{"product_id":"cooper-bussmann-frn-r-40-cartridge-time-delay-fuse-rk5-40a","title":"Cooper Bussmann FRN-R-40 Cartridge Time Delay Fuse RK5 40A","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe COOPER BUSSMANN FRN-R-40 is a Class RK5 cartridge-style time delay fuse rated at 40 amps, designed for general-purpose overcurrent protection in industrial, commercial, and HVAC applications. It measures 3 inches (76.2 mm) overall length and 20.6 mm in diameter, making it a standard dual-element cartridge fuse that fits conventional fuse holders. The two-element construction allows it to tolerate motor inrush and startup surges without nuisance tripping while still clearing sustained fault currents. Licensed electricians and HVAC technicians install this fuse when protecting motor loads, disconnect switches, and branch circuit equipment.\u003c\/p\u003e\u003cp\u003eThis fuse is suited for branch circuit and feeder protection where time delay characteristics are required to ride through motor starting loads. Typical applications include compressor disconnects, air handler units, pump motors, and panel board branch circuits in residential and light commercial systems. The non-indicating body gives no visual blown indication, so a fuse tester or multimeter is the appropriate diagnostic tool during service calls.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eClass RK5 time delay rating accommodates motor inrush without nuisance opens\u003c\/li\u003e\n\u003cli\u003eDual-element cartridge design for reliable overcurrent and short-circuit protection\u003c\/li\u003e\n\u003cli\u003e40-amp continuous current rating for branch circuit and motor load applications\u003c\/li\u003e\n\u003cli\u003eNon-indicating body — no internal blow indicator\u003c\/li\u003e\n\u003cli\u003eFuse holder mount type for standard cartridge fuse blocks and disconnects\u003c\/li\u003e\n\u003cli\u003eCE Certified, CSA Certified (C22.2 No. 248.12), and UL Listed (248-12 Class RK5)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as a direct-fit replacement for Class RK5 cartridge fuse holders and disconnect blocks that accept a 3-inch by 20.6 mm cartridge fuse at 40 amps. Verify fuse holder ampere and voltage ratings before installation.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eA licensed electrician should perform fuse replacement in accordance with the NEC and any applicable local codes. De-energize and lock out the circuit at the upstream breaker or disconnect before removing or installing the fuse. Use an insulated fuse puller rated for the voltage and current class — never remove a cartridge fuse by hand or with uninsulated tools. Confirm the replacement fuse class, ampere rating, and voltage rating match the original equipment specifications before restoring power.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuse Class\u003c\/strong\u003e: RK5\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuse Type\u003c\/strong\u003e: General Purpose\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAmperage\u003c\/strong\u003e: 40 amps\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuse Timing\u003c\/strong\u003e: Time Delay\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuse Body Type\u003c\/strong\u003e: Cartridge\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Elements\u003c\/strong\u003e: 2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndicating\u003c\/strong\u003e: Non-Indicating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 3 inches (76.2 mm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Diameter\u003c\/strong\u003e: 20.6 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMount Type\u003c\/strong\u003e: Fuse Holder\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInterrupt Rating\u003c\/strong\u003e: 20 kA at DC 200 RMS\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.12 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCertifications\u003c\/strong\u003e: CE Certified; CSA C22.2 No. 248.12 Class 1422-02 File 53787; UL Listed 248-12 Class RK5 Guide JDDZ File E4273\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUNSPSC Code\u003c\/strong\u003e: 39121605\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: COOPER BUSSMANN\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: FRN-R-40\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"EATON","offers":[{"title":"Default Title","offer_id":51695248572722,"sku":"FRN-R-40","price":302.23,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/f0d0631267b0f4cd7caa7eb7acf93c7b.jpg?v=1788333128","url":"https:\/\/voomisupply.com\/products\/cooper-bussmann-frn-r-40-cartridge-time-delay-fuse-rk5-40a","provider":"Voomi Supply","version":"1.0","type":"link"}