Circuit breaker housing rating
2020-03-28 1570The rated current of the circuit breaker frame level refers to the rated current of the * large release that can be installed in frames and plastic shells of the same basic size.
The rated current of a circuit breaker refers to the current that the release device in the circuit breaker can pass through for a long time, also known as the rated current of the circuit breaker release device.
There are multiple rated currents in the same series for the same frame level, and there are also multiple rated currents in the same frame level. For example, in the DZ20 series, there are rated currents of 100, 225, 400, 630, 800, 1250 and other frame levels, while in the 100 frame level rated currents, there are rated currents of 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A, and 100A; The rated current of the 225A shell frame level includes 100A, 125A, 160A, 180A, 200A, and 225A. Both the DZ20-100 and DZ20-225 housing levels have a rated current of 100A, but the volume, shape, and breaking capacity of the circuit breaker are different. Therefore, when selecting, the model number should be filled in completely, which is the rated current of the circuit breaker within the specific housing level rated current. The rated current classification is selected based on a priority coefficient of (1.25): on the one hand, it meets the needs of the rated current of * large lines and electrical components; On the other hand, it is for standardization to achieve optimal efficiency in using wires and processing. Therefore, the levels specified are: 3 (6), 8, 10, 12.5, 16, 20, 25, 32, 40, 50, 63, 80100, 125, 160, 200, 250, 315, 400A, etc. Due to this regulation, when the calculated load of the line is 90A, only the 100A specification can be selected, which to some extent affects its protection performance.
The current setting value of the release refers to the adjustment of the release to the operating current value. It refers to the multiple of the rated current In, which is the operating current value. For example, if the overcurrent is set to 1.2, 1.3, 5, or 10 times the current, it is written as Ir=1.2In, 1.3In, 5In, 10In, etc. Nowadays, some electronic release devices have adjustable overload and long delay rated current, and the adjusted current is actually still the rated current, which can be passed through for a long time.
The rated working current is the actual working current of the circuit breaker when installing auxiliary contacts (accessories) at a certain working voltage, with a current of 3A or 6A, used for controlling and protecting the circuit.
The previous article recommended information on the classification and model naming of molded case circuit breakers. Starting from this, we can learn that common molded case circuit breakers have certain differences in their names and classifications based on brand technology scale. Moreover, we have provided the models corresponding to three well-known brands, and also pointed out the areas that should be emphasized in the procurement process. For example, based on their different rated current and voltage, the scenarios they can be used may also be different, and the corresponding safety guarantee coefficients may vary greatly. You can learn more about the specific situation, or you can learn from the previous article comprehensively.
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