QDS28-S DC air circuit breaker

1. QDS DC air circuit breaker
2. □ - Design Number
3. □ - Rated working current
4. □ - Operation method (S-manual operation)
5. X-Product installation of protective box shell
6. □ - Rated working voltage (KV)

Structural characteristics of QDS28-S DC air circuit breaker:
1. Base and bracket: made of thermosetting engineering plastic compression, serving as mechanical support and electrical insulation, with excellent insulation performance;
2. Operating mechanism: composed of a rotating shaft, energy storage spring, transmission components, and mechanical lock buckle, the circuit is manually closed and locked through an operating handle. When overcurrent occurs, the transmission mechanism can be automatically disconnected through a trip, and under normal circumstances, manual quick disconnection can be achieved through the operating handle;
3. Dynamic and static contacts: Silver alloy contacts using DC contactors have characteristics such as resistance to welding and wear. The static contacts are connected to the arc blowing coil, while the dynamic contacts are connected to the lead out terminal through soft connections;
4. Arc extinguishing cover: composed of a maze type ceramic arc extinguishing chamber, large and small arc ignition angles, and an arc resistant plastic shell, it has excellent arc extinguishing effect and short arc spraying distance when the circuit breaker is disconnected;
5. Magnetic blowing coil: wound with silver plated flat copper wire, with a movable iron core at the center, which not only generates electromagnetic force for overcurrent tripping, but also provides a blowing magnetic field for the arc extinguishing chamber through a magnetic plate;
6. Tripping current adjustment mechanism: composed of components such as a crank, tension spring, indicator, locking screw, etc. The tripping current value can be adjusted by adjusting the screw, with clear scale indication and can be locked to prevent loosening;
7. Auxiliary contact: It has a pair of normally open and normally closed pure silver contacts, which can slide laterally at the moment of connection to ensure good contact;
8. Operating handle: With insulation protection function, it can be separated from the circuit breaker body and is a specialized operating tool.

Normal working and installation conditions:
1. The altitude shall not exceed 2500 meters;
2. The highest temperature of the surrounding air is+50 ℃, and the lowest is -40 ℃;
3. The maximum relative humidity of the surrounding air shall not exceed 90%;
4. Vibration intensity: For sinusoidal vibrations in any direction of longitudinal, transverse, or vertical, the amplitude shall not exceed A, and the value of A shall be determined by the following formula:
A=25/f, frequency f=1-10Hz
A=250/f2, frequency f=10-50Hz
5. In environments without explosion hazards, corrosive gases, and conductive dust.

Main technical parameters:

QDS28-S DC air circuit breaker