CMB-203-11C3N-B-A Thermal Circuit Breaker Equivalent & Substitute Parts

Part Overview

The CMB-203-11C3N-B-A is a single-pole thermal circuit breaker manufactured by Carling Technologies, rated for 20A at 250V AC and 32V DC. This panel-mount component features push-to-reset actuation and is designed for overcurrent protection in industrial and commercial applications. The part maintains active product status with ROHS3 compliance and carries multiple approval agencies including CE, cUL, TUV, UL1077, and UL1500. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and supply chain continuity.

Substiute Parts

CMB-203-11C3N-B-A

Carling TechnologiesIn Stock: 1132CMB-203-11C3N-B-A Datasheet

Current PartRFQ

W57-XB7A4A10-20

TE Connectivity Potter & Brumfield RelaysIn Stock: 10457W57-XB7A4A10-20 Datasheet

DirectRFQ

W58-XB1A4A-3

TE Connectivity Potter & Brumfield RelaysIn Stock: 3619W58-XB1A4A-3 Datasheet

DirectRFQ

QLB-203-00DNN-3BA

QualtekIn Stock: 1584QLB-203-00DNN-3BA Datasheet

Parametric EquivalentRFQ

QLB-203-11B3N-3BA

QualtekIn Stock: 3150QLB-203-11B3N-3BA Datasheet

Parametric EquivalentRFQ

QMB-203-00ENN-3BA

QualtekIn Stock: 1415QMB-203-00ENN-3BA Datasheet

Parametric EquivalentRFQ

QMB-203-11C3N-3BA

Qualtek Electronics Corp.In Stock: 1884QMB-203-11C3N-3BA Datasheet

Parametric EquivalentRFQ

W28-XQ1A-20

TE Connectivity Potter & Brumfield RelaysIn Stock: 3137W28-XQ1A-20 Datasheet

Parametric EquivalentRFQ

W28-XT1A-20

TE Connectivity Potter & Brumfield RelaysIn Stock: 1404W28-XT1A-20 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts are classified into two categories based on electrical and mechanical parameter alignment:

Direct Manufacturer Substitutes maintain identical or functionally equivalent electrical specifications (20A, 250V AC, push-to-reset, single-pole, panel mount) but may originate from different manufacturers or series lines. These parts satisfy the core functional requirements without parameter deviation.

Parametric Equivalents match all critical electrical parameters (20A, 250V AC, 32V DC, push-to-reset, single-pole, panel mount) and are suitable for direct replacement in applications where the original part is unavailable. These parts are sourced from alternative manufacturers including TE Connectivity Potter & Brumfield Relays, Qualtek, and Qualtek Electronics Corp.

Key substitution criteria:

• Current Rating: 20A (mandatory match)
• Voltage Rating - AC: 250V (mandatory match)
• Voltage Rating - DC: 32V (mandatory match for parametric equivalents)
• Actuator Type: Push to Reset (mandatory match)
• Number of Poles: 1 (mandatory match)
• Mounting Type: Panel Mount (mandatory match)
• Breaker Type: Thermal (mandatory match)

Parameter Comparison

Engineering Selection Recommendations

Full Parameter Match (Recommended for Direct Replacement): QLB-203-00DNN-3BA, QLB-203-11B3N-3BA, QMB-203-00ENN-3BA, QMB-203-11C3N-3BA, W28-XQ1A-20, and W28-XT1A-20 provide complete electrical and mechanical equivalence to the CMB-203-11C3N-B-A. All candidates maintain 20A current rating, 250V AC, 32V DC voltage specifications, push-to-reset actuation, and panel-mount configuration. All substitute parts carry ROHS3 compliance and active product status.

Compliance Considerations: The original CMB-203-11C3N-B-A carries approval from CE, cUL, TUV, UL1077, and UL1500. Qualtek-manufactured substitutes (QLB and QMB series) carry TUV approval. TE Connectivity W28 series parts do not list specific approval agencies in provided data. Applications requiring specific regulatory certifications should confirm approval alignment with system requirements.

Packaging and Inventory: Bulk packaging is available across all parametric equivalents. Tray packaging is available for W57-XB7A4A10-20 only. Inventory levels vary; TE Connectivity W57-XB7A4A10-20 offers the highest stock position at 10,441 pieces.

Non-Equivalent Part: W58-XB1A4A-3 is not suitable for direct replacement. This part deviates from the 20A current rating specification (rated 3A) and 32V DC voltage specification (rated 50V DC), making it functionally incompatible with applications designed for the CMB-203-11C3N-B-A.

Frequently Asked Questions (FAQ)

Q: Can W57-XB7A4A10-20 replace CMB-203-11C3N-B-A? A: W57-XB7A4A10-20 matches the 20A current rating and 250V AC voltage specification with identical push-to-reset actuation and panel-mount configuration. However, DC voltage rating is not specified in available data. Confirm DC voltage compatibility with application requirements before substitution.

Q: What is the difference between QLB and QMB series substitutes? A: Both QLB-203 and QMB-203 series parts provide identical electrical specifications (20A, 250V AC, 32V DC) and mechanical configuration. Selection between series may be based on packaging availability, inventory levels, or specific application requirements. Both carry ROHS3 compliance and TUV approval.

Q: Why is W58-XB1A4A-3 listed but not recommended? A: W58-XB1A4A-3 is not a suitable substitute. The part is rated for 3A current (not 20A) and 50V DC (not 32V DC). These parameter deviations make it functionally incompatible with the original specification.

Q: Are all substitute parts ROHS3 compliant? A: All substitute parts listed in the parameter comparison table carry ROHS3 compliance status, matching the original CMB-203-11C3N-B-A specification.

Q: What packaging options are available? A: Bulk packaging is standard across all parametric equivalents. W57-XB7A4A10-20 is available in tray packaging. Packaging selection should align with procurement and assembly process requirements.

Q: Do all substitutes carry the same regulatory approvals as the original part? A: No. The original CMB-203-11C3N-B-A carries CE, cUL, TUV, UL1077, and UL1500 approvals. Qualtek substitutes carry TUV approval. TE Connectivity W28 series approval data is not provided. Applications with specific regulatory requirements should confirm approval alignment before substitution.