Overview
The Reliance ECNR-1/2 RK5 0.5A fuse is a dual-element, time-delay cartridge fuse engineered for use in AC power distribution system mains, feeders, and branch circuits with inductive loads (motors, transformers) or non-inductive loads (lighting, heating). These fuses are recommended for AC power distribution system mains, feeders and branch circuits having inductive loads (motors, transformers) or non-inductive loads (lighting, heating) where the available short-circuit current does not exceed 200,000 RMS symmetrical amperes. The unit provides current-limiting protection and meets UL Class RK5 standards for industrial automation and electrical control applications.
Key Features
- Dual-Element Time-Delay Design: These dual element, time-delay fuses have minimum industry standard time-delay of 10 seconds at 5 times the fuse rating (8 sec. minimum for 250V, 30A and less).
- Current Limiting: RK5 Fuse class provides current limiting protection with 200kA RMS Sym. interrupting rating at rated voltage.
- Improved Load Sizing: The time-delay characteristics of these fuses typically allows them to be sized closer to the running ampacity of inductive loads to reduce cost and provide improved overcurrent protection.
- UL and CSA Certified: UL Listed, Class RK5, Guide JDDZ, File E162363 and CSA Certified HRCI-R per C22.2, No. 248.12
- Ferrule Cartridge Style: Standard cylindrical design for use with ferrule-type fuse holders common in motor control panels and distribution equipment.
- Package of 10: Box of 10 fuses for stock replacement and bulk inventory management.
Technical Specifications
- Ampere Rating: 0.5A
- Voltage Rating: 250VAC
- Fuse Class: RK5
- Type: Dual-Element Time-Delay (Current-Limiting)
- Interrupting Rating: 200,000 RMS symmetrical amperes
- Interrupting Rating (DC): 20,000 amperes DC
- Body Style: Cylindrical ferrule cartridge
- Length: 2.0 inches (ferrule design)
- Diameter: 9/16 inches maximum
- Certifications: UL Listed (Guide JDDZ, File E162363), CSA Certified per C22.2 No. 248.12, Class 1422-02
- Package: Box of 10 fuses
Typical Applications
- Motor control and protection circuits (125% FLA sizing capability)
- AC power distribution feeders and branch circuits
- Industrial automation equipment with inductive loads
- Transformer protection in control panels
- Lighting and heating circuit protection
- Machine tool and manufacturing equipment protection
Compatibility & Replacements
Compatible With
- All standard ferrule-type fuse holders rated for RK5 Class cartridge fuses
- AC power distribution equipment rated for 250VAC
- Motor control centers and switchgear with Class RK5 fuse clips
- Industrial automation control panels and distribution boards
- Equipment requiring RK5 dual-element time-delay protection
Replaces / Drop-In Replacement For
- ECNR-1/2 (Edison/Bussmann equivalent part number)
- Bussmann FRN-R-1/2 time-delay fuse (functionally equivalent)
- Mersen TR-1/2 dual-element fuse
- Littelfuse FLNR-1/2 time-delay cartridge fuse
- Verify compatibility with your system integrator or equipment manufacturer before ordering.
Works With
- RK5 Class fuse holders and clips (ferrule design)
- UL 248-12 compliant electrical distribution systems
- CSA-certified industrial control equipment
- Standard North American AC power distribution panels and motor control centers














