BK/GMA-3A Equivalent & Substitute Parts Reference

Part Overview

The BK/GMA-3A is a 3 A, 250 V AC/DC fast-blow glass cartridge fuse with a 5mm x 20mm form factor manufactured by Eaton - Electronics Division. This component is classified as obsolete product status. Equivalent and substitute parts are necessary to maintain circuit protection functionality in applications where the original part is no longer available through standard distribution channels. Substitute parts must maintain electrical equivalence across current rating, voltage rating, breaking capacity, and physical dimensions while meeting applicable regulatory certifications.

Substiute Parts

BK/GMA-3A

Eaton - Electronics DivisionIn Stock: 864BK/GMA-3A Datasheet

Current PartRFQ

BK/GMA-3-R

Eaton - Electronics DivisionIn Stock: 1883BK/GMA-3-R Datasheet

DirectRFQ

GMA-3-R

Eaton - Electronics DivisionIn Stock: 4083GMA-3-R Datasheet

Parametric EquivalentRFQ

0235003.MXP

Littelfuse Inc.In Stock: 177980235003.MXP Datasheet

DirectRFQ

0235003.VXP

Littelfuse Inc.In Stock: 8120235003.VXP Datasheet

DirectRFQ

5MF 3 -R

Bel Fuse Inc.In Stock: 200325MF 3 -R Datasheet

SimilarRFQ

0034.3880

SCHURTER Inc.In Stock: 18180034.3880 Datasheet

Parametric EquivalentRFQ

0235003.HXP

Littelfuse Inc.In Stock: 15010235003.HXP Datasheet

Parametric EquivalentRFQ

FSC-3A

OptiFuseIn Stock: 805FSC-3A Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict equivalence across the following parameters: current rating (3 A), voltage rating (250 V AC), fuse type (cartridge glass), response time (fast blow), and physical package dimensions (5mm x 20mm). All substitute parts listed maintain these core electrical and mechanical specifications. Breaking capacity, melting I²t, DC cold resistance, and regulatory certifications are secondary parameters that may vary within acceptable ranges for the product category but do not disqualify substitution when primary parameters are met.

The substitute parts are grouped as follows:

Direct Manufacturer Equivalents (Eaton GMA Series): Parts BK/GMA-3-R and GMA-3-R represent the active production equivalents to the obsolete BK/GMA-3A, with identical electrical specifications and form factor.

Cross-Manufacturer Parametric Equivalents (Littelfuse 235 Series): Parts 0235003.MXP, 0235003.VXP, and 0235003.HXP maintain all primary electrical and mechanical parameters with enhanced regulatory certifications and improved RoHS compliance status.

Cross-Manufacturer Parametric Equivalents (SCHURTER FSK Series): Part 0034.3880 meets all primary substitution criteria with identical current, voltage, and package specifications.

Cross-Manufacturer Similar Parts (Bel Fuse 5MF Series): Part 5MF 3 -R maintains primary electrical specifications with higher breaking capacity (200 A) and melting I²t (13) but with minor dimensional variation (5.10mm diameter vs. 5.20mm).

Cross-Manufacturer Parametric Equivalents (OptiFuse FSC Series): Part FSC-3A meets all primary electrical and mechanical parameters with active product status and current certifications.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: BK/GMA-3-R or GMA-3-R (Eaton - Electronics Division). These parts are direct manufacturer equivalents with identical electrical specifications, form factor, and breaking capacity to the obsolete BK/GMA-3A. Both are active production parts with current RoHS compliance certifications (ROHS3 Compliant). BK/GMA-3-R is available in bulk packaging with 1832 units in stock; GMA-3-R is available with 4069 units in stock. Selection between these two Eaton variants depends on packaging requirements and inventory availability.

Secondary Recommendation: 0235003.MXP or 0235003.VXP (Littelfuse Inc., 235 Series). These parts maintain all primary electrical and mechanical parameters with active product status and ROHS3 compliance. Littelfuse parts feature enhanced regulatory certifications (CE, CSA, KC, PSE, UL) and extended operating temperature range (-55°C to 125°C). Melting I²t is slightly lower (8.395 vs. 8.8) and DC cold resistance is lower (0.0347 vs. 0.039 Ohms), representing minor performance variations within acceptable substitution tolerance. 0235003.MXP has 17759 units in stock; 0235003.VXP has 763 units in stock.

Tertiary Recommendation: 0034.3880 (SCHURTER Inc., FSK 5x20 Series). This part meets all primary substitution criteria with identical current rating, voltage rating, package dimensions, and breaking capacity. ROHS3 compliant with active product status. Melting I²t is lower (6.8 vs. 8.8), indicating faster thermal response. Operating temperature range is narrower (-40°C to 85°C). 1709 units in stock.

Alternative Consideration: 5MF 3 -R (Bel Fuse Inc., 5MF Series). This part maintains primary electrical specifications with higher breaking capacity (200 A vs. 100 A) and higher melting I²t (13 vs. 8.8), providing enhanced fault protection capability. Minor dimensional variation exists (5.10mm diameter vs. 5.20mm), which may require verification for mechanical fit in existing fuse holders. ROHS3 compliant with active product status. 20016 units in stock.

Alternative Consideration: FSC-3A (OptiFuse, FSC Series). This part meets all primary electrical and mechanical parameters with active product status and current certifications (cULus, UL 248). ROHS3 compliant. Operating temperature range is -55°C to 90°C. 781 units in stock.

Frequently Asked Questions (FAQ)

Q: What are the critical parameters that determine if a part can substitute for BK/GMA-3A?

A: The critical parameters are: current rating (3 A), voltage rating (250 V AC), fuse type (cartridge glass), response time (fast blow), and physical package dimensions (5mm x 20mm). All listed substitute parts maintain these specifications. Secondary parameters such as breaking capacity, melting I²t, and DC cold resistance may vary within acceptable ranges for the product category.

Q: Why is BK/GMA-3A listed as obsolete?

A: BK/GMA-3A is classified as obsolete product status, meaning it is no longer in active production by Eaton - Electronics Division. Direct manufacturer equivalents BK/GMA-3-R and GMA-3-R are the active production replacements with identical electrical and mechanical specifications.

Q: Can I use 5MF 3 -R as a direct substitute despite the dimensional difference?

A: 5MF 3 -R maintains all primary electrical specifications (3 A, 250 V, fast blow, 5mm x 20mm package). The diameter is 5.10mm versus 5.20mm for the original part. Mechanical fit in the existing fuse holder must be verified before installation. The higher breaking capacity (200 A) and melting I²t (13) provide enhanced fault protection.

Q: What is the difference between BK/GMA-3-R and GMA-3-R?

A: Both parts are Eaton - Electronics Division equivalents with identical electrical specifications and form factor. BK/GMA-3-R is available in bulk packaging with 1832 units in stock and ROHS3 compliance. GMA-3-R has 4069 units in stock and RoHS compliance. Selection depends on packaging requirements and inventory availability.

Q: Are all substitute parts RoHS compliant?

A: All substitute parts listed are RoHS compliant (ROHS3 Compliant or RoHS Compliant). The original BK/GMA-3A is RoHS non-compliant. This represents an improvement in environmental and regulatory compliance when substituting to any of the listed alternatives.

Q: What regulatory certifications should I verify for my application?

A: The original BK/GMA-3A carries CCC, CSA, MITI, and UL certifications. Substitute parts carry varying certification sets: Eaton parts (CSA, PSE, UL or CSA, UL), Littelfuse parts (CE, CSA, KC, PSE, UL), SCHURTER part (cULus), Bel Fuse part (CE, CSA, cULus, PSE), and OptiFuse part (cULus, UL 248). Verify that the substitute part's certifications meet your application requirements.

Q: How do melting I²t values affect substitution?

A: Melting I²t indicates the thermal energy required to melt the fuse element. The original BK/GMA-3A has melting I²t of 8.8. Substitute parts range from 6.8 to 13. Lower values indicate faster thermal response; higher values indicate slower response. All listed parts are within acceptable substitution tolerance for the 3 A, 250 V category.

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

A: DC cold resistance affects voltage drop across the fuse during normal operation. The original BK/GMA-3A has 0.039 Ohms. Littelfuse parts have 0.0347 Ohms (lower), Bel Fuse has 0.03 Ohms (lower), and OptiFuse has 9.722 Ohms (significantly higher). Lower resistance values result in minimal voltage drop; the OptiFuse part should be evaluated for voltage drop impact in sensitive applications.

Q: Can I mix different substitute parts in the same circuit?

A: All listed substitute parts maintain identical current rating (3 A) and voltage rating (250 V). However, mixing parts with different melting I²t values or breaking capacities in the same circuit may result in inconsistent fault protection response. Use a single part number throughout a circuit for consistent protection characteristics.

Q: What is the operating temperature range for each substitute?

A: Operating temperature ranges vary: BK/GMA-3A and Eaton equivalents are not specified; Littelfuse parts are -55°C to 125°C; Bel Fuse is -55°C to 125°C; SCHURTER is -40°C to 85°C; OptiFuse is -55°C to 90°C. Verify that the selected substitute meets your application's temperature requirements.