Description of the problem

Can the AC circuit breakers in the OSN3500 distribution box be used in DC powered scenarios?

The Solution

1, AC circuit breaker used in DC scenario analysis.

The main difference between AC current and DC current is that there is a zero crossing point in the AC system, breaking is relatively easy; while the DC system current does not cross the zero crossing point, fault current occurs when the contact and arc extinguishing system requirements are higher, breaking is relatively more difficult than the AC.

2, corresponding to DC application scenarios, the choice of circuit breaker is mainly based on the following three points.

a. Rated current depends on the load power.

b. The maximum short-circuit current at the point of installation determines the breaking capacity.

c. The rated voltage determines the number of series stages for breaking.

3. Therefore, if an AC circuit breaker is used in a DC scenario, it should be used at a reduced voltage while maintaining the same parameters such as life and breaking capacity.

Note: reduce the voltage how much, whether there is a reference value, not supported by the data so this paper does not do this part of the description.

According to the information provided by Liangxin (the supplier of DPD63-8-8 DC distribution box), the maximum voltage and breaking capacity of AC products used in DC are shown in the following table.

The breaking capacity of 10KA means that it can be used in the line with short-circuit current not more than 10KA, and so on; the parameter of keeping life is not reflected in the information of Liangxin manufacturer.

4、Obtain the DC certification report of the manufacturer (the certificate is attached).

DPD63-8-8 distribution box, adopts NDB2-63 series circuit breaker produced by Liangxin manufacturer. This series of circuit breakers are suitable for both AC and DC scenarios, and have obtained CE, TUV, UL and CCC certificates.

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