Equivalent & Substitute Parts for 5ET 1 Glass Cartridge Fuse

Part Overview

The Bel Fuse Inc. 5ET 1 is a 1 A, 250 V AC/DC slow blow glass cartridge fuse in 5mm x 20mm form factor. This part is currently obsolete, requiring identification of active equivalent and substitute components. Substitute parts must maintain electrical compatibility across current rating, voltage rating, response time, and mechanical dimensions while meeting applicable regulatory certifications.

Substiute Parts

5ET 1

Bel Fuse Inc.In Stock: 10625ET 1 Datasheet

Current PartRFQ

5ET 1-R

Bel Fuse Inc.In Stock: 162615ET 1-R Datasheet

DirectRFQ

5ST 1-R

Bel Fuse Inc.In Stock: 83655ST 1-R Datasheet

Parametric EquivalentRFQ

5TT 1-R

Bel Fuse Inc.In Stock: 385445TT 1-R Datasheet

Parametric EquivalentRFQ

0034.2516

SCHURTER Inc.In Stock: 46040034.2516 Datasheet

SimilarRFQ

0213001.MXP

Littelfuse Inc.In Stock: 105100213001.MXP Datasheet

SimilarRFQ

0218001.MXP

Littelfuse Inc.In Stock: 179530218001.MXP Datasheet

SimilarRFQ

0219001.MXAP

Littelfuse Inc.In Stock: 25890219001.MXAP Datasheet

SimilarRFQ

0239001.HXP

Littelfuse Inc.In Stock: 8910239001.HXP Datasheet

SimilarRFQ

BK1/GMD-1-R

Eaton - Electronics DivisionIn Stock: 1128BK1/GMD-1-R Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict equivalence across the following parameters:

• Current Rating: 1 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)

Parts are grouped into two categories:

Direct Manufacturer Equivalents — Same manufacturer (Bel Fuse Inc.), identical electrical and mechanical specifications, different product status or packaging.

Parametric Equivalents and Similar Parts — Different manufacturers, all core parameters match, but secondary characteristics (breaking capacity, melting I²t, DC cold resistance) may vary within acceptable ranges for the application.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: 5ET 1-R (Bel Fuse Inc.)

The 5ET 1-R is the direct active equivalent of the obsolete 5ET 1. It maintains identical electrical specifications (1 A, 250 V AC, slow blow response, 150 A breaking capacity, 28 melting I²t) and mechanical form factor. The part is ROHS3 compliant and carries the same regulatory certifications (CCC, CE, CSA, cULus, SEMKO, VDE). This is the preferred replacement for direct substitution.

Secondary Recommendations: 5ST 1-R and 5TT 1-R (Bel Fuse Inc.)

Both parts maintain core electrical parameters (1 A, 250 V AC, slow blow, 5mm x 20mm) and are ROHS3 compliant. The 5ST 1-R has lower breaking capacity (35 A) and melting I²t (2.4), while the 5TT 1-R offers intermediate breaking capacity (100 A) and melting I²t (8.63). These are suitable where application requirements permit variation in breaking capacity and thermal response characteristics.

Cross-Manufacturer Alternatives: Littelfuse Inc. and Eaton

Littelfuse 0218001.MXP, 0219001.MXAP, and 0239001.HXP maintain all core parameters and are ROHS3 compliant. The 0219001.MXAP matches the original 150 A breaking capacity and 19.2 melting I²t. Eaton BK1/GMD-1-R provides 100 A breaking capacity with 12 melting I²t. All cross-manufacturer parts carry appropriate regulatory certifications for their respective regions.

Not Recommended: 0034.2516 (SCHURTER Inc.)

This part specifies medium blow response time, which differs from the slow blow characteristic of the original 5ET 1. This response time difference may affect circuit protection behavior and is not suitable for direct substitution.

Frequently Asked Questions (FAQ)

Q: Can I use 5ST 1-R or 5TT 1-R as direct replacements for 5ET 1?

A: Yes. Both parts maintain the required 1 A current rating, 250 V AC voltage rating, slow blow response, and 5mm x 20mm mechanical form factor. The difference lies in breaking capacity and melting I²t values. Verify that your application does not require the specific 150 A breaking capacity and 28 melting I²t of the original part before substituting.

Q: What is the difference between breaking capacity and melting I²t?

A: Breaking capacity is the maximum fault current the fuse can safely interrupt. Melting I²t is a thermal characteristic indicating the energy required to melt the fuse element. Both parameters affect fuse performance under fault conditions. Consult your circuit design requirements to determine acceptable ranges.

Q: Are Littelfuse and Eaton parts compatible with my existing fuse holder?

A: Yes. All substitute parts maintain the 5mm x 20mm mechanical form factor and require a standard holder. Physical compatibility is assured. Verify that your holder is rated for 250 V AC operation.

Q: Why is 0034.2516 not recommended?

A: This SCHURTER part specifies medium blow response time, whereas the original 5ET 1 and all recommended substitutes are slow blow. Response time affects the fuse's thermal and magnetic response to overcurrent conditions. Using a different response time may compromise circuit protection performance.

Q: Which substitute offers the closest electrical match to the original 5ET 1?

A: The 5ET 1-R is the direct equivalent, maintaining identical breaking capacity (150 A) and melting I²t (28). For cross-manufacturer alternatives, Littelfuse 0219001.MXAP matches the 150 A breaking capacity and provides 19.2 melting I²t, offering the closest performance profile.

Q: Are all recommended substitutes RoHS compliant?

A: Yes. All active substitute parts listed are ROHS3 compliant. The original 5ET 1 is RoHS non-compliant. If RoHS compliance is required for your application, any of the recommended substitutes will satisfy this requirement.