When choosing the product code for MCB (Miniature Circuit Breaker) and MCCB (Molded Case Circuit Breaker), you need to consider many factors to ensure that the product is suitable for your application, from performance requirements to performance to environmental conditions. Below is a detailed guide to help you choose the correct product code for both MCB and MCCB.
I. Instructions for choosing MCB product code
1. How to read parameters on MCB
Normally, on a CB, MCB, MCCB... there will be parameters for users to observe. We need to understand them so that we can more conveniently choose to buy and use them. Specifically, some parameters on MCB that you need to pay attention to are:
• MCB Current and Curve Rating: Usually this index will consist of a letter and a number, for example C20. The first letter represents the load characteristic curve. There are 3 load characteristic curves through letters: B, C and D. In this case, the MCB will be of type C. The number 20 represents the rated current with the unit of (A).
• MCB Operating Voltage: This parameter represents the operating voltage of the MCB with rated current. Normally, when used in a single-phase line, it will be 230V or 240V, and when used in a 3-phase line, it will be 400V or 415V.
• MCB Breaking Capacity: The limiting capacity of the fault current, usually expressed in numbers such as 10000, meaning 10kA or 10000A. This parameter will usually be chosen higher than what is likely to occur in the event of a failure.
• Energy Class: Limited energy level, based on this basic energy level, it is classified into classes such as: Class 1, Class 2, Class 3. Of which, Class 3 is the best level with a value of 1.5 LJ/s.
• MCB Status Indicator: Shows ON/OFF status during operation. A standard MCB device must have this parameter for easy operation or repair.
• Operation Symbol: Circuit diagram, showing the operating mechanism of MCB.
• Additional Relevant Information: Displays information about pulse voltage, ISI…
• Catalog No: This information helps users learn more about the product on the internet.
2. Things to note when choosing MCB
When choosing MCB, we need to pay attention to some parameters as follows:
• Determine the rated current of the MCB and the system to be protected:
This value must be lower than the current carrying capacity of the electrical system. Besides, it must be higher than or equal to the maximum load current in the system. Normally, choosing the MCB's rated current at 125% of the load current is appropriate.
• Fault current limited capacity:
MCB can interrupt circuit in short circuit condition. It is expressed in Kilo Amps (KA). This value must not be lower than the potential short-circuit current. Potential short circuit current is the maximum current that exists in a circuit under short circuit conditions. In civil use, this parameter averages about 6kA MCB which is enough. In industry, this parameter is usually chosen from 10kA or more.
• Load characteristic curve of MCB:
Based on each type of MCB that we have provided above, you can choose for yourself each type of MCB suitable for your intended use.
II. Instructions for choosing MCCB product code
1. How to read MCCB parameters
MCCB specifications for all products are basically the same, including:
• In: Rated current (also known as rated current), allowable limit of current. When the rated current exceeds the allowable value, it will cause fire, explosion and damage.
• Icu: Abbreviation for ultimate current, represents the CB contact's ability to withstand the maximum current for 1 second.
• Service Breaking capacity (%Icu): This MCCB parameter indicates the actual breaking capacity when a problem occurs. Depending on each device and each manufacturer
• Characteristic curve: This is the selectivity curve of MCCB.
• Mechanical/electrical endurance: Number of mechanical switching times allowed
• Icw (rated short-time) withstand current: Represents the MCCB's ability to withstand short-circuit current.
2. How to choose MCCB
Currently there are many ways to choose a suitable MCCB. However, no matter how you choose MCCB, you still need to satisfy these conditions:
• IB < In < IZ
• ISCB > ISC
In there:
• IB is the largest load current.
• In is the rated current of the MCCB.
• Iz is the maximum allowable current of the electrical conductor (specified by the manufacturer).
• The ISCB is the maximum current that the MCCB can cut.
• ISC is short circuit current.
Therefore, if based on the above conditions and parameters, choose the most suitable MCCB for the industrial power system. This will ensure safety and protect electrical equipment against unwanted incidents such as overload, short circuit or voltage drop of the electrical circuit.
III. Comparison between MCB and MCCB
MCB (Miniature Circuit Breaker) and MCCB (Molded Case Circuit Breaker) are two common overload and short circuit protection devices in electrical systems. Although both play an important role in ensuring the safety of electrical equipment, they have different characteristics and applications. Here are some key differences between MCB and MCCB:
Comparison basis | MCB | MCCB |
Define | The device protects the system from excessive current. | The device protects the system when current is overloaded like MCB but has an additional function of current correction in addition to protecting the device from excessive temperature and fault current. |
Abbreviations | Miniature circuit breaker | Molded circuit breakers |
Switches | Permanent | Fixed or movable |
Cutting ability | 1800 A | 10k – 200k |
Remote on/off | Can't | Can |
Rating Current | 100 amps | 10 – 200 amps |
Application | For low load systems | For systems with heavy loads |
Uses | Used in civil works | Commercial and industrial use |
Conclude
Choosing the appropriate MCB and MCCB model requires careful consideration of many factors from capacity, voltage, protection features, to environmental conditions and system scalability. By comprehensively considering the above factors, you can choose a product that not only meets current usage needs but also has the ability to develop and integrate in the future, optimizing costs and benefits. improve usage efficiency. Don't forget to take full advantage of support from manufacturers and suppliers to ensure you choose the best, most suitable product for your needs.
In case you need to learn, need technical advice and order MCB and MCCB, please contact Amazen immediately via:
Hotline: 0934 399 068 - Sales: 0938 072 058
Email: amazen@amazen.com.vn
With a team of highly specialized technical support and sales consultants, our company is confident that it will bring customers the best purchasing experience.
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