FOR SALE IS ONE (1) NEW 50 amp HEAVY DUTY DUAL ELEMENT TIME DELAY 250Vac/125Vdc FRN-R-50 CARTRIDGE STYLE FUSE BY FUSETRON COOPER BUSSMANN MPN FRN-R-50 UPC# 051712101806. THIS 3" length CARTRIDGE STYLE FUSE IS TYPICALLY USED TO PROTECT MOTORS AND BRANCH CIRCUITS WHERE HIGHER AMPS OR VOLT RATINGS ARE REQUIRED. THIS CLASS RK5 HEAVY DUTY FUSE HAS THE TIME DELAY FEATURE, ALLOWING MOMENTARY MOTOR STARTUPS. WHEN SIZED CORRECTLY, HELPS PROTECT MOTORS FROM BURNOUT CAUSED BY OVERLOADS OR SINGLE PHASING. THE TIME DELAY FEATURE ALLOWS THE INITIAL STARTUP CURRENT SURGE FOR TYPICAL MOTORS TO PASS, BUT OPENS PRIOR TO MOTOR BURNOUT WHEN LONGER, DANGEROUS OVERLOADS ARE PRESENT. IN ADDITION, THE DUAL ELEMENT DESIGN OPENS IN AS LITTLE AS 0.004 second IF THE FUSE EXPERIENCES SHORT CIRCUIT CONDITIONS. THIS FUSE IS UL LISTED (see agency information below). GROOVE IN END CAP PERMITS USAGE OR THE OPPORTUNITY TO UPGRADE IN CLASS K5 AND CLASS H FUSE BLOCKS AND HOLDERS. YOU WILL RECEIVE ONE (1) FRN-R-50 CARTRIDGE FUSE BY COOPER BUSSMAN SHIPPED FAST BY USPS FIRST CLASS MAIL..... AGENCY INFORMATION..... CE, Std. 248-12, Class RK5, UL Listed, Guide JDDZ, File E4273, CSA Certified, Class 1422-01, File 53787 note..... THIS RK5 CLASS FUSE BY COOPER BUSSMANN PROVIDES MOTOR OVERLOAD, GROUND FAULT AND SHORT CIRCUIT PROTECTION. THIS FUSE HELPS PROTECT MOTORS AGAINST BURNOUT FROM SINGLE PHASING ON THREE PHASE SYSTEMS. SIMPLIFIES AND IMPROVES BLACKOUT PREVENTION (selective coordination). THIS DUAL ELEMENT FUSE MAY BE APPLIED IN CIRCUITS SUBJECT TO TEMPORARY MOTOR OVERLOADS AND SURGE CURRENTS TO PROVIDE BOTH HIGH PERFORMANCE SHORT CIRCUIT AND OVERLOAD PROTECTION. THE OVERLOAD ELEMENT PROVIDES PROTECTION AGAINST LOW LEVEL OVERCURRENT OF OVERLOAD AND WILL HOLD AN OVERLOAD WHICH IS FIVE TIMES (5X) GREATER THAN THE AMPERE RATING OF THE FUSE FOR A MINIMUM OF TEN SECONDS..... BID AND BUY HERE IN IN ABSOLUTE CONFIDENCE SINCE I HAVE THOUSANDS OF POSITIVE FEEDBACK AND TEN+ YEARS EXPERIENCE. I SHIP WITHIN TWO DAYS OF RECEIPT OF PAYMENT, OFTEN THE NEXT DAY. $3.21 USPS FIRST CLASS GREEN SHIPPING USING RECYCLED PACKAGING MATERIALS AND ENVIRONMENTALLY FRIENDLY MATERIALS TO ANYWHERE USA. I DO NOT SHIP ANYWHERE ELSE. HAVE A GREAT DAY AND THANK YOU FOR STOPPING BY.......