Sensata Technologies S322 SSR Relay SPST-NO 3A 40-280V Equivalent & Substitute Parts

Part Overview

The Sensata Technologies S322 is a solid-state relay (SSR) module configured as SPST-NO (Single Pole Single Throw - Normally Open) with a 3A load current rating and 40-280V AC output voltage range. This component is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system maintenance and new design implementations. The S322 operates with 4.6-8VDC input control voltage and features zero-cross switching for AC loads, typical of industrial control applications requiring galvanic isolation and silent switching characteristics.

Substiute Parts

S322

Sensata TechnologiesIn Stock: 752S322 Datasheet

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LR600240D25

Sensata-CrydomIn Stock: 3197LR600240D25 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

The LR600240D25 from Sensata-Crydom qualifies as a functional substitute based on the following alignment of critical electrical and mechanical parameters:

Matching Parameters:

• Circuit configuration: Both are SPST-NO (1 Form A) modules
• Output type: Both feature AC, Zero Cross switching
• Mounting type: Both are Through Hole
• Termination style: Both use PC Pin
• Package type: Both are Module format
• Moisture sensitivity: Both rated MSL 1 (Unlimited)

Substitution Basis: The LR600240D25 maintains the same control interface topology (DC input to AC output isolation) and switching mechanism (zero-cross AC relay). While the LR600240D25 offers higher load current capacity (25A vs. 3A) and extended input voltage range (4-32VDC vs. 4.6-8VDC), these represent performance enhancements rather than incompatibilities. The load voltage range (24-280V) encompasses the S322 specification (40-280V), ensuring compatibility with existing AC load circuits.

Parameter Comparison

Engineering Selection Recommendations

The LR600240D25 is the designated substitute for the obsolete S322 based on functional equivalence and active product status. The substitute maintains identical circuit topology, switching mechanism, and physical form factor, ensuring direct compatibility in existing through-hole PCB layouts.

The LR600240D25 carries ROHS3 compliance and REACH Affected status, representing current regulatory alignment compared to the S322's REACH Unaffected classification. Both components share EAR99 export control classification.

For applications requiring the exact 3A current specification of the S322, the LR600240D25's 25A rating provides operational margin without introducing incompatibility. The extended input voltage range (4-32VDC) accommodates broader control signal sources while remaining backward-compatible with 4.6-8VDC control circuits. The load voltage range extension to 24V minimum (versus 40V minimum on the S322) expands application flexibility without affecting existing 40-280V load circuits.

Frequently Asked Questions (FAQ)

Q: Can the LR600240D25 directly replace the S322 in existing circuit boards?

A: Yes. Both components share identical mounting type (Through Hole), termination style (PC Pin), and package format (Module). Physical and electrical interface compatibility is maintained. No PCB layout modifications are required.

Q: Does the higher current rating (25A vs. 3A) of the LR600240D25 create compatibility issues?

A: No. Higher current capacity does not create incompatibility. The substitute operates safely in circuits designed for 3A loads. The component will not force additional current through the load; current is determined by the load impedance and applied voltage.

Q: Are there regulatory or compliance differences between the S322 and LR600240D25?

A: The LR600240D25 is ROHS3 compliant and REACH Affected, reflecting current regulatory requirements. The S322 is REACH Unaffected, indicating its obsolete status predates current chemical substance regulations. Both share EAR99 export classification. For new designs or systems requiring current compliance documentation, the LR600240D25 is the appropriate selection.

Q: What is the significance of the extended input voltage range (4-32VDC) on the LR600240D25?

A: The LR600240D25 accepts control signals from 4-32VDC, compared to the S322's 4.6-8VDC range. This represents enhanced flexibility for control circuit design. Existing S322 circuits operating at 4.6-8VDC remain fully compatible, as this range falls within the LR600240D25 specification.

Q: Does the load voltage range difference (24-280V vs. 40-280V) affect substitution?

A: No. The LR600240D25 load voltage range encompasses the S322 specification. Existing circuits operating at 40-280V are fully compatible. The extended lower limit (24V) provides additional application flexibility for new designs without affecting existing implementations.

Q: What is zero-cross switching and why is it relevant to substitution?

A: Zero-cross switching synchronizes relay activation to the AC voltage waveform zero-crossing point, reducing electromagnetic interference and switching transients. Both the S322 and LR600240D25 implement this feature identically, ensuring equivalent switching performance and noise characteristics in AC load applications.