DC Fast Breaker

Product overview
WLDS1 (formerly DS16) and QDS8 series DC fast circuit breakers are suitable for DC circuits with rated voltage DC2000V and below and rated current 4000A and below. They are used in subway, light rail, tram, industrial and mining electric locomotive traction power supply system, steel rolling, mining and other industries to protect DC power supply and distribution system lines and equipment from short circuit and overload damage.
The series DC fast circuit breaker structure is single pole, non-polar. Its remarkable feature is the module structure, mainly including contact circuit, closing and holding device, direct overcurrent instantaneous release, arc extinguishing cover and auxiliary contact, etc.
The closing and holding device of the circuit breaker adopts a solenoid electromagnet, which makes the coil powered by the closing instruction. The moving iron core drives the moving contact and the static contact to close through the fork rod, and automatically connects the economic resistance after a delay of about 0.5S, and the iron core and the moving contact are kept in the closed position. Through the opening command, the coil is de-energized, the recovery spring forces the iron core and fork rod to reset, and the moving contact is disconnected.
When the load is overloaded or short-circuited, the flowing current is greater than the static setting value, the tripping moving iron core acts, driving the tripping rod to act, forcing the fork rod to release the moving contact upward to disconnect, and the arc current generated by the opening of the moving contact blows the arc into the arc extinguishing chamber due to the effect of the magnetic field of the main circuit itself.

Product Features
The product is a single-pole, non-polar circuit breaker, simple structure, simple maintenance.
It is mainly composed of contact circuit, closing and holding device, overcurrent instantaneous release, arc extinguishing cover and auxiliary contact.

High breaking capacity
At DC2000V operating voltages:
The limit breaking current of QDS8-1250 series fast circuit breaker is 30kA.
The limit breaking current of WLDS1-4000 series fast circuit breaker is 80kA.
The high breaking capacity reduces the maintenance workload of the contacts and greatly improves the electrical life of the fast circuit breaker.

Small arcing distance, small size
QDS8-1250 series fast circuit breakers are side flashover, with a maximum safety distance of 350mm (90mm with insulated walls).
The WLDS1-4000 series fast circuit breaker is an upper end flashover, and the maximum safety distance is 750mm (400mm with insulated wall).
The small size and arcing distance provide conditions for compact installation in the cabinet (box), especially on electric locomotives.