Circuit Breaker Thermal Magnetic 4A 277V 65V DIN Rail - SCHURTER 4420.0173

Part Overview

The SCHURTER 4420.0173 is a single-pole thermal magnetic circuit breaker rated for 4A at 277V AC and 65V DC, designed for DIN rail mounting with lever actuation. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing system maintenance and new installations where this specific model is no longer available from the manufacturer.

Substiute Parts

4420.0173

SCHURTER Inc.In Stock: 10744420.0173 Datasheet

Current PartRFQ

7940112057

WeidmüllerIn Stock: 9747940112057 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SCHURTER 4420.0173 is determined by the following critical parameters that must remain consistent or compatible:

• Mounting Type: DIN Rail (required for mechanical fit)
• Breaker Type: Thermal Magnetic (required for protection characteristics)
• Voltage Rating - AC: 277V (required for circuit compatibility)
• Voltage Rating - DC: 65V (required for circuit compatibility)
• Actuator Type: Lever (required for operational interface)
• Number of Poles: 1 (required for circuit configuration)
• Current Rating: Must be equal to or greater than 4A to maintain or improve protection capability

The Weidmüller 7940112057 qualifies as a substitute because it maintains all critical parameters while offering a higher current rating of 6A, which provides equivalent or enhanced protection in the same circuit configuration.

Parameter Comparison

Engineering Selection Recommendations

The Weidmüller 7940112057 is the qualified substitute for the obsolete SCHURTER 4420.0173. Selection is based on the following engineering criteria:

• Functional Equivalence: Both components are single-pole thermal magnetic circuit breakers with identical voltage ratings (277V AC, 65V DC) and identical mechanical interfaces (DIN rail mounting, lever actuation).
• Current Rating Consideration: The Weidmüller part is rated at 6A compared to the SCHURTER's 4A. This higher rating provides equivalent or enhanced protection and is suitable for circuits originally designed for 4A protection.
• Regulatory Compliance: The Weidmüller part maintains compliance with UL1077 and CSA C22.2 No 235, which are the common certifications shared with the original part. The substitute meets current RoHS requirements.
• Product Availability: The Weidmüller part is in active production status with confirmed inventory, ensuring long-term availability for replacement and new installations.

Frequently Asked Questions (FAQ)

Q: Can the Weidmüller 7940112057 directly replace the SCHURTER 4420.0173 in existing installations?

A: Yes. Both components share identical mounting type (DIN rail), breaker type (thermal magnetic), voltage ratings (277V AC, 65V DC), actuator type (lever), and pole configuration (1-pole). The mechanical and electrical interfaces are compatible.

Q: Why is the Weidmüller part rated at 6A instead of 4A?

A: The higher current rating does not prevent substitution. A 6A-rated breaker provides equivalent or enhanced protection in a circuit designed for 4A operation. The breaker will trip at the same thermal and magnetic thresholds relative to its rated capacity.

Q: Are there any compliance differences between the two parts?

A: Both parts comply with UL1077 and CSA C22.2 No 235. The Weidmüller part meets current RoHS requirements, while the SCHURTER part is RoHS3 compliant. Both are REACH unaffected. Compliance is maintained across the substitution.

Q: What is the packaging difference?

A: The SCHURTER part is supplied with unspecified packaging, while the Weidmüller part is supplied in bulk packaging. This affects logistics and inventory management but does not impact functional compatibility.

Q: Is the Weidmüller part suitable for both AC and DC applications?

A: Yes. The Weidmüller 7940112057 is rated for 277V AC and 65V DC, matching the voltage specifications of the original SCHURTER part. It is suitable for both AC and DC circuit protection applications within these voltage ranges.