F55J250 Equivalent & Substitute Parts

Part Overview

The F55J250 is a 250 Ohms ±5% 55W wirewound chassis mount resistor manufactured by Ohmite in the Stackohm® 250 series. This component is designed for high-power applications requiring stable resistance performance across extended temperature ranges. The part is currently active in production with 924 units in stock. Equivalent and substitute parts are identified when applications require alternative power ratings, compliance certifications, or packaging configurations while maintaining core electrical specifications.

Substiute Parts

F55J250

OhmiteIn Stock: 1011F55J250 Datasheet

Current PartRFQ

F30J250E

OhmiteIn Stock: 912F30J250E Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The F30J250E qualifies as a parametric equivalent based on the following criteria:

Matching Parameters:

• Resistance value: 250 Ohms
• Tolerance: ±5%
• Composition: Wirewound
• Temperature Coefficient: ±260ppm/°C
• Operating Temperature Range: -55°C to 350°C
• Coating/Housing Type: Vitreous Enamel Coated
• Mounting Feature: Flange Braces, Right Angle
• Lead Style: Solder Lugs
• Package/Case: Radial, Flat Oval
• Manufacturer: Ohmite
• Series: Stackohm® 250

Differing Parameter:

• Power Rating: 30W (versus 55W in F55J250)

The F30J250E is suitable for applications where the 55W power dissipation of the F55J250 exceeds circuit requirements. The reduced physical size (1.250" L x 1.000" W versus 4.600" L x 1.000" W) accommodates space-constrained designs while maintaining identical electrical performance and temperature stability.

Parameter Comparison

Engineering Selection Recommendations

F55J250 Selection Criteria:

• Applications requiring 55W continuous power dissipation
• Designs where maximum thermal capacity is specified
• Systems not subject to RoHS3 compliance requirements

F30J250E Selection Criteria:

• Applications with power dissipation requirements of 30W or less
• Designs requiring ROHS3 compliance certification
• Space-constrained layouts where reduced component footprint is advantageous
• Both parts maintain identical electrical characteristics and temperature stability

Both parts are active products with current manufacturing status and adequate inventory availability.

Frequently Asked Questions (FAQ)

Q: Can F30J250E replace F55J250 in all applications? A: F30J250E is suitable only for applications where actual power dissipation does not exceed 30W. Verify circuit power requirements before substitution. Both parts provide identical resistance, tolerance, and temperature coefficient performance.

Q: What is the primary difference between these parts? A: The F30J250E has a 30W power rating and smaller physical dimensions (1.250" L) compared to the F55J250 (55W, 4.600" L). All other electrical and mechanical specifications are identical.

Q: Does the F30J250E meet RoHS compliance? A: Yes, F30J250E is ROHS3 compliant. The F55J250 is RoHS non-compliant. This distinction is relevant for applications subject to RoHS regulatory requirements.

Q: Are the mounting features identical? A: Yes. Both parts feature flange braces with right-angle mounting and solder lugs. Physical height when seated is identical at 0.563" (14.29mm).

Q: What is the temperature stability of these resistors? A: Both parts have a temperature coefficient of ±260ppm/°C and operate across the range of -55°C to 350°C, providing stable performance across extended thermal environments.

Q: Can these parts be used interchangeably in PCB layouts? A: No. The F30J250E has a shorter length (1.250" versus 4.600"). PCB mounting hole spacing and component placement must be verified before substitution.