GMC-300-R Equivalent & Substitute Parts

Part Overview

The GMC-300-R is a 300 mA glass cartridge fuse rated for 250 V AC/DC operation in a 5mm x 20mm form factor, manufactured by Eaton - Electronics Division. This fuse cartridge requires a compatible holder for installation and is classified as a medium blow response fuse. The part maintains Active product status with full RoHS3 compliance and multiple international approvals including CSA, KC-MARK, and UL certification. Substitute parts are identified when equivalent electrical and mechanical parameters are maintained across the same fuse category and package specification.

Substiute Parts

GMC-300-R

Eaton - Electronics DivisionIn Stock: 988GMC-300-R Datasheet

Current PartRFQ

BK/GMC-300-R

Eaton - Electronics DivisionIn Stock: 1188BK/GMC-300-R Datasheet

DirectRFQ

MSC-300MA

OptiFuseIn Stock: 1964MSC-300MA Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the GMC-300-R are classified based on strict electrical and mechanical parameter alignment. The substitution logic is structured as follows:

Direct Manufacturer Equivalent (BK/GMC-300-R): This substitute maintains identical specifications across all critical parameters including current rating (300 mA), voltage rating (250 V AC), fuse type (Cartridge, Glass), package dimensions (5mm x 20mm), response time (Medium Blow), and approval agencies (CSA, KC-MARK, UL). The part is sourced from the same manufacturer (Eaton - Electronics Division) and series (GMC), differing only in packaging designation.

Parametric Equivalent (MSC-300MA): This substitute from OptiFuse matches the core electrical parameters (300 mA current rating, 250 V AC voltage rating) and mechanical specifications (5mm x 20mm package, Cartridge Glass fuse type, Medium Blow response). The part maintains the same mounting requirement (Requires Holder) and achieves equivalent functional performance within the specified electrical envelope. Differences exist in breaking capacity (100A vs. 35A), melting I²t value (0.2167 vs. 0.081), and operating temperature range (-55°C ~ 125°C vs. unspecified), but these do not affect substitutability for applications requiring the specified current and voltage ratings.

Critical Parameters for Substitution:

• Current Rating: 300 mA (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Package / Case: 5mm x 20mm (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Medium Blow (exact match required)

Parameter Comparison

Engineering Selection Recommendations

BK/GMC-300-R Selection: This part is recommended as the primary substitute when direct manufacturer equivalence is required. Both the GMC-300-R and BK/GMC-300-R are sourced from Eaton - Electronics Division within the GMC series, maintaining identical electrical specifications, mechanical dimensions, and approval certifications (CSA, KC-MARK, UL). The parts are functionally interchangeable with no performance differentiation. Selection of BK/GMC-300-R is appropriate for applications where manufacturer consistency and series continuity are specified requirements.

MSC-300MA Selection: This part is suitable as a parametric equivalent when the core electrical and mechanical requirements (300 mA, 250 V AC, 5mm x 20mm package, Medium Blow response) are the primary selection criteria. The MSC-300MA maintains Active product status and ROHS3 compliance. The part carries cULus and UL 248 certifications, which satisfy UL-based approval requirements. The higher breaking capacity (100A) and extended operating temperature range (-55°C ~ 125°C) provide additional performance margins in applications where these characteristics are beneficial. Selection of MSC-300MA is appropriate for applications where multi-source component strategy or extended temperature operation is required.

Frequently Asked Questions (FAQ)

Q: Can BK/GMC-300-R be used as a direct replacement for GMC-300-R?

A: Yes. BK/GMC-300-R is a direct manufacturer equivalent from Eaton - Electronics Division. All electrical parameters (300 mA, 250 V AC), mechanical specifications (5mm x 20mm), fuse characteristics (Cartridge, Glass, Medium Blow), and approval certifications (CSA, KC-MARK, UL) are identical. The parts are functionally interchangeable.

Q: What are the key differences between GMC-300-R and MSC-300MA?

A: Both parts share identical core electrical specifications (300 mA, 250 V AC) and mechanical package (5mm x 20mm, Cartridge Glass, Medium Blow). Differences include: manufacturer (Eaton vs. OptiFuse), breaking capacity (35A vs. 100A), melting I²t (0.081 vs. 0.2167), approval agencies (CSA/KC-MARK/UL vs. cULus/UL 248), and operating temperature range (unspecified vs. -55°C ~ 125°C). These differences do not affect substitutability for applications requiring the specified current and voltage ratings.

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

A: Yes. All three parts (GMC-300-R, BK/GMC-300-R, and MSC-300MA) share identical mechanical dimensions (0.205" Dia x 0.787" L / 5.20mm x 20.00mm) and mounting type (Requires Holder). They are mechanically compatible with any standard 5mm x 20mm fuse holder.

Q: Which substitute should be selected for applications requiring extended temperature operation?

A: MSC-300MA specifies an operating temperature range of -55°C ~ 125°C, whereas GMC-300-R and BK/GMC-300-R do not specify operating temperature limits. For applications requiring confirmed extended temperature performance, MSC-300MA is the appropriate selection.

Q: Do all substitute parts meet the same regulatory approvals?

A: GMC-300-R and BK/GMC-300-R carry identical approvals (CSA, KC-MARK, UL). MSC-300MA carries cULus and UL 248 certifications. Both approval sets satisfy UL-based regulatory requirements, though the specific agencies differ. Application-specific regulatory requirements should be verified against the required approval standard.

Q: What is the significance of the different melting I²t values?

A: Melting I²t is a thermal characteristic that affects fuse response behavior. GMC-300-R and BK/GMC-300-R both specify 0.081, while MSC-300MA specifies 0.2167. Both values are consistent with Medium Blow response classification. The difference does not affect substitutability for applications within the specified 300 mA, 250 V AC electrical envelope.