The difference between MCB/MCCB/ACB/RCD/RCCB/RCBO
RCD: Residual current device (Residual current device), a general term for all leakage protection.
RCCB: Residual current circuit breaker, no overcurrent protection function.
RCBO: Residual Current Circuit Breaker with Overcurrent Protection, RCBO is a set of functions of RCD/RCCB, MCB, with overcurrent protection and leakage current action.
1. The breaking capacity of ACB is different. The breaking capacity of ACB is relatively high, followed by MCCB, and MCB is the worst. Of course, there are many MCCBs.
Manufacturers can achieve a high breaking capacity of MCCB, but the stability and reliability are not good;
2. The installation location is different, ACB is mostly used as the main circuit breaker, because it has a delay function, can delay breaking and tripping, and also has good communication function and selectivity, and MCCB is mostly used as The power distribution appliance is located in the middle of the line, because it only has the breaking capacity and inverse time tripping capacity, and it does not have selectivity. It can only be used as the lower-level protection switch, the emergency stop switch HW; MCB is mostly used on the load side, because Its breaking capacity is relatively low half of 6000A and 4500A;
3. The external dimensions are also very different. The MCB is small in size and easy to install. The ACB is the largest in size and the installation is complicated. The MCCB is in the middle.
How to ensure the safe use of circuit breakers
1. Focus on science and do a good job in product selection. The adaptive working conditions of the circuit breaker are the conclusions drawn after pre-consideration measures have been taken during product development, and then verified by actual working conditions. The selection of new or replacement products must be According to the actual requirements of the use site; after checking the test report for verification of the conditions, it is proved that the required functions are indeed available. When reviewing the test report, you must be careful to prevent it from being worn out. For example, the interception level of the new and old vacuum circuit breakers is very different , The old product is about 20-40A, and the new product with good performance can reach below 10A, and the overvoltage level generated during operation is also completely different.
2. Carefully manage the entire process of equipment. From selection, manufacturing quality, installation and acceptance, operation and maintenance, overhaul and testing, etc., all links must be conscientious. For products that have a large impact on problems and operations, they should also be in the manufacturing process. The destination participates in production supervision and eliminates congenital defects before formal production. After production, maintenance and overhaul are carried out regularly according to regulations, so that high-voltage switchgear can always maintain the performance required by technical conditions, and ensure that it is reliable and flexible at any time action.
3. Face up to the remaining problems in manufacturing and installation, and actively take corrective measures. When manufacturing or installing, as long as the existing problems are discovered, they should not be easily let go, let alone wait. Active measures should be taken, major problems, and even search for The manufacturer conducts research, and can't wait for an accident to take measures.
4. Be sure to treat all abnormalities that occur during the operation of switchgear correctly. In terms of safety management, attention should be paid to operation analysis, and first of all, unsafe signs should be grasped; abnormalities, obstacles and accidents must be carefully and thoroughly identified. Take preventive measures.
5. Seriously implement and implement anti-accident technical measures. The anti-accident technical measures are summarized from the accident lessons over the years, and a large amount of tuition has been paid, and the mistakes of past accidents cannot be repeated.