BK/S501-125-R Equivalent & Substitute Parts

Part Overview

The BK/S501-125-R is a ceramic cartridge fuse manufactured by Eaton - Electronics Division, rated for 125 mA at 250 V AC/DC. This fast-blow fuse is designed for 5mm x 20mm holder applications and requires an external fuse holder for installation. The part is currently active in production with 1057 units in stock. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and supply chain continuity when the primary part becomes unavailable or when alternative sourcing is required.

Substiute Parts

BK/S501-125-R

Eaton - Electronics DivisionIn Stock: 1156BK/S501-125-R Datasheet

Current PartRFQ

GDA-125MA

Eaton - Electronics DivisionIn Stock: 827GDA-125MA Datasheet

Parametric EquivalentRFQ

0216.125HXP

Littelfuse Inc.In Stock: 12320216.125HXP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the BK/S501-125-R is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Current Rating: 125 mA
• Voltage Rating (AC): 250 V
• Fuse Type: Cartridge, Ceramic
• Package / Case: 5mm x 20mm
• Response Time: Fast Blow
• Breaking Capacity @ Rated Voltage: 1.5 kA
• Mounting Type: Requires Holder

Both identified substitute parts—GDA-125MA (Eaton - Electronics Division) and 0216.125HXP (Littelfuse Inc.)—meet all mandatory matching parameters and are therefore classified as parametric equivalents. These parts are electrically and mechanically interchangeable within applications designed for the BK/S501-125-R.

Parameter Comparison

Engineering Selection Recommendations

BK/S501-125-R (Primary Part): Manufactured by Eaton - Electronics Division with CSA and cULus certifications. ROHS3 compliant. Recommended for applications requiring Eaton-sourced components or where cULus certification is specifically mandated. Current inventory of 1057 units supports immediate availability.

GDA-125MA (Eaton Equivalent): Manufactured by Eaton - Electronics Division with CSA and UR certifications. Provides direct manufacturer equivalence to the BK/S501-125-R within the Eaton product portfolio. Suitable for applications where Eaton sourcing is required but cULus certification is not mandatory. Inventory of 720 units available.

0216.125HXP (Littelfuse Equivalent): Manufactured by Littelfuse Inc. with the broadest certification scope: CCC, CE, CSA, SEMKO, UL, and VDE. ROHS3 compliant with specified operating temperature range of -55°C to 125°C. Recommended for applications requiring multi-regional compliance or extended temperature operation. Highest inventory availability at 1175 units. Note: DC cold resistance (3.675 Ohms) and melting I²t (0.00546) differ from the primary part; verify compatibility with circuit-specific requirements.

All three parts are active products with established supply chains and meet the core electrical and mechanical requirements for 125 mA, 250 V AC/DC ceramic cartridge fuse applications in 5mm x 20mm holders.

Frequently Asked Questions (FAQ)

Q: Can GDA-125MA be used as a direct replacement for BK/S501-125-R?

A: Yes. Both parts are manufactured by Eaton - Electronics Division and share identical electrical ratings (125 mA, 250 V AC/DC), fuse type (ceramic cartridge), package dimensions (5mm x 20mm), response time (fast blow), and breaking capacity (1.5 kA). Both require external fuse holders. Certification differences (cULus vs. UR) should be verified against application requirements.

Q: What are the differences between 0216.125HXP and the Eaton parts?

A: The 0216.125HXP is manufactured by Littelfuse Inc. and shares all critical electrical and mechanical parameters with the Eaton parts. Key differences include: broader certification scope (CCC, CE, CSA, SEMKO, UL, VDE vs. CSA/cULus or CSA/UR), specified operating temperature range (-55°C to 125°C), lower DC cold resistance (3.675 Ohms vs. 12.3 Ohms), and higher melting I²t (0.00546 vs. 0.0037). These differences do not affect basic interchangeability but should be evaluated for specific circuit applications.

Q: Are all three parts compatible with the same fuse holder?

A: Yes. All three parts conform to the 5mm x 20mm package standard and require external fuse holders designed for this form factor. Physical dimensions are identical: 0.205" diameter x 0.787" length.

Q: Which part should I select for international applications?

A: The 0216.125HXP offers the broadest international certification coverage (CCC, CE, CSA, SEMKO, UL, VDE) and is suitable for multi-regional deployment. The Eaton parts (BK/S501-125-R and GDA-125MA) carry CSA certification and are appropriate for North American applications.

Q: Does the difference in DC cold resistance affect substitution?

A: DC cold resistance differences (12.3 Ohms for Eaton parts vs. 3.675 Ohms for Littelfuse) reflect manufacturing variations but do not prevent substitution in standard fuse applications. However, circuits with specific impedance or voltage drop requirements should verify compatibility with the selected part's resistance value.

Q: Are all parts RoHS compliant?

A: BK/S501-125-R and 0216.125HXP are explicitly ROHS3 compliant. GDA-125MA RoHS status is not specified in available documentation; verify with Eaton if RoHS compliance is a requirement.