LH251003C Equivalent & Substitute Parts

Part Overview

The LH251003C is a fuse block cartridge designed for 250V, 100A applications with 3-circuit configuration and chassis mount orientation. This component is classified as obsolete, making identification of suitable alternatives essential for ongoing system maintenance and new design implementations. The obsolete status necessitates evaluation of active product alternatives that maintain functional and electrical compatibility.

Substiute Parts

LH251003C

Littelfuse Inc.In Stock: 923LH251003C Datasheet

Current PartRFQ

LFH251003CID

Littelfuse Inc.In Stock: 908LFH251003CID Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LH251003C is determined by the following critical parameters that must remain constant across alternatives:

• Voltage Rating: 250V (non-negotiable for safety and system compatibility)
• Current Rating: 100 A (electrical performance requirement)
• Number of Circuits: 3 (functional configuration)
• Fuse Type: Cartridge (mechanical and electrical interface)
• Fuseholder Type: Block (form factor and installation method)
• Termination Style: Box Lug (electrical connection interface)
• Fuse Compatibility: Class H(K), Class R Fuses (operational specification)

The LFH251003CID qualifies as a direct substitute based on matching all critical electrical and functional parameters. The primary difference is the mounting configuration: the substitute transitions from chassis mount to DIN rail mount, which represents a mechanical accommodation rather than an electrical incompatibility. Both parts maintain identical voltage, current, circuit count, fuse type, and termination characteristics.

Parameter Comparison

Engineering Selection Recommendations

The LFH251003CID is the direct electrical and functional equivalent to the LH251003C. Selection between these parts is determined by installation environment and regulatory requirements:

LFH251003CID is the preferred choice when:

• New installations or system redesigns are planned
• DIN rail mounting infrastructure is available or can be implemented
• ROHS3 compliance is required for the application
• Active product support and availability are priorities

LH251003C remains applicable only for:

• Existing systems requiring exact form-factor replacement in chassis mount configurations
• Legacy equipment where mounting modification is not feasible
• Applications where RoHS non-compliance is acceptable

The transition from chassis mount to DIN rail represents a mechanical accommodation that does not affect electrical performance, fuse compatibility, or circuit functionality. Both configurations maintain identical voltage, current, and circuit specifications.

Frequently Asked Questions (FAQ)

Q: Can LFH251003CID directly replace LH251003C in existing installations?

A: Electrical compatibility is complete. Mechanical compatibility depends on the mounting infrastructure. If the original system uses chassis mount hardware, the DIN rail mount of LFH251003CID requires installation method modification. The electrical performance and fuse block functionality remain identical.

Q: What are the key differences between these two parts?

A: The primary differences are mounting type (chassis mount versus DIN rail) and product status (obsolete versus active). Electrical specifications, voltage rating, current capacity, circuit count, fuse type, and termination style are identical. RoHS compliance status also differs, with LFH251003CID meeting ROHS3 requirements.

Q: Are there any fuse compatibility differences?

A: No. Both the LH251003C and LFH251003CID are designed for use with Class H(K) and Class R cartridge fuses. Fuse selection and performance are not affected by the choice between these two fuseholder blocks.

Q: Why is the LH251003C listed as obsolete?

A: Product obsolescence typically reflects manufacturer discontinuation decisions. The LFH251003CID represents the active product line continuation from Littelfuse Inc., offering the same electrical functionality with updated mounting standards and regulatory compliance.

Q: Can I use this substitute in a new design?

A: Yes. The LFH251003CID is the recommended choice for new designs. It provides active product support, ROHS3 compliance, and DIN rail mounting, which aligns with current industrial standards for fuse block installation.

Q: What is the inventory status for these parts?

A: LH251003C has 820 pieces available as new original stock. LFH251003CID has 831 pieces available as new original stock. Both are currently in inventory.