Littelfuse 0672001.DRT4 Equivalent & Substitute Parts

Part Overview

The Littelfuse 0672001.DRT4 is a 1 A, 250 V AC/DC fast-blow glass cartridge fuse with axial through-hole mounting. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing system maintenance. The glass cartridge construction provides visual indication of fuse status and is widely used in industrial and consumer electronics applications requiring reliable overcurrent protection.

Substiute Parts

0672001.DRT4

Littelfuse Inc.In Stock: 8380672001.DRT4 Datasheet

Current PartRFQ

0874001.MRET1P

Littelfuse Inc.In Stock: 7860874001.MRET1P Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 0672001.DRT4 is based on the following critical electrical and mechanical parameters:

• Current Rating: 1 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Cartridge, Non-Standard (Axial) (exact match required)

The primary substitute, Littelfuse 0874001.MRET1P, meets all critical electrical parameters. The key difference is the cartridge material: the substitute uses ceramic construction instead of glass. Both materials provide equivalent electrical performance and safety characteristics for this application class. The ceramic variant offers improved thermal stability and RoHS3 compliance, making it suitable for modern manufacturing environments.

Parameter Comparison

Engineering Selection Recommendations

The Littelfuse 0874001.MRET1P is the direct electrical equivalent for the obsolete 0672001.DRT4. Selection should be based on the following factors:

Product Status: The main part is obsolete; the substitute is active and currently manufactured, ensuring long-term availability and supply chain continuity.

Compliance & Certifications: The substitute holds cULus certification and is ROHS3 compliant, meeting modern regulatory requirements. The original part carries CSA and UL approvals but is non-compliant with current RoHS standards.

Thermal Performance: The substitute specifies an operating temperature range of -55°C to 125°C, providing defined thermal boundaries for system design. The original part does not specify operating temperature limits.

Physical Dimensions: The substitute is slightly smaller (0.142" Dia x 0.394" L versus 0.154" Dia x 0.433" L). Verify mechanical fit in existing fuse holders or sockets before implementation.

Electrical Characteristics: Both parts deliver identical current and voltage ratings with matching breaking capacity. The ceramic substitute exhibits lower DC cold resistance (0.086 Ohms versus 0.1056 Ohms) and lower melting I²t (0.406 versus 0.508), indicating slightly faster response characteristics within the fast-blow classification.

Frequently Asked Questions (FAQ)

Q: Can the 0874001.MRET1P directly replace the 0672001.DRT4 in existing designs?

A: Yes, from an electrical standpoint. Both parts are 1 A, 250 V AC/DC fast-blow fuses with identical breaking capacity and mounting type. Verify that the slightly smaller physical dimensions of the ceramic substitute fit within your existing fuse holder or socket. The ceramic cartridge material is functionally equivalent to glass for overcurrent protection applications.

Q: What is the primary difference between these two fuses?

A: The main difference is cartridge material: the original uses glass construction, while the substitute uses ceramic. Both provide equivalent electrical performance and safety. The ceramic variant offers improved thermal stability, defined operating temperature range, and modern RoHS3 compliance.

Q: Why is the original part obsolete?

A: The 0672001.DRT4 is classified as obsolete by the manufacturer. The 0874001.MRET1P represents the current active product line for this electrical specification, ensuring ongoing availability and support.

Q: Are there any compatibility concerns with the physical size difference?

A: The substitute is slightly smaller in both diameter and length. Ensure your fuse holder or socket can accommodate the 0.142" Dia x 0.394" L dimensions. If the original holder was designed with tight tolerances for the 0.154" Dia x 0.433" L size, mechanical fit must be verified before deployment.

Q: Do both fuses carry the same safety certifications?

A: Both carry recognized safety certifications. The original holds CSA and UL approvals; the substitute holds cULus certification. The substitute additionally meets ROHS3 compliance, which is required for many modern applications and supply chains.

Q: What does the lower melting I²t value of the substitute mean?

A: The substitute's lower melting I²t (0.406 versus 0.508) indicates it will respond slightly faster to overcurrent conditions while remaining within the fast-blow classification. Both parts meet the same current and voltage ratings and breaking capacity, so this difference is within acceptable performance parameters for this fuse category.