A1240-10 Solid State Relay SPST-NO Equivalent & Substitute Parts

Part Overview

The A1240-10 is a Solid State Relay (SSR) with SPST-NO (1 Form A) configuration manufactured by Sensata-Crydom. This chassis-mounted hockey puck relay operates with AC output, accepting input voltage from 90 to 280VAC and controlling loads between 24V and 140V at 40A capacity. The component is RoHS compliant and currently in active production status with 1117 units in stock.

Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the allowed parameter ranges for this SSR category. Alternative models may be required due to inventory availability, lead time considerations, or application-specific voltage and current requirements.

Substiute Parts

A1240-10

Sensata-CrydomIn Stock: 1211A1240-10 Datasheet

Current PartRFQ

84134221

Sensata-CrydomIn Stock: 105584134221 Datasheet

MFR RecommendedRFQ

84137321N

CrouzetIn Stock: 91084137321N Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for SSR SPST-NO relays is determined by the following criteria:

Circuit Configuration: All substitute parts must maintain SPST-NO (1 Form A) topology with AC output capability.

Mechanical Compatibility: Chassis mount hockey puck package with screw terminal termination ensures physical and electrical interface compatibility.

Voltage Parameters: Substitute parts must support the input voltage range of 90 ~ 280VAC. Load voltage ranges may extend beyond the original specification (24 ~ 140V) provided the minimum threshold does not exceed 24V and the maximum does not fall below 140V.

Current Rating: Substitute parts must maintain or exceed the 40A load current specification.

Compliance: RoHS compliance status must be maintained for regulatory equivalence.

The identified substitute parts (84134221 and 84137321N) satisfy these criteria while offering extended voltage and current capabilities suitable for broader application requirements.

Parameter Comparison

Engineering Selection Recommendations

84134221 (Sensata-Crydom): This substitute maintains the same manufacturer lineage as the A1240-10 while providing increased load current capacity (50A vs. 40A) and extended load voltage range (24V ~ 280V). Input voltage compatibility remains identical at 90 ~ 280VAC. RoHS compliance and active product status ensure regulatory and supply chain continuity. This part is suitable for applications requiring the original A1240-10 specifications with margin for higher current or voltage demands.

84137321N (Crouzet): This substitute provides the highest load current rating (50A) and the widest load voltage range (48V ~ 660V) among available options. Input voltage range is slightly reduced to 90 ~ 260VAC. RoHS compliance and active product status are maintained. This part is suitable for applications with load voltage requirements exceeding 280V or where extended voltage operating range is necessary. Note that the minimum load voltage is 48V, which exceeds the original 24V specification.

Frequently Asked Questions (FAQ)

Q: Can the 84134221 directly replace the A1240-10 in all applications?

A: The 84134221 maintains identical input voltage range (90 ~ 280VAC) and supports the original load voltage range (24V ~ 140V) with additional capacity to 280V. The increased current rating (50A vs. 40A) provides operational margin. Direct substitution is valid for applications within the original A1240-10 specifications.

Q: What is the key difference between the two substitute parts?

A: The 84134221 extends load voltage capability to 280V while maintaining the 24V minimum threshold. The 84137321N extends load voltage to 660V but establishes a 48V minimum threshold, making it unsuitable for applications requiring 24V ~ 40V operation. Both provide 50A current capacity.

Q: Is the 84137321N compatible with 24V load applications?

A: No. The 84137321N specifies a minimum load voltage of 48V, which exceeds the original A1240-10 minimum of 24V. This part is not suitable for applications requiring operation below 48V load voltage.

Q: Are all substitute parts RoHS compliant?

A: Yes. Both 84134221 and 84137321N maintain RoHS compliance status, ensuring regulatory equivalence with the A1240-10.

Q: Does packaging differ between the main part and substitutes?

A: The A1240-10 and 84134221 are supplied in bulk packaging. The 84137321N is supplied in box packaging. All three maintain identical hockey puck mechanical form factor and screw terminal interface.

Q: What is the input voltage limitation for the 84137321N?

A: The 84137321N input voltage range is 90 ~ 260VAC, which is 20V lower than the A1240-10 specification of 90 ~ 280VAC. Applications requiring input voltage between 260VAC and 280VAC are not compatible with this substitute.