Tag: circuit breaker

Isolators and Circuit Breakers both are electrical devices used to isolate a section of power system. But what are the differences between them? In this video we are gonna make clear the differences between Isolators and Circuit Breakers which are to be explained considering factors such as type of device and their action, operation of both appliances, their functions, withstand capability and applications, etc.

Both air circuit breaker (ACB) and molded case circuit breaker (MCCB) are used for the safe switching on and off of electrical systems. In principle, both serve the same purpose. The ACB is usually found on the upstream side of the circuit, while the MCCB is found on the load-side control (usually, the load-side switch operates more frequently than the upstream). These three protection devices are selected according to the required operating voltage and protection level (fault level) of the system. As technology continues to advance, the ratings and breaking capacities of MCCBs are increasing, so the applications of ACBs and MCCBs may overlap.

Traditional molded case circuit breakers use electromechanical (thermal-magnetic) trip units that can be fixed or interchangeable. MCCBs provide protection by combining temperature sensitive equipment with current sensitive electromagnetic equipment. Both devices act mechanically on the trip mechanism. In the use of molded case circuit breakers, various faults will be found, and frequent tripping of molded case circuit breakers is one of the common fault phenomena.

Vacuum circuit breakers are used for switching purposes in high voltage (HV) applications. Vacuum circuit breakers are more efficient, smaller and less expensive. Vacuum circuit breakers have a much longer lifespan than conventional circuit breakers and require little maintenance. Vacuum circuit breakers are ideal for typical utility and industrial applications.

Vacuum circuit breaker is an internal power distribution device in three-phase AC system with voltage of 3-10kV and frequency of 50Hz. In industrial and mining organizations, power plants and substations can be used to protect and control electrical equipment. The circuit breaker can be configured in the middle cabinet, double-layer cabinet and fixed cabinet to manage and protect the high-voltage electrical equipment in the maintenance and frequent operation area.

With new improvements in vacuum breaker design, vacuum circuit breakers are becoming more common at the lower voltage ranges of transmission networks. When choosing a vacuum circuit breaker, we need to consider many factors. But the most important thing is to know about vacuum circuit breakers before you can make a choice. The following brief introduction hopes to help you choose the right one.

The realization of the overload protection function of the miniature circuit breaker is based on the principle that bimetals bend in a regular direction as the temperature rises. After the miniature circuit breaker is closed, it is in normal working condition. The inner bimetal is heated by a certain current passing through it. The two pieces of metal have different thermal expansion coefficients and cause bending.

A circuit breaker is essentially a safety device for any property that uses electricity. These fixtures act as third parties in complex and dangerous electrical wiring systems. MCB and MCCB are circuit breakers. They are used in homes to prevent personal injury and electrical damage. These devices are designed to perform specific functions. It is their special features that make them special. So, what are the differences between them?

Vacuum contactor is a device that can withstand multiple operations (strong mechanical life). It can cut off the load current at the same time, but can not break the short-circuit current. The vacuum contactor has two contacts, normally open and normally closed, and does not have the function of short-circuit current protection. When a given signal is received, it can perform separation and hold actions. Analogus to ordinary home circuit, VCB is like a circuit breaker at home inside a panel and VC is a relay in our any of instruments at home.

Miniature circuit breaker, short for MCB, is one of the most widely used terminal protection appliances in building electrical terminal distribution devices. And this article shows the right selection of MCB based on its electrical parameters. The rated breaking capacity of MCB is the maximum short-circuit current value that can be broken without any damage to the circuit breaker. The miniature circuit breakers currently on the market generally have several rated breaking capacities, including 4.5kA, 6kA and 10kA according to the relevant technical data and design manuals provided by various manufacturers.

The advantages of indoor high voltage vacuum circuit breaker are not only oil-free equipment, but also long electrical life. It has mechanical life, large breaking insulation capacity, strong continuous breaking capacity, small volume, light weight, frequent operation, fire free, less operation and maintenance, etc. And they are quickly recognized by the operation, maintenance and technical personnel of the power department. The quality of some high voltage vacuum circuit breakers is not stable enough, the current carrying voltage is on the high side during operation and some vacuum interrupters still have air leakage. With the wide application of vacuum circuit breaker, faults also occur from time to time. The author analyzes the common faults of vacuum circuit breaker and gives treatment methods.

Safety switch is a switch that prevents people from entering a dangerous area before all safety conditions are met. Also it is a device that monitors current in various applications. Safety switches can be used in major equipment applications (conveyor belts, production line equipment, heavy equipment) and electrical protection of whole system. The safety switch works by monitoring the current and detecting electrical faults, which means that in case of leakage, short circuit, overload, the safety switch will cut off the power supply of the faulty system almost immediately (within a few milliseconds).

ATO miniature circuit breaker is mainly used for AC 50Hz or 60Hz, voltage ratings 230/400V, 240/415V and 277/480V, and current ratings from 1A to 63A. The miniature circuit breaker is characterized with compact structure, reliable performance, strong breaking capacity and beautiful appearance. It can be applied for overloading and short-circuit protection of lighting, distribution lines and equipment of office buildings, houses and similar buildings. The mini circuit breaker is also used for not frequently on-off operations and conversions on the lines.

1P, 2P, 1P+N, 3P, 4P, 4P+N, P means that the miniature circuit breaker (MCB) is equipped with a protective pole (knife pole), N means that the neutral conductor is only equipped with knife pole, but no protection modules. Both 2P and 1P+N are called two pole switch, 4P and 3P+N are called 4 pole switch. Neutral conductor of 1P+N and 3P+N don't have protection, so they are much cheaper, the neutral conductor pole acts along with the phase line pole. Some circuit breakers divide 1P+N into two types: one adopts two module width, another adopts one module width (small size). For these poles, how to select a right miniature circuit breaker?

Whether low-voltage circuit breakers are installed properly, which will directly affect its performance and safety. Generally pay attention as follows:

1. Before installation, the technical parameters listed on the nameplate of the low-voltage circuit breaker should be checked for compliance with the requirements.
2. Low voltage circuit breakers should be installed vertically, and the wired in front of the board are allowed to be mounted on metal brackets or metal backplanes, but the low-voltage circuit breakers that are wired behind the board must be mounted on the insulating base plate. The bracket or bottom plate of the fixed low-voltage circuit breaker must be flat to prevent damage to the insulating base when the screws are tightened. In order to prevent accidents caused by arcing, the copper busbar of the low-voltage circuit breaker should be packed with 200mm insulation or phase-interval arc plate from the insulation base.

Circuit breakers and fuses can protect the electric equipment and lines from short circuit. Actually, both have their own characteristics. Circuit breakers are used to switch on and off the load circuit as well as cut off the fault circuit, so as to ensure the safety. The fuse is used as a protector by melting itself when the current is too high or exceeds the load current. It is completely different from the circuit breaker on the breaking current. Its function can be easily understood by the commonly used fuse in our home.