BK/S501-400-R Equivalent & Substitute Parts

Part Overview

The BK/S501-400-R is a 400 mA ceramic fuse cartridge rated for 250 V AC/DC operation in a 5mm x 20mm package form factor. Manufactured by Eaton - Electronics Division, this component is classified as obsolete product status. Due to its obsolete designation, identifying equivalent and substitute parts from active product lines is necessary to maintain circuit protection functionality in ongoing production and field replacement applications. Substitute parts must maintain identical electrical ratings, mechanical dimensions, and approval certifications to ensure direct interchangeability without circuit redesign.

Substiute Parts

BK/S501-400-R

Eaton - Electronics DivisionIn Stock: 1252BK/S501-400-R Datasheet

Current PartRFQ

BK/GDA-400MA

Eaton - Electronics DivisionIn Stock: 752BK/GDA-400MA Datasheet

Parametric EquivalentRFQ

BK1/S501-400-R

Eaton - Electronics DivisionIn Stock: 1665BK1/S501-400-R Datasheet

Parametric EquivalentRFQ

GDA-400MA

Eaton - Electronics DivisionIn Stock: 1150GDA-400MA Datasheet

Parametric EquivalentRFQ

S501-400-R

Eaton - Electronics DivisionIn Stock: 1016S501-400-R Datasheet

Parametric EquivalentRFQ

5HF 400-R

Bel Fuse Inc.In Stock: 22215HF 400-R Datasheet

DirectRFQ

FCD-400MA

OptiFuseIn Stock: 5875FCD-400MA Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/S501-400-R is determined by strict equivalence across the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Current Rating: 400 mA (exact match required)
• Voltage Rating - AC: 250 V (exact match required)
• Fuse Type: Cartridge, Ceramic (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Response Time: Fast Blow (exact match required)
• Breaking Capacity @ Rated Voltage: 1.5 kA (exact match required)
• Mounting Type: Requires Holder (exact match required)

Substitute Parts Identified:

Group 1 - Eaton - Electronics Division (Same Manufacturer):

• BK/GDA-400MA (Series GDA, Active status)
• BK1/S501-400-R (Series S501, Active status)
• GDA-400MA (Series GDA, Active status)
• S501-400-R (Series S501, Active status)

Group 2 - Alternative Manufacturers:

• 5HF 400-R (Bel Fuse Inc., Series 5HF, Active status)
• FCD-400MA (OptiFuse, Series FCD, Active status)

All identified substitutes meet the primary electrical and mechanical criteria. Variations in secondary parameters (DC cold resistance, melting I²t, approval agencies, operating temperature range) are noted in the parameter comparison table but do not preclude substitution when primary criteria are satisfied.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation - Same Manufacturer Substitutes:

For applications requiring direct replacement of the obsolete BK/S501-400-R, the active-status Eaton - Electronics Division parts are preferred:

• S501-400-R (1,631 pcs inventory available) - Maintains S501 series designation with active product status and CSA/cURus certifications
• BK1/S501-400-R (1,631 pcs inventory available) - Alternative S501 series variant with ROHS3 compliance
• BK/GDA-400MA (659 pcs inventory available) - GDA series alternative with CSA/UL certifications
• GDA-400MA (1,085 pcs inventory available) - GDA series variant with CSA/UR certifications

All Eaton substitutes maintain identical electrical specifications and mechanical form factors. Selection among these options depends on certification requirements specific to the application circuit.

Alternative Manufacturer Substitutes:

• 5HF 400-R (Bel Fuse Inc., 2,206 pcs inventory) - Provides broadest certification coverage (CCC, CE, CSA, cULus) and extended operating temperature range (-55°C to 125°C). Dimensional tolerance variation noted: 0.201" diameter versus 0.205" for Eaton parts.

• FCD-400MA (OptiFuse, 5,801 pcs inventory) - Highest inventory availability. Rated for both 250 V AC and 250 V DC operation. IEC 60127 certification. Operating temperature range -55°C to 125°C.

Selection of alternative manufacturer parts is appropriate when Eaton inventory is unavailable or when specific certifications (CCC, CE, IEC 60127) are required by application standards.

Frequently Asked Questions (FAQ)

Q: Can BK/S501-400-R be directly replaced with any of the listed substitutes?

A: Yes. All listed substitute parts meet the primary electrical and mechanical criteria: 400 mA current rating, 250 V AC voltage rating, ceramic cartridge fuse type, 5mm x 20mm package, fast-blow response, 1.5 kA breaking capacity, and holder-mount configuration. Direct substitution is permissible without circuit modification.

Q: What is the difference between Eaton S501 and GDA series fuses?

A: Both series meet identical electrical specifications for this 400 mA application. The primary difference is series designation and approval agency certifications. S501 series carries CSA/cURus certifications; GDA series carries CSA/UL or CSA/UR certifications depending on variant. Selection depends on circuit certification requirements.

Q: Are there dimensional differences between substitute parts?

A: The 5HF 400-R from Bel Fuse Inc. has a nominal diameter of 0.201" (5.10mm) compared to 0.205" (5.20mm) for Eaton and OptiFuse parts. This minor variation remains within standard 5mm x 20mm cartridge fuse tolerance specifications and does not affect holder compatibility.

Q: What is the significance of DC cold resistance variations?

A: DC cold resistance values (ranging from 0.547 Ohms to 2.2 Ohms across substitutes) reflect internal element design differences but do not affect fuse operation at rated AC voltage. These variations are secondary parameters and do not preclude substitution.

Q: Which substitute has the highest inventory availability?

A: FCD-400MA from OptiFuse has 5,801 pieces in stock, the highest among all listed substitutes. This part is suitable for applications requiring immediate availability and IEC 60127 certification compliance.

Q: Do all substitutes support both AC and DC operation?

A: The main part BK/S501-400-R and most Eaton substitutes are rated for 250 V AC/DC operation. FCD-400MA explicitly specifies 250 V AC and 250 V DC ratings. 5HF 400-R specifications indicate AC/DC capability. Verify DC voltage requirements in your specific application circuit.

Q: What certifications are most commonly required?

A: CSA and UL/cULus certifications are standard for North American applications. The 5HF 400-R provides the broadest certification coverage including CCC (China), CE (Europe), CSA, and cULus. FCD-400MA provides IEC 60127 certification for international applications. Select based on target market and regulatory requirements.