Ohmite F55J1R5 Wirewound Chassis Mount Resistor – Equivalent & Substitute Parts

Part Overview

The Ohmite F55J1R5 is a 1.5 Ohms ±5% 55W wirewound chassis mount resistor from 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 921 units in stock. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and application-specific requirements where power rating or packaging variations may be acceptable.

Substiute Parts

F55J1R5

OhmiteIn Stock: 993F55J1R5 Datasheet

Current PartRFQ

F40J1R5E

OhmiteIn Stock: 892F40J1R5E Datasheet

Parametric EquivalentRFQ

F55J1R5E

OhmiteIn Stock: 1085F55J1R5E Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the F55J1R5 is determined by the following critical parameters:

Core Electrical Parameters (Non-Negotiable):

• Resistance value: 1.5 Ohms
• Tolerance: ±5%
• Composition: Wirewound
• Temperature Coefficient: ±400ppm/°C
• Operating Temperature Range: -55°C to 350°C

Mechanical Parameters (Substitution-Dependent):

• Mounting Feature: Flange Braces, Right Angle
• Lead Style: Solder Lugs
• Package/Case: Radial, Flat Oval
• Coating/Housing Type: Vitreous Enamel Coated

Variable Parameter (Allows Substitution):

• Power Rating: 55W (primary) or 40W (reduced-power alternative)

The F55J1R5 has two identified substitutes within the Stackohm® 250 series. The F55J1R5E maintains identical electrical and mechanical specifications with improved RoHS3 compliance. The F40J1R5E provides a lower power rating (40W) alternative with reduced physical dimensions, suitable for applications where thermal dissipation requirements are lower.

Parameter Comparison

Engineering Selection Recommendations

F55J1R5E (Direct Equivalent): The F55J1R5E is the preferred direct substitute for the F55J1R5. Both parts maintain identical electrical specifications (1.5 Ohms ±5%, 55W, ±400ppm/°C, -55°C to 350°C) and mechanical form factor (4.600" L x 1.000" W). The primary distinction is regulatory compliance: F55J1R5E achieves ROHS3 compliance, whereas the original F55J1R5 is RoHS non-compliant. For applications subject to RoHS3 requirements or future regulatory transitions, F55J1R5E is the recommended selection. Both parts are active products with comparable inventory availability.

F40J1R5E (Reduced-Power Alternative): The F40J1R5E is a parametric equivalent with reduced power rating (40W versus 55W). This part maintains all electrical parameters (1.5 Ohms ±5%, ±400ppm/°C, -55°C to 350°C) and mounting characteristics. The physical footprint is reduced (2.000" L x 1.000" W versus 4.600" L x 1.000" W), resulting in lower thermal mass and dissipation capability. F40J1R5E is suitable for applications where the 55W power rating exceeds thermal requirements and space constraints favor a smaller form factor. This part is ROHS3 compliant and carries active product status.

Selection between F55J1R5E and F40J1R5E depends on application power dissipation requirements and available board space. Both are ROHS3 compliant alternatives to the original F55J1R5.

Frequently Asked Questions (FAQ)

Q: Can F55J1R5E be used as a direct replacement for F55J1R5? A: Yes. F55J1R5E is a direct equivalent with identical electrical specifications (1.5 Ohms ±5%, 55W, ±400ppm/°C, -55°C to 350°C) and mechanical form factor. The primary difference is ROHS3 compliance status. Both parts are suitable for identical applications.

Q: What is the key difference between F55J1R5E and F40J1R5E? A: The primary difference is power rating: F55J1R5E is rated at 55W, while F40J1R5E is rated at 40W. F40J1R5E also has a reduced physical length (2.000" versus 4.600"). All other electrical parameters remain identical. Selection depends on application power dissipation requirements.

Q: Can F40J1R5E replace F55J1R5 in high-power applications? A: No. F40J1R5E has a lower power rating (40W) and should only be used in applications where the actual power dissipation does not exceed 40W. Using F40J1R5E in applications requiring 55W dissipation will result in component failure.

Q: Are all three parts (F55J1R5, F55J1R5E, F40J1R5E) from the same manufacturer? A: Yes. All three parts are manufactured by Ohmite and belong to the Stackohm® 250 series.

Q: What is the significance of RoHS compliance for these parts? A: F55J1R5 is RoHS non-compliant, while F55J1R5E and F40J1R5E are ROHS3 compliant. For applications or markets subject to RoHS3 regulations, only F55J1R5E or F40J1R5E are acceptable selections.

Q: Do all three parts have the same operating temperature range? A: Yes. All three parts operate across the identical temperature range of -55°C to 350°C with a temperature coefficient of ±400ppm/°C.

Q: What mounting considerations apply to these parts? A: All three parts feature flange braces with right-angle mounting and solder lugs for connection. The primary mechanical difference is physical length: F55J1R5 and F55J1R5E are 4.600" long, while F40J1R5E is 2.000" long. Board layout and thermal dissipation requirements should guide selection.