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Home Products Circuit Protection Circuit Breakers~~B21-B0-24-620-B1B-K3~~

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B21-B0-24-620-B1B-K3 - Carling Technologies

Manufacturer Part Number: B21-B0-24-620-B1B-K3

Manufacturer: Carling Technologies

Allelco Part Number: 98D-B21-B0-24-620-B1B-K3

Warranty: 1 Year Allelco Warranty - Find out more

Stock Status:: 44,809 pcs available, New & Original

Parts Description: CIRCUIT BREAKER

Package: Bulk

Data sheet: -

RoHs Status: ROHS3 Compliant

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In stock: 44809

Unit Price: $58.92
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Specifications

B21-B0-24-620-B1B-K3 Tech Specifications
Carling Technologies - B21-B0-24-620-B1B-K3 technical specifications, attributes, parameters and parts with similar specifications to Carling Technologies - B21-B0-24-620-B1B-K3

Product Attribute	Attribute Value
Manufacturer	Carling Technologies
Voltage Rating - DC	80 V
Voltage Rating - AC	120 V
Series	B
Package	Bulk
Number of Poles	1
Mounting Type	Panel Mount

Product Attribute	Attribute Value
Illumination Voltage (Nominal)	-
Illumination	None
Current Rating (Amps)	20A
Breaker Type	Magnetic (Hydraulic Delay)
Approval Agency	CCC, TUV, UL489
Actuator Type	Rocker

Environmental & Export Classifications

ATTRIBUTE	DESCRIPTION
RoHs Status	ROHS3 Compliant
REACH Status	REACH Unaffected
ECCN	EAR99
HTSUS	8536.20.0020

Frequently Asked Questions(FAQ)

What are the key electrical and mechanical constraints to consider when selecting the B21-B0-24-620-B1B-K3 for a 120 V AC industrial control panel application?: The B21-B0-24-620-B1B-K3 is rated for 20A at 120 V AC and 80 V DC, making it suitable for low-voltage AC control circuits commonly found in industrial panels. Its magnetic (hydraulic delay) trip mechanism provides moderate inrush tolerance, which is beneficial for inductive loads such as contactors or small motors. However, the single-pole configuration limits its use to line-neutral or single-phase circuits, and the 120 V AC voltage ceiling means it should not be applied in higher-voltage mains systems. Panel mounting requires a standard rocker cutout, and the absence of illumination simplifies integration but reduces visual status feedback.

How does the hydraulic delay characteristic of the B21-B0-24-620-B1B-K3 affect its response to short-duration overloads compared to a thermal-magnetic breaker?: The B21-B0-24-620-B1B-K3 uses a hydraulic delay mechanism that introduces a time-dependent trip response, allowing it to tolerate brief overloads (e.g., 1.5x to 5x rated current) for several seconds without nuisance tripping. This contrasts with purely thermal breakers, which respond more slowly to sustained overloads but lack precision in short-duration events. In applications with motor startups or transformer energization, this behavior can prevent unnecessary interruptions while still protecting against sustained faults above 20A.

Can the B21-B0-24-620-B1B-K3 be used in a 24 V DC system drawing 18A continuously, and what derating considerations apply?: Yes, the B21-B0-24-620-B1B-K3 is rated for 80 V DC and 20A, so a 24 V DC system at 18A falls well within its operational envelope. However, DC applications require careful consideration of arc interruption capability. While the breaker is approved for DC use, the absence of a DC-specific curve in typical documentation suggests reliance on general performance within the 80 V DC limit. For continuous operation at 18A (90% of rating), thermal management and ambient temperature should be monitored, as prolonged loading near maximum can affect hydraulic delay calibration.

What panel mounting specifications and environmental factors must be addressed when installing the B21-B0-24-620-B1B-K3 in an outdoor enclosure?: The B21-B0-24-620-B1B-K3 is designed for panel mounting with a standard rocker actuator interface, requiring a compatible cutout typically around 20.4 mm x 31.8 mm. When used in outdoor or high-humidity environments, the enclosure must provide adequate sealing (e.g., NEMA 3R or higher) to prevent moisture ingress, as the breaker itself is not sealed. Additionally, ambient temperatures outside the standard operating range (typically -20°C to +60°C for such devices) can alter the hydraulic delay timing, potentially leading to delayed tripping or reduced sensitivity.

How does the B21-B0-24-620-B1B-K3 compare to a solid-state circuit protector in terms of fault response time and longevity in a high-cycle automation system?: The B21-B0-24-620-B1B-K3, as a hydraulic-magnetic device, offers mechanical robustness and immunity to EMI, making it reliable in electrically noisy environments. However, its mechanical contacts are subject to wear over thousands of operations, unlike solid-state protectors that have no moving parts. In high-cycle applications (e.g., >10,000 operations), the B21-B0-24-620-B1B-K3 may exhibit contact degradation, whereas solid-state alternatives provide faster, repeatable trip responses but are more sensitive to voltage transients and require additional heat sinking.

Is the B21-B0-24-620-B1B-K3 suitable for protecting a 120 V AC solenoid valve bank with inrush currents up to 35A for 100 ms?: The B21-B0-24-620-B1B-K3 can likely tolerate this inrush due to its hydraulic delay design, which allows temporary overloads above 20A without immediate tripping. Based on typical hydraulic-magnetic curves, currents around 1.75x rated (35A) may take 0.1 to 2 seconds to trip, depending on exact calibration. For a 100 ms pulse, the breaker should remain closed, but cumulative cycling or elevated ambient temperatures could shift the trip threshold. Verification with manufacturer time-current curves or empirical testing is recommended for mission-critical systems.

What certification implications arise from using the B21-B0-24-620-B1B-K3 in equipment destined for both North American and European markets?: The B21-B0-24-620-B1B-K3 carries UL489, TUV, and CCC certifications, indicating compliance with North American (UL), European (TUV), and Chinese safety standards. This multi-certification simplifies global product deployment, particularly for industrial control gear exported to these regions. However, end-product certification (e.g., CE marking under LVD or UL listing for the complete assembly) still requires system-level evaluation, as the breaker’s approval does not automatically extend to the entire apparatus.

How should the B21-B0-24-620-B1B-K3 be coordinated with upstream fuses or breakers in a layered protection scheme?: In selective coordination, the B21-B0-24-620-B1B-K3 should trip before upstream devices during downstream faults to minimize system downtime. Its hydraulic delay allows it to ride through minor overloads, so upstream breakers or fuses must have sufficient time-delay characteristics to avoid premature operation. For example, a 30A upstream breaker with a thermal delay should not trip on a 25A overload that the B21-B0-24-620-B1B-K3 handles within its time-current band. Coordination studies using published curves are essential to ensure proper hierarchy.

What are the long-term reliability concerns with the B21-B0-24-620-B1B-K3 when used in high-vibration environments such as mobile machinery?: While the B21-B0-24-620-B1B-K3 is mechanically robust, sustained vibration can affect the hydraulic delay mechanism’s fluid dynamics and contact alignment over time. Panel mounting must include secure fastening to prevent loosening, and the rocker actuator should be protected from accidental actuation. In high-vibration settings, periodic inspection of trip performance and torque on mounting hardware is advisable to maintain consistent protection characteristics.

Can the B21-B0-24-620-B1B-K3 be paralleled with another identical unit to increase current capacity, and what risks does this introduce?: Paralleling the B21-B0-24-620-B1B-K3 with another unit is not recommended. Even with matched ratings, slight differences in trip calibration, contact resistance, or thermal conditions can lead to uneven current sharing. One breaker may carry more load and trip prematurely, defeating the purpose of paralleling and potentially causing cascading failure. For higher current needs, a single appropriately rated breaker should be selected instead.

How does the absence of illumination in the B21-B0-24-620-B1B-K3 impact maintenance and fault diagnosis in a distributed control system?: The non-illuminated rocker design of the B21-B0-24-620-B1B-K3 requires visual inspection of the actuator position (open/closed) to determine trip status, which can delay fault identification in hard-to-reach panels. In distributed systems, this increases reliance on remote monitoring or auxiliary contact modules. While the simplicity enhances reliability, it reduces diagnostic immediacy compared to illuminated or remotely signaled variants.

What derating is necessary for the B21-B0-24-620-B1B-K3 when installed in an enclosure with ambient temperatures reaching 55°C?: At 55°C ambient, the B21-B0-24-620-B1B-K3 may require current derating due to reduced heat dissipation and potential impact on the hydraulic fluid viscosity. While exact derating factors depend on Carling’s thermal curves, a common practice is to limit continuous current to 80–90% of rating (16–18A) at elevated temperatures. This ensures the breaker can still trip reliably under overload without premature aging of internal components.

How does the B21-B0-24-620-B1B-K3 perform in low-current fault conditions, such as a 22A overload sustained for 30 seconds?: At 22A (1.1x rated current), the B21-B0-24-620-B1B-K3 will likely not trip immediately due to its hydraulic delay mechanism, which is calibrated to ignore minor overloads. Depending on calibration, such a condition may persist for tens of seconds to several minutes before tripping. This behavior is intentional to avoid nuisance trips but means the breaker is not suitable for precise overcurrent protection near the rated threshold—thermal devices or electronic protectors may be more appropriate for such granular control.

What are the key differences between the B21-B0-24-620-B1B-K3 and a similarly rated thermal circuit breaker in terms of reset behavior and trip consistency?: The B21-B0-24-620-B1B-K3 provides consistent trip timing regardless of ambient temperature fluctuations, unlike thermal breakers whose response slows in cold environments. Additionally, it can be reset immediately after tripping, whereas thermal breakers often require a cooldown period. However, the B21-B0-24-620-B1B-K3’s hydraulic mechanism may exhibit slight hysteresis over repeated cycles, whereas thermal breakers reset predictably once cooled.

Is the B21-B0-24-620-B1B-K3 appropriate for protecting a battery-powered DC load in a portable medical device operating at 48 V and 15A?: The B21-B0-24-620-B1B-K3 is rated for 80 V DC and 20A, so electrically it can handle a 48 V, 15A load. However, medical devices often require higher reliability standards (e.g., IEC 60601), and the lack of medical-specific certification for this breaker may pose compliance challenges. Additionally, the rocker actuator may not meet ingress or actuation force requirements for medical enclosures. A medically approved alternative with equivalent ratings should be evaluated.

How does the B21-B0-24-620-B1B-K3 handle high-magnitude short-circuit currents, and what interrupting rating should be assumed?: While the datasheet specifies voltage and current ratings, the short-circuit interrupting capacity is not explicitly stated in the provided parameters. For UL489-listed breakers like the B21-B0-24-620-B1B-K3, typical interrupting ratings range from 1,000 to 10,000 A, but the exact value depends on the specific model and test conditions. Always consult the manufacturer’s interrupting rating documentation and ensure the available fault current at the point of installation does not exceed this limit.

What design practices ensure reliable operation of the B21-B0-24-620-B1B-K3 when used in a high-altitude application above 2,000 meters?: At altitudes above 2,000 meters, air density decreases, reducing arc quenching capability and potentially increasing contact wear during interruption. The B21-B0-24-620-B1B-K3 may require derating or enhanced spacing in the panel to maintain performance. Carling typically provides altitude derating guidelines; if not available, a conservative approach is to derate current by 1% per 100 meters above 2,000 m and ensure adequate ventilation to prevent thermal buildup.

Can the B21-B0-24-620-B1B-K3 be used in a three-phase system as a single-pole protective device for one phase?: Yes, the B21-B0-24-620-B1B-K3 can be used to protect a single phase in a three-phase system, provided the phase voltage does not exceed 120 V AC to ground. However, it only protects one conductor, so coordination with other phase protection devices is necessary. Care must be taken to ensure that a fault on one phase does not leave the system unbalanced or create hazardous conditions. This configuration is common in control circuits powered from one phase of a three-phase supply.

Parts with Similar Specifications

The three parts on the right have similar specifications to Carling Technologies B21-B0-24-620-B1B-K3

Product Attribute
Part Number	B21-B0-24-620-41E-K3	B21-B0-22-620-C1B-K3	B21-B0-24-620-21A-K3	B21-B0-24-620-11E-K3
Manufacturer	Carling Technologies	Carling Technologies	Carling Technologies	Carling Technologies
Illumination	-	-	-	-
Package	-	Tape & Reel (TR)	Tube	Tape & Reel (TR)
Approval Agency	-	-	-	-
Series	-	-	-	-
Number of Poles	-	-	-	-
Actuator Type	-	-	-	-
Voltage Rating - AC	-	-	-	-
Mounting Type	-	Surface Mount	Through Hole	Surface Mount
Breaker Type	-	-	-	-
Illumination Voltage (Nominal)	-	-	-	-
Current Rating (Amps)	-	-	-	-
Voltage Rating - DC	-	-	-	-

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Apr 17, 2026

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Mich***Smith

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Shipping was on time, the component pins are neatly aligned, and I tested 10 of them with a multimeter—all readings were within the specified range. Highly recommended.
Aman***arris

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It was great—the entire process, from placing the order to receiving the package, went very smoothly. The components were consistent, the price was fair, and I had a very pleasant shopping experience.
Mike***nch

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Daic***K.

Mar 23, 2026

Very good. No issue after long time testing.

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Common Countries Logistic Time Reference
Region	Country	Logistic Time(Day)
America	United States	5
America	Brazil	7
Europe	Germany	5
	United Kingdom	4
	Italy	5
Oceania	Australia	6
Oceania	New Zealand	5
Asia	India	4
Asia	Japan	4
Middle East	Israel	6

DHL & FedEx Shipment Charges Reference
Shipment charges(KG)	Reference DHL(USD$)
0.00kg-1.00kg	USD$30.00 - USD$60.00
1.00kg-2.00kg	USD$40.00 - USD$80.00
2.00kg-3.00kg	USD$50.00 - USD$100.00

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