Industrial Fuses - Current Limiting Class RK1 Fuses

LENRK/LESRK series fuses have up to 40% more current limitation and up to 350% more Amps-Squared-Second (I²t) limitation under fault conditions than ECNR/ECSR series fuses, reducing the potential for damage. They also offer a better selection for electrical power system designers and superior short circuit protection for breakers having inadequate interrupting ratings. ECNR/ECSR and LENRK/LESRK fuse lines are physically interchangeable (and electrically interchangeable per U.L. equipment listing conditions). We recommend them as a practical, economical way to upgrade systems in many situations.

Current ratings up to 600 amps on RK1 current limiting fuses!

A Current-Limiting Fuse meets the following three conditions:

1. Interrupts all available overcurrents within its interrupt rating.



2. Within its current limiting range, limits the clearing time at rated voltage to an interval equal to, or less than, the first major or symmetrical current loop duration.



3. Limits peak let-through current to a value less than the available peak current.

Select the "Technical Info" tab above (or see our catalog) to refer to the fuse selection guide, which includes a general summary of the specifications included for each fuse type.

This selection guide does not include the many variables that can exist for specific situations such as local codes, unusual temperature, or other operating conditions.

When selecting fuses, be sure to comply with any applicable PUBLIC SAFETY standards that apply to Overcurrent Protection Devices (OPD).

Class RK1 Fuses Overview

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LENRK Series - Class RK1 Dual Element Time Delay Fuses Applications Recommended for AC power distribution system mains, feeders, and branch circuits Protection of motors and motor branch circuits Type 2 protection for IEC components All general-purpose applications including lighting, heating and other non-inductive loads Features: True dual - element spring - trigger construction allows sizing of 125% FLA for motor backup protection Superior overload and cycling capabilities Extremely current limiting; provides superior short circuit component protection Specifications Time Delay Voltage Rating: LENRK - 250 VAC Ampere Rating: 10 - 600 Amps Interrupting Rating: 200,000 RMS Symmetrical Amps Self-Certified Interrupting Rating: 300,000 RMS Symmetrical Amps Current Limiting: RK1 Fuse Self-Certified DC Ratings: - Voltage Rating: LENRK (.2-600) 125 VDC - Self-Certified Interrupting Rating: LENRK 20,000 Amperes DC Agency Approvals UL Listed, Class RK1, Guide JDDZ, File E162363 CSA Certified HRCI-R per C22.2, No. 248.12

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LESRK Series - Class RK1 Dual Element Time Delay Fuses Applications Recommended for AC power distribution system mains, feeders, and branch circuits Protection of motors and motor branch circuits Type 2 protection for IEC components All general-purpose applications including lighting, heating and other non-inductive loads Features: True dual - element spring - trigger construction allows sizing of 125% FLA for motor backup protection Superior overload and cycling capabilities Extremely current limiting; provides superior short circuit component protection Specifications Time Delay Voltage Rating: LESRK - 600 VAC Ampere Rating: 5 - 600 Amps Interrupting Rating: 200,000 RMS Symmetrical Amps Self-Certified Interrupting Rating: 300,000 RMS Symmetrical Amps Current Limiting: RK1 Fuse Self-Certified DC Ratings: - Voltage Rating: LESRK (.25-30) 200 VDC, (35-600) 300 VDC - Self-Certified Interrupting Rating: LESRK 20,000 Amperes DC Agency Approvals UL Listed, Class RK1, Guide JDDZ, File E162363 CSA Certified HRCI-R per C22.2, No. 248.12