FRS-R-40 TIME DELAY FUSE BUSSMANN

FRS-R-40 TIME DELAY FUSE BUSSMANN – Industrial 40A 600VAC/250VDC Class RK5 Dual-Element Time-Delay Fuse

The FRS-R-40 TIME DELAY FUSE BUSSMANN (Model FRS-R-40) is an energy-efficient, industrial-grade dual-element time-delay power fuse manufactured by Eaton’s Bussmann series. Engineered specifically to provide reliable branch circuit, motor overload, and short-circuit protection across commercial and industrial distribution networks, this $40text{-amp}$ , $600text{ VAC} / 250text{ VDC}$ Fusetron™ fuse delivers high-speed short-circuit clearing combined with high surge-handling capability.

Featuring a dual-element design, the FRS-R-40 TIME DELAY FUSE BUSSMANN provides a minimum 10-second time-delay at $500%$ of its rated ampacity. This extended time delay allows temporary, harmless motor starting currents and transformer inrush surges to pass safely without nuisance tripping. However, under high-energy short-circuit conditions, its current-limiting feature opens rapidly to interrupt faults up to $200text{ kA RMS}$ Symmetrical at $600text{ VAC}$ and $20text{ kA}$ at $250text{ VDC}$ . Built with a standardized Class RK5 rejection feature, it physically prevents lower-rated Class H or Class K fuses from being mistakenly installed into protected circuits.

As shown in the image, the fuse features a vibrant green cylindrical casing with a clear label reading “Bussmann FUSETRON™ ENERGY EFFICIENT DUAL-ELEMENT TIME-DELAY CLASS RK5 FUSE FRS-R-40 600Vac AC IR 200kA 250Vdc DC IR 20kA”, capped on both ends with conductive end caps featuring a Class RK5 rejection groove on the bottom ferrule.

Key Features of the FRS-R-40 TIME DELAY FUSE BUSSMANN

Dual-Element Time-Delay Performance: Delivers a minimum $10text{-second}$ time-delay at $500%$ rated current, absorbing motor startup inrush surges and preventing unnecessary downtime.
Class RK5 Rejection Feature: Built with a standardized Class RK5 rejection groove on the end cap that keys into Class R fuse blocks, preventing accidental over-fusing or substituting lesser-rated fuses.
High $200text{ kA}$ Interrupting Capacity: Fully rated to safely interrupt fault currents up to $200text{ kAIC}$ at $600text{ VAC}$ (and $20text{ kAIC}$ at $250text{ VDC}$ ), fulfilling NEC® Section 110.9 safety compliance requirements.
Current-Limiting Operation: Drastically restricts peak magnetic and thermal let-through energy under heavy fault conditions, protecting downstream contactors, breakers, and distribution panels.
Energy-Efficient Design: Engineered with low internal resistance to minimize watts loss and lower operating thermal loads inside electrical enclosures.
Dual $600text{V}$ AC / $250text{V}$ DC Rating: Highly versatile for installation across both high-voltage AC mains distribution and industrial DC power networks.

Common Applications and Practical Usage

The surge-tolerant time delay, high breaking capacity, and Class RK5 rejection profile of the FRS-R-40 TIME DELAY FUSE BUSSMANN make it a standard choice across heavy commercial and industrial power systems:

AC Motor Branch Circuits: Provides overload and short-circuit protection for industrial motors, pumps, fans, compressors, and HVAC equipment.
Main Feeder & Branch Panels: Safeguards commercial power distribution panels, service switches, and feeder circuits operating up to $600text{V}$ .
Transformer Primary & Secondary Protection: Safely handles heavy primary magnetizing inrush surges on power and distribution transformers.
Industrial Control Cabinets: Protects automated production lines, heavy-duty contactors, disconnect switches, and machine feeders.

Technical Specifications

The core electrical, physical, and compliance parameters for the FRS-R-40 TIME DELAY FUSE BUSSMANN are detailed below:

Parameter Specification	Technical Details & Operational Values
Component Classification	Industrial Class RK5 Dual-Element Time-Delay Fuse
Primary Target Keyword	FRS-R-40 TIME DELAY FUSE BUSSMANN
Brand / Series	Eaton Bussmann Series / Fusetron™ FRS-R
Catalog Model / Part No.	FRS-R-40
Amperage Rating	$40text{ Amps}$ ( $40text{A}$ )
Voltage Rating	$600text{ VAC}$ / $250text{ VDC}$
Interrupt Rating (IR)	$200text{ kA RMS}$ Symmetrical at $600text{ VAC}$ / $20text{ kA}$ at $250text{ VDC}$
Response Characteristic	Time-Delay (Min. $10text{ seconds}$ at $500%$ current)
Fuse Class & Form Factor	UL Class RK5 Ferrule with Rejection Ring ( $1-1/16'' times 5-1/2''$ )
Terminal Connection Type	Ferrule End Caps with Class RK5 Rejection Ring
Body Material & Color	Durable Fiberglass / Heavy Duty Tube with Green Label
Agency Certifications	UL Listed (Std 248-12, File E5227), CSA Certified, CE, RoHS Compliant

Operating Guidelines and Usage Tips

SAFETY NOTICE: Always isolate main power sources and verify circuits are fully de-energized using a calibrated voltage tester prior to inspecting or replacing power fuses.

Holder Compatibility: Install in dedicated UL Class R rejection fuse blocks (such as Bussmann RM600 series) or safety switches to ensure complete engagement of the Class RK5 rejection feature.

Motor Protection Sizing: Size fuses at $125%$ to $175%$ of motor full-load amps (FLA) according to NEC® Article 430 rules to balance inrush withstand capability with motor overload protection.

To review official Class RK5 low-voltage power circuit standards and current-limiting fuse guidelines, consult the National Electrical Manufacturers Association (NEMA) Directory.

To check regional warehouse inventory availability or request commercial quotes for volume electrical fuses, visit the Control Qatar Contact Page.

FRS-R-40 TIME DELAY FUSE BUSSMANN