GMD-300-R Equivalent & Substitute Parts

Part Overview

The GMD-300-R is a 300 mA, 250 V AC/DC glass cartridge fuse manufactured by Eaton - Electronics Division. This slow-blow fuse is designed for applications requiring overcurrent protection in a 5mm x 20mm form factor and operates with a holder-based mounting configuration. The part maintains active product status with 853 units in current inventory. Equivalent and substitute parts are identified to support procurement flexibility, supply chain continuity, and application-specific requirements where parametric compatibility is maintained.

Substiute Parts

GMD-300-R

Eaton - Electronics DivisionIn Stock: 927GMD-300-R Datasheet

Current PartRFQ

BK/GMD-300-R

Eaton - Electronics DivisionIn Stock: 1279BK/GMD-300-R Datasheet

DirectRFQ

TSC-300MA

OptiFuseIn Stock: 4921TSC-300MA Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the GMD-300-R are classified into two categories based on parametric equivalence:

Direct Manufacturer Equivalent (BK/GMD-300-R): This substitute maintains identical electrical and mechanical specifications with the main part. Both the current rating (300 mA), voltage rating (250 V AC), fuse type (cartridge glass), response time (slow blow), and physical dimensions (5mm x 20mm) are identical. The breaking capacity, melting I²t, and DC cold resistance are equivalent. Both parts carry CSA and UL approvals and are ROHS3 compliant. This classification represents a direct interchangeable substitute with no functional or performance differences.

Parametric Equivalent (TSC-300MA): This substitute from OptiFuse maintains the critical electrical parameters: 300 mA current rating, 250 V AC voltage rating, slow-blow response time, and identical 5mm x 20mm physical dimensions. The fuse type (cartridge glass) and mounting requirement (holder-based) are identical. Parametric equivalence is established through matching current rating, voltage rating, response time, and form factor. Differences exist in breaking capacity (100A versus 35A), melting I²t (0.4817 versus 0.65), and approval agencies (cULus, UL 248 versus CSA, UL). The TSC-300MA operates across an extended temperature range (-55°C to 125°C) and carries UL 248 certification.

Parameter Comparison

Engineering Selection Recommendations

BK/GMD-300-R Selection: This part is recommended for direct replacement applications where Eaton GMD series continuity is required. The identical electrical specifications, matching approval agencies (CSA, UL), and equivalent mechanical parameters ensure seamless integration into existing designs. This substitute is suitable for applications with standard operating temperature ranges and where CSA certification is a procurement requirement. Current inventory of 1185 units supports immediate availability.

TSC-300MA Selection: This OptiFuse substitute is suitable for applications where the higher breaking capacity (100A) and extended operating temperature range (-55°C to 125°C) provide performance advantages. The cULus and UL 248 certifications satisfy North American regulatory requirements. The lower melting I²t value (0.4817) indicates faster thermal response characteristics. This substitute is appropriate for environments with wider temperature extremes or where UL 248 certification is specified. Current inventory of 4899 units provides extended supply availability.

Both substitutes maintain the critical parameters of 300 mA current rating, 250 V AC voltage rating, slow-blow response time, and 5mm x 20mm form factor, ensuring mechanical and electrical compatibility with GMD-300-R holder-based mounting systems.

Frequently Asked Questions (FAQ)

Q: Can TSC-300MA be used in place of GMD-300-R in all applications?

A: TSC-300MA maintains parametric equivalence in current rating (300 mA), voltage rating (250 V AC), response time (slow blow), and physical dimensions (5mm x 20mm). The higher breaking capacity (100A versus 35A) and lower melting I²t (0.4817 versus 0.65) represent performance differences. Substitution is valid where these characteristics are compatible with circuit requirements and where cULus/UL 248 certifications satisfy regulatory needs.

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

A: BK/GMD-300-R is a direct equivalent with identical electrical and mechanical specifications. Both parts are manufactured by Eaton, carry the same approvals (CSA, UL), and share equivalent breaking capacity, melting I²t, and DC cold resistance values. The designation difference reflects packaging or distribution channel variation within the Eaton product line.

Q: Are all three parts physically interchangeable?

A: Yes. All three parts share identical physical dimensions (5mm x 20mm), require holder-based mounting, and are classified as cartridge glass fuses. Physical interchangeability is confirmed across the GMD-300-R, BK/GMD-300-R, and TSC-300MA.

Q: Which substitute has better availability?

A: TSC-300MA from OptiFuse currently has the highest inventory level at 4899 units, followed by BK/GMD-300-R at 1185 units, and GMD-300-R at 853 units.

Q: Do all parts meet RoHS requirements?

A: Yes. GMD-300-R, BK/GMD-300-R, and TSC-300MA are all ROHS3 compliant.

Q: What approval agencies certify each part?

A: GMD-300-R and BK/GMD-300-R carry CSA and UL approvals. TSC-300MA carries cULus and UL 248 certifications. Both certification sets satisfy North American regulatory requirements for fuse products.