2JS 250-R Equivalent & Substitute Parts

Part Overview

The 2JS 250-R is a 250 mA slow-blow glass cartridge fuse manufactured by Bel Fuse Inc., rated for 350 V AC and 140 V DC operation. This component is classified as obsolete, necessitating identification of active equivalent alternatives for continued system support and procurement. The fuse requires a 2AG holder and operates across an extended temperature range of -55°C to 125°C. Substitute parts must maintain identical current ratings, package dimensions, and mechanical compatibility while meeting or exceeding the voltage and breaking capacity specifications of the original design.

Substiute Parts

2JS 250-R

Bel Fuse Inc.In Stock: 10972JS 250-R Datasheet

Current PartRFQ

0209.250MXP

LittelfuseIn Stock: 26270209.250MXP Datasheet

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0229.250MXP

Littelfuse Inc.In Stock: 10520229.250MXP Datasheet

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BK/C519-250-R

Eaton - Electronics DivisionIn Stock: 1169BK/C519-250-R Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2JS 250-R is determined by the following mandatory parameters:

• Current Rating: 250 mA (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 2AG, 5mm x 15mm (exact match required)
• Voltage Rating - AC: Minimum 350 V
• Voltage Rating - DC: Minimum 140 V (where specified)
• Mounting Type: Requires Holder (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (minimum requirement)

The substitute parts identified below meet the core electrical and mechanical compatibility criteria. However, voltage ratings and breaking capacity specifications vary among alternatives, requiring application-specific evaluation based on circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

0209.250MXP (Littelfuse Series 209) provides the closest electrical match to the 2JS 250-R, maintaining 350 V AC rating and 100A breaking capacity. This part is active in production with ROHS3 compliance and CE/cULus certifications. Physical dimensions vary slightly (4.50mm diameter vs. 5.10mm), though both conform to the 2AG package standard. This substitute is suitable for applications requiring the full 350 V AC specification.

0229.250MXP (Littelfuse Series 229) is an active alternative with comprehensive certifications (CE, CSA, UL) and ROHS3 compliance. However, this part is rated for 250 V AC and 125 V DC, representing a voltage derating compared to the original specification. The 10kA DC breaking capacity exceeds the original 150A DC rating. This substitute is applicable only in circuits where the reduced voltage ratings are acceptable.

BK/C519-250-R (Eaton C519 Series) is an active product with CSA and UL certifications and RoHS compliance. This part is rated for 250 V AC only, with no DC voltage specification provided. The 35A breaking capacity is significantly lower than the original 100A AC specification. This substitute is suitable only for applications with reduced voltage and breaking capacity requirements.

All three substitutes maintain the 250 mA current rating, slow-blow response characteristic, and 2AG package compatibility required for mechanical and electrical interchangeability within their respective voltage and breaking capacity limitations.

Frequently Asked Questions (FAQ)

Q: Can the 0209.250MXP directly replace the 2JS 250-R in all applications?

A: The 0209.250MXP maintains the critical electrical parameters of 250 mA current rating and 350 V AC voltage rating, along with equivalent 100A breaking capacity. Physical dimensions are within 2AG package tolerance. This substitute is suitable for applications operating at or below 350 V AC. DC voltage operation requires circuit-specific evaluation, as the 0209.250MXP does not specify a DC rating.

Q: What is the voltage derating impact of using the 0229.250MXP?

A: The 0229.250MXP is rated for 250 V AC and 125 V DC, compared to the original 350 V AC and 140 V DC. This represents a 100 V AC and 15 V DC reduction in voltage capability. This substitute is applicable only in circuits designed for 250 V AC or lower operation. Use in higher-voltage circuits will compromise fuse protection and safety margins.

Q: Are all substitute parts mechanically compatible with existing 2AG fuse holders?

A: All substitute parts conform to the 2AG package standard and are designed for 2AG holders. Minor dimensional variations exist (diameter range 4.50mm to 5.20mm, length range 14.48mm to 14.50mm), but these fall within standard 2AG holder tolerances. Physical compatibility is confirmed for all listed substitutes.

Q: Which substitute offers the best compliance profile for new designs?

A: The 0229.250MXP provides the most comprehensive certification coverage (CE, CSA, UL) and is the only substitute with specified DC voltage rating (125 V DC). However, this part requires acceptance of reduced AC voltage rating (250 V vs. 350 V). The 0209.250MXP offers superior voltage rating (350 V AC) with active production status and ROHS3 compliance, though with fewer certifications than the 0229.250MXP.

Q: What is the significance of the melting I²t parameter differences?

A: The melting I²t values (0.41 for 2JS 250-R, 0.216 for 0209.250MXP and 0229.250MXP, 0.467 for BK/C519-250-R) indicate thermal energy absorption characteristics. Lower I²t values indicate faster thermal response. These differences reflect design variations among manufacturers but do not affect the 250 mA current rating or slow-blow classification. Application-specific thermal analysis is required if precise I²t matching is a circuit requirement.