LLSRK040ID - 40Amp Fuse

LLSRK040ID - 40Amp Fuse

When a fuse opens, the last thing a maintenance technician wants is to spend valuable time figuring out which one caused the interruption. That's where the Littelfuse LLSRK040ID 40 Amp Class RK1 time-delay indicating fuse makes a difference. Built for industrial and commercial electrical systems, this Powr-Pro fuse combines effective overcurrent protection with a convenient visual indicator that helps maintenance teams identify an opened fuse without unnecessary guesswork.

Whether you're maintaining industrial machinery, protecting electrical control equipment, or working with commercial power systems, the Littelfuse LLSRK040ID 40A indicating fuse offers a useful balance of protection and convenience. It handles an important job behind the scenes while making life a little easier when electrical problems arise.

Key Features and Benefits

• 40 Amp Continuous Current Rating
• 600V AC / 300V DC Voltage Ratings
• Class RK1 Current-Limiting Protection
• Patented Indicator™ Technology
• Darkening Blown-Fuse Indicator Window
• Time-Delay (Slo-Blo) Performance
• High Interrupting Capacity
• Precision-Formed Short-Circuit Elements
• Solid-State Overload Section
• No Moving Parts in the Overload Section
• Reduced Nuisance Openings

Technical Specifications

• Manufacturer: Littelfuse
  
• Catalog Number: LLSRK040ID
  
• Product Series: LLSRK_ID
  
• Product Family: Powr-Pro Fuse
  
• Product Type: Time-Delay Indicating Fuse
  
• Fuse Class: Class RK1
  
• Continuous Current Rating: 40 Amps
  
• Maximum AC Voltage: 600V AC
  
• Maximum DC Voltage: 300V DC
  
• Opening Characteristic: Slo-Blo / Time Lag (T) / Time Delay
  
• Indicating Feature: Yes
  
• Indicator Operation: Window Darkens When Fuse Opens
  
• Fuse Size / Style: Industrial Cartridge
  
• AC Interrupting Rating: 200,000A at 600V AC
  
• Additional Manufacturer-Published AC Interrupting Value: 300,000A at 600V AC
  
• DC Interrupting Rating: 20,000A at 300V DC
  
• Mounting Method: Fuse Block / Clip / Holder
  
• Manufacturer-Listed Holder Series: LFR60060 Series
  
• Short-Circuit Elements: Precision-Formed
  
• Overload Section: Solid-State, No Moving Parts
  

Material Compliance and Certifications

The Littelfuse LLSRK040ID is part of the Powr-Pro LLSRK_ID series, a line of Class RK1 current-limiting fuses designed to protect electrical circuits against overloads and short circuits. Its precision-formed short-circuit elements and solid-state overload section are engineered to support reliable performance in demanding electrical applications.

The manufacturer lists two AC interrupting values. Do not treat these as interchangeable certified ratings without confirming their respective test or certification basis.

Where It Works Best

• Industrial Machinery
• Motor Control Circuits
• Electrical Control Panels
• Manufacturing Equipment
• Motor-Driven Equipment
• Circuits With Temporary Startup Surges
• Industrial Electrical Distribution Systems
• Maintenance-Intensive Facilities
• Equipment Protection Applications
• Compatible Class RK1 Fuse Blocks
• Compatible Fuse Clips and Holders