5MF 1.5 Equivalent & Substitute Parts

Part Overview

The 5MF 1.5 is a fast-blow glass cartridge fuse rated at 1.5 A, 250 V AC/DC, with a 5mm x 20mm form factor. This component is classified as obsolete, which necessitates identification of active equivalent parts for continued system support and procurement. The substitute part maintains identical electrical and mechanical specifications while offering improved compliance status and current inventory availability.

Substiute Parts

5MF 1.5

Bel Fuse Inc.In Stock: 8345MF 1.5 Datasheet

Current PartRFQ

5MF 1.5-R

Bel Fuse Inc.In Stock: 29115MF 1.5-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 5MF 1.5-R qualifies as a direct substitute for the 5MF 1.5 based on the following critical parameters:

• Current Rating: Identical at 1.5 A
• Voltage Rating (AC): Identical at 250 V
• Fuse Type: Identical cartridge glass construction
• Response Time: Identical fast-blow characteristic
• Package / Case: Identical 5mm x 20mm form factor
• Breaking Capacity: Identical at 200 A
• Operating Temperature Range: Identical -55°C ~ 125°C
• Mounting Type: Identical holder requirement

The substitute part is manufactured by the same supplier (Bel Fuse Inc.) and maintains full electrical and mechanical compatibility with the original design.

Parameter Comparison

Engineering Selection Recommendations

The 5MF 1.5-R is the direct replacement for the obsolete 5MF 1.5. Selection of the active substitute is based on:

• Product Status: The 5MF 1.5-R maintains active production status, ensuring long-term availability and supply chain continuity.
• Regulatory Compliance: The 5MF 1.5-R achieves ROHS3 compliance, whereas the original part is non-compliant. This addresses modern environmental and regulatory requirements.
• Certification Scope: Both parts carry CE, CSA, and PSE certifications. The 5MF 1.5-R includes cULus certification, providing expanded North American market coverage.
• Electrical Equivalence: All critical electrical parameters—current rating, voltage rating, breaking capacity, and response time—are identical between the two parts.
• Mechanical Compatibility: The 5mm x 20mm form factor and holder requirement remain unchanged, ensuring direct mechanical interchangeability.

Frequently Asked Questions (FAQ)

Q: Can the 5MF 1.5-R be used as a direct replacement for the 5MF 1.5?

A: Yes. The 5MF 1.5-R is electrically and mechanically identical to the 5MF 1.5. Both parts share the same current rating (1.5 A), voltage rating (250 V AC), response time (fast-blow), and 5mm x 20mm form factor. No circuit modifications are required.

Q: What is the difference in melting I²t between the two parts?

A: The melting I²t values are 2.58 for the 5MF 1.5 and 2.6 for the 5MF 1.5-R. This minor variation (0.02) falls within normal manufacturing tolerance and does not affect functional equivalence or circuit protection characteristics.

Q: Does the 5MF 1.5-R require a different holder than the 5MF 1.5?

A: No. Both parts require the same holder type for the 5mm x 20mm cartridge fuse form factor. Existing fuse holders are compatible with the substitute part.

Q: What are the compliance advantages of the 5MF 1.5-R?

A: The 5MF 1.5-R is ROHS3 compliant, whereas the original 5MF 1.5 is non-compliant. The substitute also carries cULus certification in addition to CE, CSA, and PSE certifications, providing broader regulatory acceptance.

Q: Is there any difference in operating temperature range?

A: No. Both the 5MF 1.5 and 5MF 1.5-R operate across the identical temperature range of -55°C to 125°C.

Q: What is the difference in DC cold resistance?

A: The 5MF 1.5 has a DC cold resistance of 0.07 Ohms, while the 5MF 1.5-R measures 0.067 Ohms. This negligible difference (0.003 Ohms) is within acceptable tolerance and does not impact circuit performance.