LLSRK400ID - 400Amp Fuse

LLSRK400ID - 400Amp Fuse

When critical equipment suddenly stops running, the clock starts ticking. Every minute spent tracking down an electrical problem can mean lost productivity, delayed operations, and frustrated maintenance crews. That's why choosing the right fuse is about more than matching an amperage rating. You want dependable circuit protection, fewer unnecessary interruptions, and a faster way to identify problems when they happen.

The Littelfuse LLSRK400ID 400A Class RK1 time-delay indicating fuse delivers that combination. Part of the Littelfuse POWR-PRO LLSRK_ID series, this high-capacity industrial fuse protects electrical circuits against overloads and short circuits while making blown-fuse identification much easier.

Key Features and Benefits

• Built-in blown-fuse indicator
• 400-amp continuous current rating
• Class RK1 current-limiting protection
• Time-delay operation for temporary current surges
• Helps reduce nuisance fuse openings
• Precision-formed short-circuit elements
• Solid-state overload section with no moving parts
• High AC and DC interrupting ratings
• Faster identification of opened fuses
• Helps simplify electrical troubleshooting
• Knife-blade terminal configuration

Technical Specifications

• Manufacturer: Littelfuse
  
• Catalog Number: LLSRK400ID
  
• Series: LLSRK_ID
  
• Product Family: POWR-PRO Fuse
  
• Fuse Class: Class RK1
  
• Continuous Current Rating: 400A
  
• Maximum AC Voltage: 600V AC
  
• Maximum DC Voltage: 300V DC
  
• Opening Characteristic: Slo-Blo / Time Lag (T) / Time Delay
  
• Terminal Style: Knife-Blade
  
• Blown-Fuse Indication: Yes
  
• AC Interrupting Rating: 200,000A at 600V AC
  
• Additional AC Interrupting Rating: 300,000A at 600V AC, subject to applicable manufacturer rating conditions
  
• DC Interrupting Rating: 20,000A at 300V DC
  
• Mounting Method: Fuse Block / Clip / Holder
  
• Associated Holder Series: LFR60400 Series
  
• Short-Circuit Elements: Precision-Formed
  
• Overload Section: Solid-State, No Moving Parts
  
• Indicator Technology: Littelfuse Indicator™
  

Material Compliance and Certifications

The Littelfuse LLSRK400ID belongs to the POWR-PRO Class RK1 fuse family and incorporates several design features intended to support electrical protection and dependable operation.

Its construction includes precision-formed short-circuit elements, a solid-state overload section without moving parts, and Littelfuse's patented blown-fuse indicating technology.

The supplied manufacturer information confirms the fuse's electrical ratings, operating characteristics, and general construction features. However, it does not specify individual UL or CSA certification numbers, RoHS or REACH compliance declarations, or detailed material composition information.

Where It Works Best

• Industrial Motor Circuits
• Manufacturing and Production Equipment
• Industrial Control Panels
• Commercial Electrical Distribution Systems
• Heavy-Duty Industrial Machinery
• Equipment With Frequent Startup Cycles
• Maintenance-Intensive Facilities
• High-Capacity Fuse-Protected Circuits
• Compatible Fuse Blocks and Holders