BK/GDC-2.5A Equivalent & Substitute Parts

Part Overview

The BK/GDC-2.5A is a 2.5 A, 250 V AC/DC glass cartridge fuse with 5mm x 20mm form factor manufactured by Eaton - Electronics Division. This slow-blow fuse cartridge requires a holder for installation and is classified as Active product status. Substitute parts are identified when equivalent electrical and mechanical parameters are maintained across the same fuse category, enabling seamless integration into existing circuit protection designs without functional compromise.

Key Parameters

Parameter	Value
Current Rating	2.5 A
Voltage Rating (AC)	250 V
Fuse Type	Cartridge, Glass
Package / Case	5mm x 20mm
Response Time	Slow Blow
Mounting Type	Requires Holder
Breaking Capacity @ Rated Voltage	35 A
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution eligibility for the BK/GDC-2.5A is determined by strict alignment of the following critical parameters:

Primary Substitution Criteria:

Current Rating: 2.5 A (exact match required)
Voltage Rating (AC): 250 V (exact match required)
Package / Case: 5mm x 20mm (exact match required)
Fuse Type: Cartridge, Glass (exact match required)
Response Time: Slow Blow (exact match required)
Mounting Type: Requires Holder (exact match required)

Secondary Compatibility Parameters:

Breaking Capacity @ Rated Voltage: 35 A or higher
Melting I²t: Variation permitted within application tolerance
DC Cold Resistance: Variation permitted
RoHS Status: ROHS3 Compliant (preferred)

Parts are grouped into two categories: Direct Manufacturer Equivalents (same manufacturer, Eaton) and Cross-Manufacturer Parametric Equivalents (alternative manufacturers meeting all primary criteria).

Parameter Comparison

Part Number	Manufacturer	Series	Current (A)	Voltage (V)	Package	Response Time	Breaking Capacity (A)	Melting I²t	DC Cold Resistance (Ω)	Inventory (Pcs)
BK/GDC-2.5A	Eaton	GDC	2.5	250	5x20mm	Slow Blow	35	59.4	0.0255	1043
BK/S506-2.5-R	Eaton	S506	2.5	250	5x20mm	Slow Blow	35	59.4	0.0255	3012
BK/GMD-2.5-R	Eaton	GMD	2.5	250	5x20mm	Slow Blow	100	94	0.0905	1255
BK1/S506-2.5-R	Eaton	S506	2.5	250	5x20mm	Slow Blow	35	59.4	0.0255	2678
GDC-2.5A	Eaton	GDC	2.5	250	5x20mm	Slow Blow	35	59.4	0.0255	922
S506-2.5-R	Eaton	S506	2.5	250	5x20mm	Slow Blow	35	59.4	0.0255	816
0034.3121	SCHURTER	FST 5x20	2.5	250	5x20mm	Slow Blow	35	21.9	—	2136
021802.5HXP	Littelfuse	218	2.5	250	5x20mm	Slow Blow	35	23.25	0.0219	21272
021802.5MXP	Littelfuse	218	2.5	250	5x20mm	Slow Blow	35	23.25	0.0219	11400
0034.3780	SCHURTER	FSL 5x20	2.5	250	5x20mm	Slow Blow	100	9.45	—	1752
0034.5047	SCHURTER	FTT 5x20	2.5	250	5x20mm	Slow Blow	35	258	—	1232

Engineering Selection Recommendations

Eaton Direct Equivalents (Preferred for OEM Continuity):

BK/S506-2.5-R and BK1/S506-2.5-R are direct Eaton alternatives with identical electrical parameters to BK/GDC-2.5A. Both maintain 2.5 A current rating, 250 V voltage rating, 35 A breaking capacity, and 59.4 Melting I²t. BK/S506-2.5-R carries expanded approval certifications (BSI, CCC, CSA, CURUS, IMQ, PSE/JET, SEMKO, VDE) compared to the main part. Inventory availability is higher for BK/S506-2.5-R (3012 pcs) and BK1/S506-2.5-R (2678 pcs).

GDC-2.5A and S506-2.5-R are additional Eaton variants within the same electrical specification range, with GDC-2.5A sharing the identical series designation as the main part.

BK/GMD-2.5-R is an Eaton alternative with enhanced breaking capacity (100 A vs. 35 A) and higher Melting I²t (94 vs. 59.4). This part is suitable for applications requiring greater fault current handling capability while maintaining the 2.5 A current rating and 250 V voltage rating.

Cross-Manufacturer Equivalents (Alternative Supply Sources):

Littelfuse 021802.5HXP and 021802.5MXP (Series 218) meet all primary substitution criteria with identical 2.5 A, 250 V, 5x20mm specifications and slow-blow response. Both carry comprehensive international certifications (CCC, CE, CSA, K-MARK, PSE, SEMKO, UL, VDE). Melting I²t values (23.25) differ from the main part but remain within the slow-blow fuse category. Littelfuse parts offer the highest inventory availability (21272 pcs for HXP variant, 11400 pcs for MXP variant).

SCHURTER 0034.3121 (FST 5x20 series) is a direct parametric equivalent with matching 2.5 A, 250 V, 35 A breaking capacity specifications. Operating temperature range is specified (-55°C ~ 125°C).

SCHURTER 0034.3780 (FSL 5x20 series) provides enhanced breaking capacity (100 A) with lower Melting I²t (9.45), suitable for applications requiring faster response characteristics within the slow-blow category.

SCHURTER 0034.5047 (FTT 5x20 series) maintains 2.5 A and 250 V ratings with significantly higher Melting I²t (258), providing extended thermal capacity for inrush current applications.

Compliance Considerations:

All substitute parts maintain ROHS3 compliance. Littelfuse and SCHURTER parts carry REACH Unaffected status. Approval agency coverage varies; Littelfuse parts provide the broadest international certification scope. Selection should align with end-application regulatory requirements and geographic market certifications.

Frequently Asked Questions (FAQ)

Q: Can BK/GDC-2.5A be replaced with any 2.5 A fuse in a 5x20mm package?

A: No. Substitution requires exact matching of current rating (2.5 A), voltage rating (250 V AC), fuse type (cartridge, glass), response time (slow blow), and package dimensions (5x20mm). Additional parameters such as breaking capacity and Melting I²t must remain within application tolerance. Cross-manufacturer substitutes must meet all primary criteria.

Q: What is the difference between BK/S506-2.5-R and BK/GDC-2.5A?

A: Both parts share identical electrical specifications: 2.5 A current rating, 250 V voltage rating, 35 A breaking capacity, 59.4 Melting I²t, and 5x20mm package. The primary difference is series designation (S506 vs. GDC) and approval agency coverage. BK/S506-2.5-R carries additional international certifications (BSI, CCC, SEMKO, VDE) and higher inventory availability (3012 pcs vs. 1043 pcs).

Q: Why do Littelfuse and SCHURTER fuses have different Melting I²t values than the Eaton main part?

A: Melting I²t represents the thermal energy required to melt the fuse element and is a characteristic of fuse design and construction. Different manufacturers employ different element materials and geometries, resulting in variation in Melting I²t while maintaining the same current rating and response time classification. All slow-blow fuses in this comparison meet the 2.5 A rating and slow-blow response requirement.

Q: Is BK/GMD-2.5-R a suitable substitute for BK/GDC-2.5A?

A: BK/GMD-2.5-R is a parametric equivalent with identical current and voltage ratings and the same 5x20mm package. However, it features enhanced breaking capacity (100 A vs. 35 A) and higher Melting I²t (94 vs. 59.4). This part is suitable for applications requiring greater fault current handling. Verify application requirements before substitution.

Q: What is the difference between 021802.5HXP and 021802.5MXP from Littelfuse?

A: Both parts are from the Littelfuse 218 series with identical electrical specifications: 2.5 A, 250 V, 35 A breaking capacity, 23.25 Melting I²t, and 5x20mm package. The designation suffix (HXP vs. MXP) indicates different packaging or marking variants. Electrical performance is equivalent; selection may depend on packaging requirements or internal inventory coding.

Q: Can SCHURTER 0034.3780 replace BK/GDC-2.5A?

A: SCHURTER 0034.3780 meets all primary substitution criteria (2.5 A, 250 V, 5x20mm, slow blow, cartridge glass). However, it features enhanced breaking capacity (100 A vs. 35 A) and significantly lower Melting I²t (9.45 vs. 59.4), indicating faster thermal response. This part is suitable only if the application requires faster fuse response characteristics. Verify circuit protection requirements before substitution.

Q: Which substitute part offers the best inventory availability?

A: Littelfuse 021802.5HXP offers the highest inventory availability with 21272 pcs in stock, followed by 021802.5MXP with 11400 pcs. Among Eaton parts, BK/S506-2.5-R provides 3012 pcs. Littelfuse parts are recommended for applications requiring immediate availability and high-volume procurement.

Q: Are all substitute parts RoHS3 compliant?

A: All listed substitute parts are RoHS3 compliant. REACH status varies: Littelfuse and SCHURTER parts are marked as REACH Unaffected. Eaton parts show either ROHS3 Compliant or Vendor Undefined REACH status. Verify REACH compliance requirements for your specific application and geographic market.

Q: What approval agencies are most critical for industrial applications?

A: UL, CSA, and VDE certifications are standard for North American and European industrial applications. Littelfuse 021802.5HXP and 021802.5MXP carry all three certifications plus additional international approvals (CCC, CE, K-MARK, PSE, SEMKO). SCHURTER parts carry varying certification subsets. Select based on end-application geographic market and regulatory requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message