JLLN125 - 125Amp Fuse Description
JLLN125 - 125Amp Fuse
Engineered for industrial environments where space is at a premium and fault protection can’t be compromised, the Littelfuse JLLN125 delivers high‑speed overcurrent protection in a compact form. With its 125 A rating and Class T fast‑acting response, this fuse is designed to safeguard drives, UPS systems, power distribution panels and control assemblies with confidence. The blade‑style/bolt‑in mounting makes installation simple, while the current‑limiting performance ensures downstream devices experience minimal stress during a fault. Whether you’re upgrading your panel or designing a new motor‑control cabinet, this fuse gives you dependable performance in a small footprint.
Key Features and Benefits
- 125 Amp Fast‑Acting Performance: Clears short circuits and overloads quickly to protect sensitive components.
- Space‑Saving Design: The Class T form factor is significantly smaller than many traditional size‑R fuses, freeing up panel space without sacrificing protection.
- Knife‑Blade / Bolt‑In Termination: Provides secure connection in industrial settings, helping maintain reliable continuity under tough conditions.
- Current‑Limiting Operation: Lets‑through energy is minimized during a fault, which helps reduce thermal and mechanical stress on downstream equipment—and prolongs system life.
- High Interrupting Ratings: Built to handle large fault currents — ensuring your system stays safe even when unexpected events occur.
Technical Specifications
- Ampere Rating: 125 A continuous.
- Voltage Ratings: 300 VAC and 125 VDC.
-
Interrupting Ratings:
- Up to 200,000 A at 300 VAC
- Up to 20,000 A at 125 VDC
- Response Type: Fast‑Acting (F).
- Mounting Style: Knife‑blade/bolt‑in construction (Class T cartridge form).
- Fuse Class Designation: UL Class T.
- Typical Size: Approx. 1.062″ diameter × 2.437″ length (for the 110–200 A section of the series).
Material Compliance and Certifications
- UL Listed: UL 248‑15 standard for Class T fuses.
- CSA Certified: For Canadian safety requirements.
- CE Marked: For international installations requiring CE compliance.
- RoHS Compliant: Free from restricted hazardous substances.
Where It Works Best
- Drive Panels & Motor Controls: Ideal for variable speed drives, motor starters and other control circuits where compact, high‑speed protection is critical.
- UPS / Inverter Systems: Perfect for backup systems, power conversion setups and any scenario where protecting electronics from destructive overcurrents matters.
- Compact Switchboards & Meter Stacks: Because of its reduced size, it fits well in tight enclosures or multi‑pole protection setups where panel space is limited.
- Main & Sub‑Panels in Commercial/Industrial Environments: Provides fast‑acting protection and robust interrupt capacity when used as the main protective element in a distribution system.
Use of Original Equipment Manufacturer (OEM) trademarks, names, and logos is for informational and identification purposes only. This does not imply any affiliation, sponsorship, endorsement, or approval by the original equipment manufacturer. All trademarks and registered trademarks are the property of their respective owners.
Specifications
- Width:1.062
- Depth:1.062
- Height:2.437
- Amperes:125
- A.I.C. Rating & Volts:200 kA @ 300 V.AC
- Type:JLLN
- Additional Notes:Knife-blade Style, Non-Indicating, Very Fast-Acting, current-limiting Class T Fuse
Returns are easy
You may return unused items within 30 days of delivery for a full refund.
FREE shipping on breaker orders over $100 and all other items with orders over $500.
CIRCUIT BREAKER SUPERSTORE® offers one to five day delivery in the United States. The variation depends on the chosen shipping speed and the warehouse location for the product(s).
Same Day Shipping
We strive to ship out your items within one business day.
In rare circumstances, CIRCUIT BREAKER SUPERSTORE® may reserve up to 5 business days to complete shipment. Feel free to contact us if your order is time sensitive.
CIRCUIT BREAKER SUPERSTORE® provides a limited 1-year warranty on both new and reconditioned products. Rest assured, all products are authentic OEM (original equipment manufacturer).

