BK/ETF-3.15 Equivalent & Substitute Parts Reference

Part Overview

The BK/ETF-3.15 is a 3.15 A board mount radial fuse rated for 277 V AC, manufactured by Eaton - Electronics Division as part of the ETF series. This component is classified as obsolete, necessitating identification of equivalent substitute parts for ongoing applications. The fuse features slow blow response characteristics and is designed for through-hole radial mounting in vertical orientation. Due to its obsolete status, sourcing equivalent alternatives with compatible electrical and mechanical specifications is required for system continuity and component availability.

Substiute Parts

BK/ETF-3.15

Eaton - Electronics DivisionIn Stock: 860BK/ETF-3.15 Datasheet

Current PartRFQ

SR-5-3.15A-BK

Eaton - Electronics DivisionIn Stock: 1088SR-5-3.15A-BK Datasheet

SimilarRFQ

0034.6620

SCHURTER Inc.In Stock: 112050034.6620 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BK/ETF-3.15 are identified based on the following critical parameters that determine functional equivalence:

Primary Matching Criteria:

• Current Rating: 3.15 A (exact match required)
• Response Time: Slow Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Radial, Can, Vertical (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)

Secondary Compatibility Criteria:

• Voltage Rating - AC: Minimum 277 V (equal or higher acceptable)
• Operating Temperature Range: Minimum -55°C ~ 125°C (equal or wider acceptable)
• Approval Agencies: Compliance with SEMKO and/or UL (or equivalent international standards)

Dimensional Tolerance:

• Physical size must accommodate through-hole radial mounting in vertical orientation

The two substitute parts identified meet the primary matching criteria with variations in voltage rating and approval certifications as detailed in the parameter comparison table.

Parameter Comparison

Engineering Selection Recommendations

SR-5-3.15A-BK Selection Criteria:

The SR-5-3.15A-BK is an active product manufactured by Eaton - Electronics Division, the same manufacturer as the obsolete BK/ETF-3.15. This substitute maintains identical current rating, response time, and mounting configuration. The AC voltage rating is reduced from 277 V to 250 V, which represents a design constraint for applications operating at or above 277 V AC. The operating temperature range is narrower (-40°C ~ 85°C versus -55°C ~ 125°C). This substitute is suitable for applications operating at 250 V AC or lower. The breaking capacity is reduced to 35 A. Approval certifications include SEMKO and cULus, providing continuity with the original part's SEMKO and UL compliance.

0034.6620 Selection Criteria:

The 0034.6620 is an active product manufactured by SCHURTER Inc., classified as MST 250 series. This substitute maintains identical current rating, response time, and mounting configuration. The AC voltage rating is 250 V, with additional DC rating of 125 V, providing dual-voltage capability. The operating temperature range matches the original part (-55°C ~ 125°C). The breaking capacity is 35 A AC and 50 A DC. This substitute is suitable for applications requiring both AC and DC voltage ratings at 250 V AC or lower. Approval certifications include VDE and PSE/JET compliance. Both substitute parts are ROHS3 compliant and REACH unaffected.

Application Voltage Consideration:

Applications requiring 277 V AC operation cannot use either substitute part without circuit redesign, as both substitutes are rated for 250 V AC maximum. For applications operating at 250 V AC or lower, both substitutes are electrically compatible based on current rating, response time, and melting I²t characteristics.

Frequently Asked Questions (FAQ)

Q1: Can the SR-5-3.15A-BK or 0034.6620 be used as direct replacements for the BK/ETF-3.15 in a 277 V AC circuit?

A: No. Both substitute parts are rated for 250 V AC maximum. The BK/ETF-3.15 is rated for 277 V AC. Using a 250 V rated fuse in a 277 V circuit exceeds the component's voltage rating and violates electrical safety standards. Circuit redesign or voltage reduction is required.

Q2: What are the key electrical parameters that must match between the main part and substitute?

A: Current rating (3.15 A), response time (Slow Blow), mounting type (Through Hole), and package configuration (Radial, Can, Vertical) must be identical. Voltage rating must be equal to or greater than the original specification. Melting I²t values should be comparable to maintain circuit protection characteristics.

Q3: Are there dimensional differences between the main part and substitutes?

A: Yes. The BK/ETF-3.15 measures 0.329" Dia x 0.303" H (8.35mm x 7.70mm). The SR-5-3.15A-BK measures 0.335" Dia x 0.319" H (8.50mm x 8.10mm). The 0034.6620 measures 0.335" Dia x 0.335" H (8.50mm x 8.50mm). These dimensional variations must be verified against PCB layout and mounting hole specifications before implementation.

Q4: What is the difference in breaking capacity between the main part and substitutes?

A: The BK/ETF-3.15 has a breaking capacity of 100 A at rated voltage. Both substitutes have a breaking capacity of 35 A (SR-5-3.15A-BK) or 35 A AC / 50 A DC (0034.6620). Breaking capacity defines the maximum fault current the fuse can safely interrupt. Applications with fault currents exceeding 35 A require evaluation of circuit protection adequacy.

Q5: Which substitute part offers the widest operating temperature range?

A: The 0034.6620 matches the original BK/ETF-3.15 operating temperature range of -55°C ~ 125°C. The SR-5-3.15A-BK has a narrower range of -40°C ~ 85°C. For applications requiring operation below -40°C or above 85°C, the 0034.6620 is the appropriate selection.

Q6: Are both substitute parts compliant with international safety standards?

A: Yes. The SR-5-3.15A-BK holds certifications from CCC, cULus, KC-MARK, PSE, SEMKO, and VDE. The 0034.6620 holds certifications from CCC, cURus, KC, PSE/JET, and VDE. Both parts are ROHS3 compliant and REACH unaffected. The original BK/ETF-3.15 held SEMKO and UL certifications; both substitutes maintain SEMKO or equivalent compliance.

Q7: What is the inventory status of each part?

A: The BK/ETF-3.15 (obsolete) has 768 pcs in stock. The SR-5-3.15A-BK (active) has 1054 pcs in stock. The 0034.6620 (active) has 11180 pcs in stock. Active products offer superior long-term availability compared to obsolete inventory.

Q8: Can the 0034.6620 be used in DC applications?

A: The 0034.6620 is rated for 125 V DC, making it suitable for DC applications at or below 125 V. The BK/ETF-3.15 and SR-5-3.15A-BK do not specify DC voltage ratings. For DC circuit applications, the 0034.6620 is the only substitute with documented DC capability.