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You are here: Home > News > What is the difference between a DC breaker and an AC breaker ?

What is the difference between a DC breaker and an AC breaker ?

Date: 2019-05-03 Click: 499

Basic understanding of DC circuit breakers: Refers to circuit breakers used for DC shunt operation method conversion or fault removal. It can be used in industries such as electric power, post and telecommunications, transportation, industrial and mining enterprises, etc. for the equipment and electrical stop overload and short circuit maintenance of DC power distribution.
The operating principle of the DC circuit breaker: The main circuit of the DC circuit breaker includes a lower connection row supporting the movable contact, an upper connection row and a silver-plated contact on the outside, and a large can-shaped magnet with a closing coil is mounted on the closing Composition. The magnet contains a moving core, a contact pressure spring and a core return spring; all of these components are mounted on the operating rod. The fork unit is attached to the top of the lever. The overcurrent trip installation includes an armature consisting of laminated sheets, a moving core attached to a lever that is held by a spring, because the effect of the rod can set the trip setting. The five pairs of auxiliary contacts are the reversing contacts mastered by the moving contacts. They are located in the plastic box at the bottom of the closing installation. The arc extinguishing chamber comprises gussets, partitions and deionization plates, all of which are arranged between the two arc extinguishing plates. When the circuit breaker is opened due to overcurrent or normal opening and closing, the pushing mechanism will drive the moving contact to open. The pushing mechanism is different from the five commutating auxiliary contacts.
Two major categories of DC circuit breakers:
1. Two-stage DC circuit breaker. The two-stage DC circuit breaker has 8 to 10 times of the extra current of the lower-level switch and 4 to 5 steps of the differential operation. The accurate measures are superior to the joint venture.
2. Three-section DC circuit breaker. Three-stage DC circuit breaker, the lower stage is three-stage, the lower stage is two-stage or three-stage DC circuit breaker, the step difference is 2, and the short-circuit current is 25 to 40 times of the extra current of the lower-level circuit breaker. .
The main difference between DC circuit breaker and AC circuit breaker: the difference between the two is to eliminate arcing. Since the exchange has a zero crossing every cycle, the arc is easily extinguished at the zero crossing, and the DC switch has no zero crossing, and the arc extinguishing ability is very poor, so an additional arc extinguishing installation is added. In general, it is a DC hard-extinguishing arc, and the exchange has zero crossings, and arc extinguishing is easy.

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