions for a given amp rating and voltage, so a TR-9R fits a Class R rejection block rated 250V. The difference is performance: RK1 is lower let-through energy than RK5. If the panel schedule or the equipment label calls for a Class RK1 fuse to hold a specific short-circuit current rating, substituting RK5 can void that rating. Where the spec just says Class R or RK5, the TR-9R is the right part at 250V and 200 kA interrupting.
4) Is the Littelfuse CCMR040 a direct replacement for a Mersen TR-9R Tri-Onic fuse?
No. Both are time-delay fuses, but they are different fuse classes and different physical bodies. The Mersen TR-9R Tri-Onic is a Class RK5 time-delay fuse rated 250V AC and 160V DC with a 200 kA AC interrupting rating, mounted in clips and supplied in blade or ferrule termination. The Littelfuse CCMR040 is a Class CC time-delay fuse from the CCMR series, which uses the smaller midget-style Class CC body and rejection fuseholders. A Class CC fuse will not drop into an RK5 fuse clip or block, so choose the CCMR040 only where the equipment was built for Class CC holders.
5) Why use a time-delay fuse instead of a fast-acting one for a motor circuit?
Motors draw several times full-load current for the first seconds of starting, and transformers pull a brief inrush. The Tri-Onic TR-9R is a time-delay fuse, so it rides through that harmless surge instead of opening. A fast-acting fuse in the same spot nuisance-trips on every start. Fast-acting is what you want for protecting circuits with no inrush, such as electronics or resistive loads. If you need a fast-acting midget instead, ZenSupply carries the Littelfuse BLF Series midget fast-acting fuse at 250V.
6) Does a 200 kA interrupting rating matter for a service entrance fuse?
It does when available fault current at the service is high. The TR-9R is rated 200 kA AC maximum interrupting, which covers the available fault current at essentially any 250V service or feeder you will meet, and as a current-limiting Class RK5 fuse it also cuts the let-through energy reaching downstream gear. That is what lets you use it ahead of equipment with a series-rated short-circuit value.
7) I need a time-delay fuse but my holder is Class CC, not Class R. What should I use?
A Class R fuse like the TR-9R will not seat in a Class CC holder, the body styles are different. For a Class CC time-delay application ZenSupply carries the Littelfuse CCMR Series, including the CCMR040 at 40A. Stay with the TR-9R only where the block is Class R rejection at 250V.
8) Can a Littelfuse AGU or AGA glass fuse be substituted for a Mersen TR-9R?
No, these serve different jobs. The Littelfuse AGU is an AG-series glass tube fuse and the AGA5 is a 5A glass fuse from the AGA series, both small glass-body cartridge fuses used for low-current electronic and automotive-style circuits. The Mersen TR-9R Tri-Onic is a Class RK5 time-delay power fuse with a PolyTube insulating body, a 200 kA AC interrupting rating, and clip mounting, intended for motor, transformer, service entrance, and feeder protection. A glass fuse has neither the body form nor the fault-current capability for that service.
9) We need fuses for a PowerLogic energy meter, not a motor circuit. Is the Mersen TR-9R the right part?
No. Metering circuits take a small control-class fuse, and the Square D PowerLogic energy meter fuse pack is a set of three 0.5A 600V fuses made for that duty. The Mersen TR-9R Tri-Onic is a 250V AC / 160V DC Class RK5 time-delay power fuse for motor, transformer, service entrance, and branch-circuit protection, so its voltage rating and body style do not suit a 600V meter potential circuit.
10) Is the Mersen Tri-Onic TR-9R RoHS compliant for a specification that requires it?
Yes, the TR-9R is RoHS compliant, which is the compliance point most institutional and government specs ask about on fuses. It is also UL rated at 250V AC / 160V DC.
11) Will the Mersen TR-9R work on a 50 Hz system overseas?
Yes. The Tri-Onic TR-9R is rated 50/60 Hz, so it performs the same on either supply frequency.
12) How are Mersen TR-9R fuses packaged for stocking an MRO crib?
They ship 10 each per package, which suits keeping a shelf quantity for motor and feeder circuits rather than buying singles. Order by termination: TR9R for ferrule, TR450R for blade.
How fast can I get the Mersen TR9R 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 TR9R come with a warranty?
Absolutely. The Mersen TR9R 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 TR9R?
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
Why buy the Mersen TR9R from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
!