◆MCB circuit breaker
MCB is a miniature circuit breaker, also known as a conductor protection switch. It is a terminal protection device suitable for short circuit and overload protection of single-phase and three-phase low-voltage below 125A. It is mainly used to protect wires, cables and control lighting. It has a compact structure and its basic form is a sheet-shaped single-pole product with a width of less than 20mm. Two or more single-pole products can be assembled together to form a two-, three-, or four-pole circuit breaker. Miniature circuit breakers have thermal and electromagnetic tripping, overload and short-circuit protection functions, and are widely used in high-rise buildings and civil fields.
◆MCCB circuit breaker
MCCB is a plastic case circuit breaker, also known as a molded case switch. It is a low-voltage protective device that can automatically cut off the circuit when a short circuit, overload, undervoltage or other abnormal conditions occur in the circuit. It can also be used to start the motor infrequently. The ICCB current range is 100A~1600A. The breaking current is smaller than that of the frame circuit breaker and larger than that of the miniature circuit breaker. It has been widely used because of its safe operation, high breaking capacity, adjustable action value, multiple protection functions, and generally no need to replace parts after action.
◆ACB circuit breaker
ACB is a frame-type circuit breaker, also known as an open type or universal circuit breaker. All its components such as contact system, tripper, and protection device are installed in an insulated metal frame. It is characterized by large capacity, high ultimate short-circuit breaking capacity, high short-time withstand current, good selectivity and stability. Its rated current is generally between 200-4000A, and it is mainly used as the main switch of the low-voltage power distribution system to close and protect the incoming line, busbar and other important main line current circuits with large loads.
◆VCB circuit breaker
VCB is a vacuum circuit breaker, named because its arc extinguishing medium and the insulating medium between the contacts after arc extinguishing are both high vacuum. It has the advantages of small contact opening distance, short arc burning time, fast recovery speed of the contact gap medium after arc extinguishing, small size, light weight, long life, can be used for frequent operation, and arc extinguishing does not require maintenance. Its rated current is 5000A and its breaking current can reach 50kA. It is suitable for controlling and protecting high-voltage electrical equipment in 3~35kV distribution networks, especially for places requiring oil-free operation, less maintenance and frequent operation.
◆RCCB circuit breaker
RCCB is a residual current operated circuit breaker with leakage protection and short circuit protection functions, without overcurrent protection function, that is, leakage switch. Its main function is to protect people from electric shock. When RCCB detects some current flowing through the human body due to electric shock, or detects some electrical errors (such as short circuit, insulation fault or equipment failure), it will be triggered immediately and tripped in time. The tripper disconnects the main contacts of the main circuit, thereby playing a protective role. !RCCB circuit breaker has two functions: leakage protection and short circuit protection.
◆RCBO circuit breaker
RCBO is a leakage protection circuit breaker, which is an electromagnetic residual current operated circuit breaker with overcurrent protection. RCBO can prevent fire and explosion accidents caused by human electric shock or leakage in low-voltage lines. It is mainly used in places where overcurrent protection (overload and short circuit) and ground fault current protection functions are required at the same time. It can detect faults and trip in time to ensure the safety of staff and equipment. Compared with other circuit breakers, RCB0 has very comprehensive functions, including short circuit protection, overload protection and leakage protection.
Summary
| Type | Protection function | Rated current | Breaking capacity | Typical application |
|---|---|---|---|---|
| MCB | Overload, short circuit | ≤125A | 6kA–10kA | Domestic branch circuits |
| MCCB | Overload, short circuit (extendable ground fault) | 10A–2500A | 10kA–100kA | Industrial Distribution |
| ACB | Overload, short circuit | 630A–6300A | >100kA | Main distribution systems |
| VCB | Overload, short circuit (medium and high voltage) | 1kV–36kV | extremely high | Substations, medium and high voltage systems |
| RCCB | Leakage | Use with MCB/MCCB | - | Protection against electric shock (e.g. bathrooms, kitchens) |
| RCBO | Leakage + overload + short circuit | ≤125A | 6kA–10kA | Household critical circuits (e.g. air conditioning, sockets) |
MCB, MCCB, ACB, and VCB circuit breakers all have short-circuit and overload protection functions, but no leakage protection function. MCCB and ACB circuit breakers are both low-voltage circuit breakers. MCB circuit breakers have a small breaking current; MCCB circuit breakers have a medium breaking current; ACB circuit breakers have a large breaking current. VCB circuit breakers are generally high-voltage circuit breakers, and the breaking current is very large. RCCB and RCBO circuit breakers all have leakage protection functions. RCCB circuit breakers have short-circuit protection functions, but no overcurrent protection functions; RCB0 circuit breakers have short-circuit protection functions and overcurrent protection functions.
If you want to know more about circuit breaker or buy these devices,please reach out us at:pannie@hdswitchgear.com.
