Equivalent & Substitute Parts for Ohmite 810F75R

Part Overview

The Ohmite 810F75R is a 75 Ohms ±1% 10W wirewound chassis mount resistor from the Metal-Mite®89 series, designed for applications requiring precision resistive elements with high power dissipation capability. The main part is classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations. Substitute parts must maintain electrical equivalence across resistance value, tolerance, and power rating while accommodating mechanical and packaging variations.

Substiute Parts

810F75R

OhmiteIn Stock: 1060810F75R Datasheet

Current PartRFQ

810F75RE

OhmiteIn Stock: 1054810F75RE Datasheet

DirectRFQ

RH01075R00FC02

Vishay DaleIn Stock: 922RH01075R00FC02 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 810F75R is determined by the following critical parameters:

Electrical Equivalence Requirements:

• Resistance value: 75 Ohms (exact match required)
• Tolerance: ±1% (exact match required)
• Temperature coefficient: ±20ppm/°C (exact match required)
• Composition: Wirewound (exact match required)

Mechanical Compatibility Requirements:

• Mounting feature: Flanges (exact match required)
• Lead style: Solder Lugs (exact match required)
• Housing type: Aluminum (exact match required)
• Package/case: Axial, Box (exact match required)

Acceptable Variation Parameters:

• Power rating: Equal to or greater than 10W
• Operating temperature range: Must encompass or equal the original range
• Packaging format: May differ (Tray, Bulk acceptable)
• Product status: Active preferred for long-term availability

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: Ohmite 810F75RE

The 810F75RE is the direct functional equivalent of the 810F75R, maintaining identical electrical specifications and mechanical dimensions. This part is currently in active production status with 947 units in stock. The 810F75RE achieves ROHS3 compliance, making it suitable for applications subject to RoHS regulations. Packaging is supplied in Tray format rather than the original specification. This substitute provides the highest compatibility for direct replacement applications.

Secondary Substitute: Vishay Dale RH01075R00FC02

The RH01075R00FC02 meets all critical electrical and mechanical requirements with a higher power rating of 12.5W, providing additional thermal margin in applications where the original 10W rating is marginal. Dimensional variation is minimal (0.405" height versus 0.400" maximum). The operating temperature range is reduced to -55°C ~ 250°C, which may be limiting for applications requiring the full 275°C upper limit of the original part. This part maintains RoHS non-compliant status consistent with the original specification. Packaging is supplied in Bulk format.

Selection between these substitutes depends on regulatory compliance requirements (RoHS3 preferred for new designs) and thermal design margins (higher power rating beneficial for high-dissipation applications).

Frequently Asked Questions (FAQ)

Q: Can the 810F75RE directly replace the 810F75R in existing assemblies?

A: Yes. The 810F75RE maintains identical electrical parameters (75 Ohms ±1%, 10W, ±20ppm/°C) and mechanical dimensions (0.750" L x 0.812" W, 0.400" height). The only differences are product status (Active versus Obsolete) and RoHS compliance level. No circuit modifications or mechanical rework are required.

Q: What is the significance of the higher 12.5W power rating in the RH01075R00FC02?

A: The increased power rating indicates higher thermal capacity and lower operating temperature rise under the same current conditions. This provides design margin for applications operating near the original 10W thermal limit. However, the substitute must still be selected based on actual circuit power dissipation requirements.

Q: Are there dimensional compatibility concerns with the RH01075R00FC02?

A: Dimensional differences are minimal. The RH01075R00FC02 measures 0.750" L x 0.800" W (versus 0.812" W for the original) and 0.405" height (versus 0.400" maximum). These variations fall within typical PCB layout tolerances for chassis mount resistors with flanged mounting. Verify mounting hole spacing and clearance in your specific application.

Q: Why does the RH01075R00FC02 have a reduced operating temperature range?

A: The RH01075R00FC02 specifies -55°C ~ 250°C versus the original -55°C ~ 275°C. Applications requiring operation above 250°C must use the 810F75RE or equivalent Ohmite parts. For standard industrial and commercial temperature ranges, this limitation is not restrictive.

Q: What packaging format differences exist between these substitutes?

A: The main part (810F75R) and 810F75RE are available in different packaging: the original is unspecified, 810F75RE is supplied in Tray format, and RH01075R00FC02 is supplied in Bulk format. Packaging affects handling, storage, and component counting but does not affect electrical or mechanical performance.

Q: Is RoHS compliance a factor in selecting between these substitutes?

A: RoHS compliance is a regulatory requirement for products sold into certain markets. The 810F75RE achieves ROHS3 compliance, making it suitable for new designs subject to RoHS directives. The RH01075R00FC02 remains RoHS non-compliant. For legacy system support where the original part was non-compliant, either substitute is acceptable. For new designs, the 810F75RE is preferred.