BK/GMC-400MA Equivalent & Substitute Parts

Part Overview

The BK/GMC-400MA is a 400 mA, 250 V AC/DC glass cartridge fuse manufactured by Eaton - Electronics Division in a 5mm x 20mm form factor. This fuse is classified as obsolete product status, requiring identification of active equivalent alternatives for ongoing procurement and system maintenance. The medium blow response time and 35A breaking capacity at rated voltage establish the electrical performance baseline for substitute selection.

Substiute Parts

BK/GMC-400MA

Eaton - Electronics DivisionIn Stock: 994BK/GMC-400MA Datasheet

Current PartRFQ

BK/GMC-400-R

Eaton - Electronics DivisionIn Stock: 1857BK/GMC-400-R Datasheet

DirectRFQ

BK1/GMC-400-R

Eaton - Electronics DivisionIn Stock: 1139BK1/GMC-400-R Datasheet

Parametric EquivalentRFQ

GMC-400-R

Eaton - Electronics DivisionIn Stock: 809GMC-400-R Datasheet

Parametric EquivalentRFQ

0034.2512

SCHURTER Inc.In Stock: 18950034.2512 Datasheet

Parametric EquivalentRFQ

20104000001P

Littelfuse Inc.In Stock: 69820104000001P Datasheet

Parametric EquivalentRFQ

20104000021P

Littelfuse Inc.In Stock: 75220104000021P Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BK/GMC-400MA are grouped into two categories based on electrical and mechanical parameter alignment:

Direct Manufacturer Equivalents (Eaton GMC Series): BK/GMC-400-R, BK1/GMC-400-R, and GMC-400-R maintain identical electrical specifications (400 mA, 250 V AC, 0.615 Ohms DC cold resistance, 0.18 Melting I²t) and mechanical form factor (5mm x 20mm). These parts differ only in product status (active versus obsolete) and RoHS compliance level. All three are manufactured by Eaton - Electronics Division within the GMC series.

Cross-Manufacturer Parametric Equivalents: 0034.2512 (SCHURTER Inc., FSM 5x20 series), 20104000001P, and 20104000021P (Littelfuse Inc., 201P series) share the core electrical parameters (400 mA current rating, 250 V AC voltage rating, 5mm x 20mm package, medium blow response) but exhibit variations in secondary parameters. The SCHURTER part specifies 125 V DC rating and 80A breaking capacity with 0.632 Melting I²t. The Littelfuse parts specify 80A breaking capacity with 0.28 Melting I²t. These differences reflect manufacturer-specific design approaches within the same functional category.

Substitution eligibility is determined by matching: current rating (400 mA), AC voltage rating (250 V), fuse type (cartridge glass), package dimensions (5mm x 20mm), response time (medium blow), and mounting requirement (requires holder).

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation - Eaton GMC Series Direct Equivalents:

BK/GMC-400-R, BK1/GMC-400-R, and GMC-400-R are direct functional replacements for the obsolete BK/GMC-400MA. These parts maintain identical electrical performance (400 mA, 250 V AC, 0.18 Melting I²t, 0.615 Ohms DC cold resistance) and mechanical compatibility (5mm x 20mm cartridge form factor). All three are active products with ROHS3 compliance, eliminating the regulatory risk associated with the non-compliant original part. Selection among these three Eaton variants depends on packaging requirements and internal part numbering conventions within procurement systems.

Secondary Recommendation - Cross-Manufacturer Alternatives:

The SCHURTER 0034.2512 and Littelfuse 20104000001P/20104000021P parts satisfy the core electrical and mechanical substitution criteria (400 mA, 250 V AC, 5mm x 20mm, medium blow response). These alternatives are appropriate when Eaton GMC series availability is constrained or when supply chain diversification is required. The SCHURTER part includes explicit 125 V DC rating and higher breaking capacity (80A), providing enhanced performance margin in DC applications. The Littelfuse parts offer equivalent AC performance with higher breaking capacity (80A) and different thermal characteristics (0.28 Melting I²t).

Compliance Consideration:

All recommended substitute parts carry ROHS3 compliance certification, addressing the non-compliance status of the original BK/GMC-400MA. Approval agencies vary across manufacturers (CSA/KC-MARK/UL for Eaton; cULus for Littelfuse), reflecting regional certification requirements.

Frequently Asked Questions (FAQ)

Q: Can BK/GMC-400-R directly replace BK/GMC-400MA in existing designs?

A: Yes. BK/GMC-400-R is a direct equivalent with identical electrical specifications (400 mA, 250 V AC, 0.18 Melting I²t, 0.615 Ohms DC cold resistance) and mechanical form factor (5mm x 20mm cartridge). The primary difference is product status (active versus obsolete) and RoHS compliance improvement.

Q: What is the difference between BK/GMC-400-R, BK1/GMC-400-R, and GMC-400-R?

A: All three parts are manufactured by Eaton within the GMC series and share identical electrical and mechanical specifications. Differences are limited to part number designation and internal manufacturer coding. Selection should be based on procurement system requirements and inventory availability.

Q: Can SCHURTER 0034.2512 replace the Eaton GMC-400MA?

A: Yes, with parameter awareness. The SCHURTER part matches the core substitution criteria (400 mA, 250 V AC, 5mm x 20mm, medium blow). However, it specifies additional 125 V DC rating and higher breaking capacity (80A versus 35A) and different Melting I²t (0.632 versus 0.18). These differences indicate enhanced performance characteristics suitable for applications requiring higher fault current handling.

Q: Are Littelfuse 20104000001P and 20104000021P interchangeable?

A: Yes. Both parts are from the Littelfuse 201P series with identical electrical specifications (400 mA, 250 V AC, 80A breaking capacity, 0.28 Melting I²t) and mechanical form factor (5mm x 20mm). Differences in part number designation reflect internal Littelfuse coding; electrical and mechanical performance are equivalent.

Q: What does "Requires Holder" mean for mounting type?

A: All listed parts are cartridge fuses that require a separate fuse holder for installation. The fuse itself is not self-contained; it must be inserted into a compatible 5mm x 20mm fuse holder assembly. Verify that existing fuse holder hardware is compatible with the selected substitute part.

Q: How do Melting I²t values affect substitution?

A: Melting I²t is a thermal energy parameter that characterizes fuse response speed. The original BK/GMC-400MA specifies 0.18, while cross-manufacturer alternatives range from 0.28 to 0.632. Higher Melting I²t values indicate slower thermal response. Substitution is valid when the application circuit design accommodates the thermal characteristics of the selected alternative. Verify circuit protection requirements before selecting parts with significantly different Melting I²t values.

Q: What is the significance of breaking capacity differences?

A: Breaking capacity (35A for Eaton GMC series, 80A for SCHURTER and Littelfuse) defines the maximum fault current the fuse can safely interrupt. Higher breaking capacity provides greater safety margin in high-fault-current applications. The original BK/GMC-400MA specifies 35A; substitutes with 80A breaking capacity offer enhanced fault protection capability without compromising normal-operation performance.

Q: Are all substitute parts RoHS compliant?

A: Yes. All active substitute parts (BK/GMC-400-R, BK1/GMC-400-R, GMC-400-R, 0034.2512, 20104000001P, 20104000021P) carry ROHS3 compliance certification. The original BK/GMC-400MA is RoHS non-compliant, making substitution necessary for regulatory compliance in new designs and updated systems.