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Mersen Tri-Onic TRS-R Class RK5 Time-Delay Fuse, 600VAC/600VDC
The Mersen Tri-Onic® TRS-R is a current-limiting, time-delay fuse in Class RK5, engineered for overcurrent protection of motors, transformers, service entrance equipment, feeders, and branch circuits. Rated 600VAC and 600VDC with an AC maximum interrupting rating of 200 kA, this fuse rides through the harmless starting and inrush currents typical of motors and transformers instead of nuisance-tripping on momentary surges. The TRS-R family is available with a choice of termination style — Blade or Ferrule — so it can be matched to the mounting configuration of the fuse holder or disconnect being used, while every version shares the same PolyTube body construction, Class RK5 time-delay characteristic, and 50/60 Hz frequency rating. Whether specifying a blade-style unit for standard clip mounting or a ferrule-style unit for compact fuse blocks, electricians and engineers get consistent, code-compliant overcurrent protection across the line.
Key Features
- Fuse Class: Class RK5 construction for reliable, code-compliant overcurrent protection.
- Time-Delay Characteristic: Engineered to hold through harmless motor starting and transformer inrush currents while still clearing genuine overloads promptly.
- Dual Voltage Rating: Rated 600V AC (UL) and 600V DC (UL), giving flexibility across both AC and DC circuits.
- High Interrupting Capacity: 200 kA AC maximum interrupting rating/breaking capacity (I1) for demanding fault-current environments.
- Selectable Termination: Offered in Blade or Ferrule connection styles to fit the specific clip or block hardware in the installation.
- Durable Body Construction: PolyTube insulating body material supports consistent performance in service entrance and feeder applications.
- Frequency Rating: Rated for 50/60 Hz systems, suitable for standard AC power distribution.
Certifications & Compliance
- RoHS Compliant
Technical Specifications
- ROHS Compliant: Yes
- Connection Type: Blade or Ferrule (selectable)
- AC Max I.R./Breaking Capacity (I1): 200 kA
- Frequency: 50/60 Hz
- Rated Voltage AC (UL): 600 V
- Rated Voltage DC (UL): 600 V
- Speed/Characteristic: Time Delay
- AC or DC: AC/DC
- Body/Insulating Material: PolyTube
- Packaging: 1 EA
Typical Applications
- Motor Overcurrent and Branch-Circuit Protection
- Transformer Feeder Protection
- Service Entrance Equipment Protection
- Commercial and Industrial Feeders
- Panelboard and Switchboard Circuits
Why Mersen?
Mersen's Tri-Onic® TRS-R fuse combines Class RK5 current-limiting performance with a 200 kA interrupting rating and a rugged PolyTube body, giving electricians and engineers dependable time-delay protection for motors, transformers, and feeders. Available in Blade or Ferrule termination to suit the mounting hardware on hand, the dual 600VAC/600VDC rating and RoHS-compliant construction make it a versatile, code-conscious choice for professional electrical installations that demand consistent, reliable overcurrent protection.
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:
- 600 V
- Speed/Characteristic:
- Time Delay
- AC or DC:
- AC/DC
- Rated voltage DC UL:
- 600 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:
- 600V
- Series:
- Tri-Onic TRS-R
- Configuration:
- Time Delay
- Standards:
- RoHS Compliant
- Product Subgroup:
- Fuses
Mersen TRS1R – Frequently Asked Questions
1) Will a Mersen TRS-R fuse drop into my existing Class R fuse clips?
The Tri-Onic TRS-R is a Class RK5 fuse built for clip mounting, so it goes into standard Class R clips and rejection-style fuse holders. The thing to match is termination style: the TRS-R line comes in a ferrule version (TRS1R) for small ferrule-type blocks and a blade version (TRS450R) for bolted or knife-blade clips. Ferrule and blade are not interchangeable in the same holder, so order to the hardware you actually have in the disconnect.
2) Can I use the Mersen TRS-R on a DC circuit as well as AC?
Yes. The TRS-R carries a 600V AC and a 600V DC UL rating, so it works on both. The 200 kA figure is the AC maximum interrupting rating; it applies to AC fault duty, not DC. Frequency rating is 50/60 Hz for AC distribution.
3) Why does my motor fuse keep blowing on startup, and will a time-delay RK5 fix it?
A fast-acting fuse sized close to full load current will open on the inrush a motor or transformer draws at startup. The Tri-Onic TRS-R is a time-delay Class RK5, built to ride through that momentary surge while still clearing a real overload or fault. That is what makes it the usual choice for motor branch circuits, transformer feeders and service entrance gear.
4) What is the difference between the Mersen Tri-Onic TRS-R and the Littelfuse CCMR040 for motor branch-circuit protection?
Both are time-delay fuses sized to ride through motor starting current, but they are different fuse classes and different mounting hardware. The Tri-Onic TRS-R is a Class RK5 time-delay fuse rated 600VAC and 600VDC with a 200 kA AC interrupting rating, and it mounts in clips in either blade or ferrule termination. The Littelfuse CCMR040 is a Class CC time-delay fuse at 40A, which uses the much smaller Class CC rejection-style block rather than R-class clips. If the disconnect or switch is built for R-class fuses, the TRS-R is the one that fits; a Class CC holder will not take an R-class body.
5) Can a Littelfuse BLF midget fuse be used in place of a Mersen TRS-R?
No. The Littelfuse BLF is a midget fast-acting fuse rated 250V in a laminated tube body, so it differs from the TRS-R on three counts that matter: it is fast-acting rather than time-delay, it is rated 250V where the Tri-Onic TRS-R carries 600VAC and 600VDC, and the midget body does not seat in R-class clips. A fast-acting midget on a motor circuit will open on normal inrush, which is exactly what the TRS-R time-delay element is built to ride through.
6) I need a time-delay fuse for a DC circuit - does the Littelfuse CCMR040 work, or do I need the Mersen TRS-R?
The Mersen Tri-Onic TRS-R carries a UL DC rating of 600V alongside its 600VAC rating, so it is listed for both AC and DC service. The Littelfuse CCMR040 is a Class CC time-delay fuse at 40A. Where the application is DC and the equipment accepts R-class clips, the TRS-R is the one to specify, and it is offered in blade or ferrule termination to match the holder.
7) Is a 200 kA interrupting rating enough for my service entrance panel?
200 kA AC is the top of the normal range for low-voltage distribution fuses, and it covers service entrance and feeder locations where available fault current is high, such as close to a large utility transformer. Compare it against the available fault current calculated for your service; if that number is at or under 200 kA at 600V or less, the TRS-R is rated for the duty.
8) What is the difference between the blade and ferrule versions of the Mersen TRS-R?
Only the end connection. The ferrule style (TRS1R) has cylindrical end caps that seat in spring clips on compact fuse blocks, typical of lower ampere ratings. The blade style (TRS450R) has flat knife blades for the heavier clips used at higher ratings. Body construction, the RK5 time-delay characteristic, the 600VAC/600VDC rating and the PolyTube body are the same either way.
9) Should I use a Class RK5 fuse or a Class CC fuse for motor protection?
They solve the same problem at different sizes. The Mersen TRS-R is Class RK5 at 600VAC/600VDC with a 200 kA AC interrupting rating, and it mounts in standard Class R clips, which is what most 600V disconnects and panel fuse blocks are built for. Class CC is a physically much smaller midget-body fuse used in control circuits and compact motor controllers; ZenSupply carries the Littelfuse CCMR040 Class CC time-delay fuse for those. The two are not interchangeable in a holder, so the holder decides the class.
10) Is a Littelfuse AGU or AGA glass fuse an equivalent to the Mersen Tri-Onic TRS-R?
They are not interchangeable. The Littelfuse AGU and the AGA series, such as the 5A AGA5, are small glass tube fuses used for low-current electronic and automotive-style circuits. The Tri-Onic TRS-R is a Class RK5 branch-circuit and feeder fuse with a PolyTube body, 600VAC/600VDC rating, and a 200 kA AC interrupting rating for fault-current duty in service entrance and panelboard equipment. For motor, transformer, and feeder protection in a disconnect, the TRS-R is the correct class of device; a glass tube fuse is not rated for that service.
11) My metering circuit needs 600V fuses - should I order the Tri-Onic TRS-R or the Square D PowerLogic fuse pack?
For the metering circuit itself, the Square D PowerLogic Energy Meter Fuse Pack is the purpose-built option: it ships as a set of three 0.5A 600V fuses sized for meter potential leads. The Mersen Tri-Onic TRS-R shares the 600V class but is a Class RK5 time-delay power fuse for motor, transformer, feeder, and service entrance protection, mounted in clips. Use the PowerLogic pack on the meter inputs and the TRS-R on the power circuit it is measuring.
12) Does the Mersen TRS-R meet RoHS for a facility that requires it?
Yes, the Tri-Onic TRS-R is RoHS compliant, which is the compliance statement carried for the line. That matters for institutional and government specs that call out RoHS on electrical components.
13) Does the Mersen TRS-R come in a pack or as a single fuse?
Packaging is 1 each, so you are ordering individual fuses. On a three phase feeder or disconnect you need three, so order quantity to the number of poles rather than assuming a set.
14) What is the TRS-R fuse body made of and does it hold up in a hot panel?
The body is PolyTube insulating material, the construction Mersen uses across the Tri-Onic TRS-R line for service entrance and feeder duty. Both the ferrule and blade versions share it.
How fast can I get the Mersen TRS1R delivered?
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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 TRS1R come with a warranty?
Absolutely. The Mersen TRS1R is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
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