The DC system of the substation provides power for relay protection, automatic safety devices, control signal circuits, emergency lighting, etc. This is the basic guarantee for the correct operation of relay protection, automatic devices, and circuit breakers. Currently, circuit breakers and fuses are the main protection devices widely used in the substation DC system. When a circuit fault occurs, the faulty circuit can be selectively disconnected to limit the system fault to a very Miniature range. Circuit breakers and fuses usually need to be used in series. Selective protection between upper and lower levels is an important condition to ensure the safe and reliable operation of the power system.

EDB1-6311
Non-polarized Miniature DC circuit breakers have outstanding current limiting performance and strong breaking capability, accurately protecting relay protection and automatic devices from overloads, short circuits, and other fault hazards. Based on the advantages of the DC circuit breaker’s current limiting and arc extinguishing capabilities, comprehensive scientific experiments can achieve comprehensive protection of the main (auxiliary) screen, protection screen, and relay panel of DC systems below 3000ah.
Non-polarized Miniature DC circuit breakers have reversible protection, no positive or negative poles, can be connected up and down, avoiding serious circuit breaker burns due to wiring errors and serious accidents causing DC panel fires.

Onccy non-polarized DC micro circuit breakers, according to their use range, are divided into the EDB1-63 series high-voltage micro circuit breakers (for industrial and commercial energy storage) and the EDB1-125 series low-voltage micro circuit breakers (for household energy storage). In terms of parameters, some manufacturers have high breaking capacities, but the voltage can only reach 360V; some manufacturers can achieve very high voltages, but the rated current can only reach 40A, with a breaking capacity of only 1.5kA.

EDB1-125 DC MCB
The type of micro circuit breaker can be integrated into energy storage inverters, AC-coupled inverters, off-grid inverters, charging piles, battery packs, interrupting fault currents and thus ensuring the safety of the battery system; it can also be installed in switch boxes with a protection level up to IP66 as external protection. In addition to its outstanding non-polar performance, this micro circuit breaker also has short circuit protection, overload protection functions, high breaking capacity, has scientific arc extinguishing, current limiting, and trip mechanisms, can quickly disconnect the DC side’s fault current, ensuring the reliable operation of the DC system, perfectly matching photovoltaic, energy storage, and other DC systems. Additionally, by increasing the size of the moving contact, the electrical life of the product is enhanced (1000 times); the personalized handle design, using two steel pins to enhance mechanical strength, and surface plastic textures to increase friction, facilitates handle toggling for customers and guides them to center the handle, avoiding slipping, ensuring a mechanical life of up to 20,000,000 times.

DC MCB
With the increasing application of energy storage systems, ONCCY actively communicates with authoritative certification bodies such as Germany’s TUV Rheinland to keep abreast of industry dynamics. Currently, this DC micro circuit breaker has successfully passed TUV certification, EU CE certification, IECEE-CB certification, Australian SAA certification, and is actively participating in new energy exhibitions, selling well in domestic and foreign markets.”