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CMB-203-27G3N-B-A Circuit Breaker Equivalent & Substitute Parts
Part Overview
The CMB-203-27G3N-B-A is a thermal circuit breaker manufactured by Carling Technologies, rated for 20A at 250V AC and 32V DC. This single-pole, panel-mount device features push-to-reset actuation and holds Active product status. The breaker is designed for overcurrent protection in AC and DC applications requiring thermal response characteristics.
Substitute parts are identified when equivalent electrical and mechanical parameters are maintained across manufacturers. The CMB-203-27G3N-B-A has documented substitute options from OptiFuse within the CBW57 series, which share identical current ratings, voltage specifications, mounting configuration, and actuation method.
Substiute Parts
Key Parameters
| Parameter | Value |
|---|---|
| Breaker Type | Thermal |
| Current Rating | 20A |
| Voltage Rating - AC | 250V |
| Voltage Rating - DC | 32V (Main Part) / 50V (Substitutes) |
| Mounting Type | Panel Mount |
| Actuator Type | Push to Reset |
| Number of Poles | 1 |
| Illumination | None |
| RoHS Status | ROHS3 Compliant |
Substitute Part Grouping Explanation
Substitution eligibility for the CMB-203-27G3N-B-A is determined by the following critical parameters:
Mandatory Matching Parameters:
- Current Rating: 20A
- Voltage Rating - AC: 250V
- Mounting Type: Panel Mount
- Actuator Type: Push to Reset
- Number of Poles: 1
- Breaker Type: Thermal
Allowable Variance:
- Voltage Rating - DC: The main part specifies 32V DC. All identified OptiFuse CBW57 series substitutes operate at 50V DC, which represents a higher voltage capability and is functionally compatible for applications rated at or below 32V DC.
All substitute parts listed maintain identical current handling, AC voltage rating, mechanical mounting, and reset mechanism. The DC voltage rating increase in substitute parts does not restrict their use in 32V DC applications, as the higher rating indicates greater voltage withstand capability.
Parameter Comparison
| Parameter | CMB-203-27G3N-B-A (Carling) | CBW57-EJ-20A (OptiFuse) | CBW57-EL4-20A (OptiFuse) | CBW57-ES-20A (OptiFuse) | CBW57-ES-20A-5H (OptiFuse) | CBW57-ES-20A-5X (OptiFuse) | CBW57-HS-20A-5X (OptiFuse) | CBW57-HS-20A-C (OptiFuse) | CBW57-PB-20A-WX (OptiFuse) | CBW57-PF-20A-5X (OptiFuse) | CBW57-PL-20A-5X (OptiFuse) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Breaker Type | Thermal | Thermal | Thermal | Thermal | Thermal | Thermal | Thermal | Thermal | Thermal | Thermal | Thermal |
| Current Rating (Amps) | 20A | 20A | 20A | 20A | 20A | 20A | 20A | 20A | 20A | 20A | 20A |
| Voltage Rating - AC | 250V | 250V | 250V | 250V | 250V | 250V | 250V | 250V | 250V | 250V | 250V |
| Voltage Rating - DC | 32V | 50V | 50V | 50V | 50V | 50V | 50V | 50V | 50V | 50V | 50V |
| Mounting Type | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount | Panel Mount |
| Actuator Type | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset | Push to Reset |
| Number of Poles | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| RoHS Status | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant |
| Product Status | Active | Active | Active | Active | Active | Active | Active | Active | Active | Active | Active |
Engineering Selection Recommendations
All listed OptiFuse CBW57 series circuit breakers are direct functional equivalents to the CMB-203-27G3N-B-A based on electrical and mechanical parameter alignment. Selection among substitute options is determined by:
Compliance and Certification: The CMB-203-27G3N-B-A carries approvals from CE, cUL, TUV, UL1077, and UL1500. OptiFuse CBW57 series substitutes carry cURus, IP 40, SAE J1171, UL 1077, and UL 1500 certifications. Both product lines maintain UL1077 and UL1500 compliance, satisfying standard thermal circuit breaker requirements.
Product Availability: All substitute parts maintain Active product status with documented inventory levels. Selection can be based on supply availability and lead time requirements specific to the application timeline.
Voltage Capability: The 50V DC rating of OptiFuse substitutes exceeds the 32V DC specification of the main part. This higher rating is compatible with all applications designed for 32V DC operation and provides additional margin for voltage transient conditions.
Packaging and Moisture Sensitivity: All OptiFuse CBW57 variants specify Moisture Sensitivity Level (MSL) 1 (Unlimited), indicating no moisture-related handling restrictions during storage or assembly.
Frequently Asked Questions (FAQ)
Q: Can OptiFuse CBW57 series breakers directly replace the CMB-203-27G3N-B-A?
A: Yes. All listed OptiFuse CBW57 variants maintain identical current rating (20A), AC voltage rating (250V), mounting configuration (panel mount), actuation method (push to reset), and pole count (1). The 50V DC rating of OptiFuse parts exceeds the 32V DC specification and is compatible with 32V DC applications.
Q: What is the significance of the different part number suffixes in the CBW57 series (EJ, EL4, ES, HS, PB, PF, PL)?
A: The suffixes denote internal design variations within the CBW57 series. All variants listed share identical electrical specifications (20A, 250V AC, 50V DC) and mechanical characteristics (panel mount, push to reset, single pole). Suffix differences reflect manufacturing or connector variations that do not affect functional equivalence for the specified electrical parameters.
Q: Are there any restrictions on using a 50V DC rated breaker in a 32V DC circuit?
A: No. A higher voltage rating indicates greater voltage withstand capability. A 50V DC rated breaker operates safely in 32V DC applications and provides additional margin against voltage transients or overvoltage conditions.
Q: Do all substitute parts carry the same regulatory approvals as the CMB-203-27G3N-B-A?
A: Both the main part and all substitutes carry UL1077 and UL1500 certifications, which are the primary standards for thermal circuit breakers. The CMB-203-27G3N-B-A includes CE and TUV approvals, while OptiFuse CBW57 variants include cURus and SAE J1171 approvals. Application requirements determine which certifications are necessary for specific end-use markets.
Q: Is RoHS compliance maintained across all parts?
A: Yes. The CMB-203-27G3N-B-A and all listed OptiFuse CBW57 substitutes are ROHS3 compliant. REACH status is either Unaffected or not specified, indicating no REACH substance restrictions.
Q: What inventory levels are available for each substitute part?
A: Inventory varies by part number. CBW57-ES-20A-5H has the highest documented stock at 2,458 pieces. CBW57-PL-20A-5X has the lowest at 862 pieces. All parts are listed as New Original In Stock. Specific availability should be confirmed at time of procurement.
Q: Can these breakers be used interchangeably in existing designs without modification?
A: Yes, for applications designed for the CMB-203-27G3N-B-A. All substitute parts maintain identical panel-mount mechanical configuration, push-to-reset actuation, and single-pole design. No circuit board modifications or mechanical redesign is required.
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