BK1/GMA-3.5-R Equivalent & Substitute Parts

Part Overview

The BK1/GMA-3.5-R is a 3.5 A, 125 V AC/DC fast-blow glass cartridge fuse manufactured by Eaton - Electronics Division. This component is designed for circuit protection in applications requiring a 5mm x 20mm form factor and operates within the GMA series specifications. The part maintains Active product status with 1278 units in current inventory stock.

Identification of equivalent and substitute parts becomes necessary when the primary part experiences supply constraints, when application requirements demand higher voltage ratings, or when design specifications allow for compatible alternatives that meet or exceed the original performance parameters.

Substiute Parts

BK1/GMA-3.5-R

Eaton - Electronics DivisionIn Stock: 1342BK1/GMA-3.5-R Datasheet

Current PartRFQ

023503.5MXP

Littelfuse Inc.In Stock: 3383023503.5MXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BK1/GMA-3.5-R is determined by the following critical parameters:

Mandatory Compatibility Parameters:

• Current Rating: 3.5 A (must match exactly)
• Fuse Type: Cartridge, Glass (must match exactly)
• Response Time: Fast Blow (must match exactly)
• Package / Case: 5mm x 20mm (must match exactly)
• Mounting Type: Requires Holder (must match exactly)

Allowable Variation Parameters:

• Voltage Rating - AC: The substitute may exceed the original rating (125 V minimum required)
• Breaking Capacity: The substitute may exceed the original rating (10 kA minimum required)
• Melting I²t: The substitute may exceed the original rating (13 minimum required)
• DC Cold Resistance: Minor variations acceptable within engineering tolerance
• Approval Agencies: Substitute must maintain equivalent or superior certifications

The Littelfuse 023503.5MXP qualifies as a direct substitute because it maintains identical current rating, fuse type, response time, and physical dimensions while providing enhanced voltage rating (250 V), superior breaking capacity (100 A), and equivalent regulatory compliance.

Parameter Comparison

Engineering Selection Recommendations

Primary Part Selection: The BK1/GMA-3.5-R remains the preferred choice for applications specifically designed for 125 V AC operation with established supply availability (1278 units in stock) and full compliance with CSA, PSE, and UL certifications.

Substitute Part Selection: The Littelfuse 023503.5MXP is suitable for applications where:

• The circuit design permits operation at 250 V AC rating
• Enhanced breaking capacity (100 A versus 10 kA) is acceptable or beneficial
• Higher melting I²t value (17.14 versus 13) aligns with circuit protection requirements
• Operating temperature range of -55°C to 125°C meets environmental specifications
• CE, PSE, and UL certifications satisfy regulatory requirements

Both parts maintain identical physical dimensions, current ratings, and fast-blow response characteristics, ensuring mechanical and electrical compatibility within fuse holder assemblies designed for the 5mm x 20mm form factor.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 023503.5MXP be used in place of the BK1/GMA-3.5-R?

A: Yes. The 023503.5MXP maintains the same current rating (3.5 A), fuse type (cartridge glass), response time (fast blow), and physical dimensions (5mm x 20mm). The higher voltage rating (250 V versus 125 V) and enhanced breaking capacity represent improved performance characteristics suitable for the same mechanical installation.

Q: What is the significance of the voltage rating difference?

A: The voltage rating indicates the maximum voltage at which the fuse is designed to safely interrupt a circuit. The 023503.5MXP's 250 V rating provides compatibility with both 125 V and 250 V applications, whereas the BK1/GMA-3.5-R is limited to 125 V circuits. Selection depends on the actual circuit voltage requirement.

Q: Are there differences in physical dimensions between these parts?

A: No. Both parts share identical physical dimensions of 5.20mm diameter by 20.00mm length (0.205" Dia x 0.787" L), ensuring compatibility with standard 5mm x 20mm fuse holders.

Q: How do the melting I²t values affect substitution?

A: The melting I²t value (13 for BK1/GMA-3.5-R and 17.14 for 023503.5MXP) represents the thermal energy required to melt the fuse element. The higher value in the substitute indicates slightly different thermal characteristics but maintains the same 3.5 A current rating and fast-blow response classification.

Q: What certifications apply to both parts?

A: Both parts hold UL and PSE certifications. The BK1/GMA-3.5-R additionally carries CSA certification, while the 023503.5MXP carries CE certification. All certifications confirm compliance with applicable safety standards for circuit protection devices.

Q: Is the DC cold resistance difference significant?

A: The DC cold resistance values (0.03 Ohms for BK1/GMA-3.5-R and 0.0331 Ohms for 023503.5MXP) represent minimal variation within normal manufacturing tolerances and do not affect substitution suitability for standard circuit protection applications.