GMC-300MA Equivalent & Substitute Parts

Part Overview

The GMC-300MA 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 operates with a medium blow response time. The part is actively stocked with 880 pieces in inventory. Equivalent and substitute parts are identified based on matching electrical ratings, mechanical dimensions, and functional specifications to ensure direct interchangeability in circuit protection applications.

Substiute Parts

GMC-300MA

Eaton - Electronics DivisionIn Stock: 906GMC-300MA Datasheet

Current PartRFQ

GMC-300-R

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

DirectRFQ

BK/GMC-300-R

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

Parametric EquivalentRFQ

BK1/GMC-300-R

Eaton - Electronics DivisionIn Stock: 829BK1/GMC-300-R Datasheet

Parametric EquivalentRFQ

MSC-300MA

OptiFuseIn Stock: 1964MSC-300MA Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the GMC-300MA is determined by strict equivalence across the following parameters:

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

All substitute parts listed below meet these criteria and are therefore electrically and mechanically interchangeable with the GMC-300MA in applications requiring a 300 mA, 250 V AC/DC glass cartridge fuse in a 5x20mm package.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts are active products with current manufacturing status. Selection among equivalent parts may be based on the following factors:

Eaton - Electronics Division variants (GMC-300MA, GMC-300-R, BK/GMC-300-R, BK1/GMC-300-R) are approved by CSA, KC-MARK, and UL certification agencies. These parts share identical electrical and mechanical specifications with DC cold resistance of 0.838 Ohms and breaking capacity of 35A at rated voltage.

OptiFuse MSC-300MA is approved by cULus and UL 248 certification agencies. This part meets the same electrical and mechanical requirements as the Eaton variants. The MSC-300MA has a higher breaking capacity of 100A at rated voltage and an extended operating temperature range of -55°C to 125°C compared to the Eaton variants.

All parts are RoHS3 compliant and carry EAR99 export classification. Selection should be based on application-specific requirements including breaking capacity, operating temperature range, and certification requirements.

Frequently Asked Questions (FAQ)

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

A: Yes. GMC-300-R is a direct substitute for GMC-300MA. Both parts share identical current rating (300 mA), voltage rating (250 V AC), fuse type (cartridge, glass), package dimensions (5mm x 20mm), and response time (medium blow). Both require a compatible fuse holder for installation.

Q: What is the difference between BK/GMC-300-R and BK1/GMC-300-R?

A: Both BK/GMC-300-R and BK1/GMC-300-R are electrically and mechanically equivalent to GMC-300MA. The primary difference is in certification agency approval: BK/GMC-300-R is approved by CSA, KC-MARK, and UL, while BK1/GMC-300-R is approved by CSA, KC, and UL. Both parts have identical electrical specifications and package dimensions.

Q: Is MSC-300MA from OptiFuse compatible with the GMC-300MA?

A: Yes. MSC-300MA meets all core substitution criteria: 300 mA current rating, 250 V AC voltage rating, cartridge glass fuse type, and 5mm x 20mm package dimensions. MSC-300MA offers a higher breaking capacity (100A versus 35A) and extended operating temperature range (-55°C to 125°C) compared to Eaton variants.

Q: Do all substitute parts require the same fuse holder?

A: Yes. All substitute parts are 5mm x 20mm cartridge fuses and require a compatible 5x20mm fuse holder. The holder must be rated for 250 V AC operation and 300 mA minimum current capacity.

Q: What certifications apply to these fuse parts?

A: Eaton variants (GMC-300MA, GMC-300-R, BK/GMC-300-R, BK1/GMC-300-R) carry CSA, KC-MARK, and/or UL approvals. OptiFuse MSC-300MA carries cULus and UL 248 approvals. All parts are RoHS3 compliant.

Q: Can I substitute based on breaking capacity alone?

A: No. While breaking capacity is a technical specification, substitution must be based on the core parameters: current rating, voltage rating, fuse type, package dimensions, and response time. Breaking capacity is an additional consideration for application-specific requirements but does not determine interchangeability.