HS300 27R F Wirewound Chassis Mount Resistor - Equivalent & Substitute Parts

Part Overview

The HS300 27R F is a 300-watt wirewound chassis mount resistor manufactured by Ohmite, rated at 27 ohms with ±1% tolerance. This component is designed for high-power applications requiring stable resistance performance with pulse withstanding capability. The part is currently in active production status with RoHS compliance certification.

Substitute parts are identified when equivalent electrical parameters and mechanical mounting compatibility are maintained within the allowed specifications for this resistor category. Substitution becomes necessary when the primary part is unavailable, when inventory constraints require alternative sourcing, or when application requirements permit operation at reduced power ratings while maintaining core electrical characteristics.

Substiute Parts

HS300 27R F

OhmiteIn Stock: 1026HS300 27R F Datasheet

Current PartRFQ

HS250 27R F

ARCOLIn Stock: 971HS250 27R F Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the HS300 27R F is determined by the following critical parameters:

• Resistance Value: Must be exactly 27 ohms
• Tolerance: Must be ±1% or tighter
• Composition: Must be wirewound construction
• Housing Type: Must be aluminum for thermal compatibility
• Mounting Feature: Must include flanges for mechanical compatibility
• Lead Style: Must be M6 threaded for electrical connection compatibility
• RoHS Compliance: Must maintain RoHS compliant status

The HS250 27R F qualifies as a parametric equivalent substitute. While the power rating is reduced from 300W to 250W, all other critical electrical and mechanical parameters remain identical. This substitution is valid for applications where the 250W power dissipation capacity is sufficient for the circuit requirements.

Parameter Comparison

Engineering Selection Recommendations

Both the HS300 27R F and HS250 27R F maintain active production status with full RoHS compliance certification. Selection between these parts is determined by application power dissipation requirements.

The HS300 27R F is the primary specification when the circuit design requires 300-watt continuous power dissipation capability. The HS250 27R F serves as a substitute when circuit analysis confirms that maximum power dissipation does not exceed 250 watts under normal operating conditions.

Both parts share identical electrical characteristics (27 ohms, ±1% tolerance, wirewound construction) and mechanical mounting interfaces (M6 threaded leads, flange mounting, aluminum housing). The substitution is electrically and mechanically valid when thermal requirements are satisfied by the lower power rating.

Frequently Asked Questions (FAQ)

Q: Can the HS250 27R F replace the HS300 27R F in any application?

A: The HS250 27R F is electrically and mechanically compatible with the HS300 27R F. Substitution is valid only when the application's maximum continuous power dissipation does not exceed 250 watts. Thermal analysis of the circuit is required to confirm substitution eligibility.

Q: Are the physical dimensions compatible between these two parts?

A: Both parts use M6 threaded leads and flange mounting, ensuring mechanical compatibility in the circuit board or chassis assembly. The HS250 27R F has reduced overall dimensions (4.319" L x 1.791" W) compared to the HS300 27R F (5.028" L x 2.854" W), but both mount using identical lead spacing and flange configuration.

Q: Do both parts meet the same environmental compliance standards?

A: Both the HS300 27R F and HS250 27R F are RoHS compliant with MSL 1 (Unlimited) moisture sensitivity rating. Both carry identical ECCN (EAR99) and HTSUS (8533.29.0000) classifications.

Q: What is the primary difference between these substitute parts?

A: The sole difference is the power rating: 300W for the HS300 27R F and 250W for the HS250 27R F. All other specifications—resistance value, tolerance, temperature coefficient, construction type, and mounting interface—are identical.

Q: How do I determine if the HS250 27R F is suitable for my circuit?

A: Calculate the maximum continuous power dissipation in your circuit using P = I²R, where I is the maximum current through the resistor and R is 27 ohms. If this value does not exceed 250 watts, the HS250 27R F is a valid substitute.