DC Miniature circuit breakers Manufacturer


DC Miniature circuit breakers Manufacturer

As a leading manufacturer of DC Miniature Circuit Breakers, we provide reliable protection solutions for low voltage systems. Our high-quality DC Miniature Circuit Breakers are designed to efficiently detect and interrupt abnormal currents, safeguarding your electrical circuits and equipment.

Miniature Circuit Breaker (MCB) The first consideration when selecting electrical equipment or gadgets is safety. When the power fluctuates or an excessive amount of current flows, it produces damage in the form of an overload or short circuit. Therefore, it is vital to include a device as a safety factor to safeguard electrical devices/circuits against overcurrent. In the early days, the fuse was one of the most popular devices used to safeguard the circuit. A fuse has a metal wire or strip that melts when an excessive current flow occurs, therefore interrupting or halting the passage of electricity.

DC Miniature circuit breakers Manufacturer

What Is A Miniature Circuit Breaker

Miniature circuit breakers (MCBs) safeguard electrical systems from overloads and short circuits in homes, offices, and other buildings, as well as in industrial applications. After detecting a malfunction, the micro circuit breaker instantly disconnects the electrical circuit to prevent wire damage and the danger of fire. MCBs are equipped with two tripping mechanisms to ensure the safety of persons and property: a delayed thermal tripping mechanism for overload protection and a magnetic tripping mechanism for short circuit protection.

With both the thermal and magnetic tripping mechanisms installed, the ONCCY DC Miniature Circuit Breaker is intended to safeguard DC electrical installations from overloads and short circuits. The circuit breaker automatically shuts off the electrical circuit when a problem is found to protect the wires and reduce the possibility of a fire. When performing electrical maintenance, the circuit breaker can also be manually opened while carrying its full rated load without suffering any harm. The circuit breaker was designed for reversible connection; it may be wired in either direction and operates on bidirectional current. The built-in indicator window makes it easier to quickly determine the circuit breaker’s contact position. The buckle’s design makes it simple to install on a DIN rail that is the norm.

Main features

  • Compliant to worldwide product standards (CE, UL, TUU)
  • Characteristics: B, C, D, K, Z
  • Configurations: 1P, 1P+N, 2P, 3P, 3P+N, 4P
  • Breaking capacities up to 25 kA
  • Rated currents up to 100 A
DC Miniature circuit breakers Manufacturer
DC Miniature circuit breakers Manufacturer

Types of Miniature Circuit Breaker

The EDB1-63 DC Miniature Circuit Breaker is 1p,2p,3p,4p, double-throw device used to disconnect the power from a circuit. It is commonly used in low voltage applications to protect against overloads and short circuits. The EDB1-63 Miniature Circuit Breaker has a fixed current rating of 63 amps and a voltage rating of 250/1000 volts DC. The EDB1-63 Miniature Circuit Breaker also features a trip setting range of 10 to 63 amps.

EDB1-125 DC Mini Circuit Breaker

EDB1-63 Series MCB

Working Principle of MCB

Thermal-magnetic and thermal-magnetic release are the two primary types of tiny circuit breakers (TMR). Bimetallic strips that heat up as current flows through them are used in thermal magnetic breakers. The strip expands as a result of the heating, triggering a mechanism that opens the circuit.

The TMR tiny breakers, on the other hand, function similarly but employ an electromagnetic coil in place of bimetal strips for tripping. They are designed to trip at currents that are greater than what thermal breakers can handle. They frequently refer to themselves as air-cooled circuit protectors since they frequently use air as their heat source (ACP).

An ACB trips when there is too much current flowing through it or when the temperature exceeds permissible thresholds. Consequently, certain kinds of breakers are employed.

Uses of MCB

Make sure there is space in the electrical panel for the new breaker before installing a small circuit breaker. Each breaker must have a minimum of six inches between them, and no other breakers should be connected next to it.

By doing the following, you can install your new little circuit breaker:

1.Before performing any electrical system maintenance, make sure all of your equipment is turned off. Any lights, appliances, or other electrical devices in your home or place of business fall under this category.

2Locate a vacant slot in your electrical panel box and insert your new micro circuit breaker there. If extra panels are needed to accommodate more breakers but there aren’t any free places, think about replacing some older breakers with newer, more energy-efficient ones.

3 Remove the large screw holding down the current breaker and remove it from its slot. Then take out the old circuit breaker wires one at a time by pulling them out through their small holes in the side of the panel box. Take note of which wire goes where on each terminal before removing them from their sockets so that when you install new wires onto new miniature circuit breakers, you’ll know which wire goes where on each terminal.

4.Strip off about 3/8″ of insulation from each end of each wire before attaching it to its new corresponding terminal. Make sure you don’t strip off too much insulation because you’ll need enough left on each wire to secure it tightly onto its designated terminal.

5.Attach each wire to its selected terminal by pushing each wire firmly into place until it clicks into place. Then tighten each screw securely with your screwdriver so there is no chance for movement under normal conditions or during an electrical surge or power outage.

FAQ you want to know

What is Miniature Circuit Breaker (MCB)?

A switching device that can connect and disconnect loads under normal circuit conditions, and connect, carry and interrupt current for a certain period of time under abnormal circuit conditions (overload, short circuit, especially short circuit).

What parts does a low voltage circuit breaker consist of?

Low-voltage circuit breakers consist of several components including the contact system, arc extinguishing device, operating mechanism, and protective device.

  1. Contact System

The contacts (fixed and moving) in a circuit breaker are used to make or break the circuit. The basic requirements for contacts are:

a) They must safely and reliably make and break the circuit current, including the ultimate short-circuit current. b) They must handle the working current over a long-term operation. c) They should not wear excessively after making and breaking within the specified electrical life cycle.

Common types of contacts used in circuit breakers include butt contacts, bridge contacts, and plug-in contacts. Butt and bridge contacts are often surface or line contacts with silver alloy tips welded on. Large circuit breakers, in addition to the main contacts, also have auxiliary and arc contacts.

The sequence of operation for circuit breaker contacts is that upon closing, the arc contacts close first, followed by the auxiliary contacts, and finally the main contacts. When opening, the sequence is reversed. The main contacts carry the load current, auxiliary contacts protect the main ones, and arc contacts carry the arc during current interruption, ensuring the main contacts are not eroded by the arc, allowing for long-term stable operation.

  1. Arc Extinguishing System

The arc extinguishing system of a low-voltage circuit breaker is designed to extinguish the arc between contacts when the circuit is broken. It includes two parts: a powerful spring mechanism that quickly separates the contacts and an arc chute typically located above the contacts.

  1. Operating Mechanism

The operating mechanism of a circuit breaker consists of a driving mechanism and a trip mechanism.

a) The driving mechanism varies according to the operation mode of the circuit breaker and can be manual, lever-operated, electromagnet-driven, or motor-driven, with closing mechanisms being either energy-storing or non-energy-storing.

b) The free trip mechanism ensures the connection between the driving mechanism and the contact system.

  1. Protective Device

The protection of a circuit breaker is achieved through various trip units, including under-voltage, overcurrent, and shunt trip devices. Overcurrent trip devices can further be divided into overload and short-circuit trip devices.

a) Under-voltage trip devices monitor fluctuations in the working voltage. If the network voltage drops to 70%–35% of the rated voltage or a fault occurs, the circuit breaker can immediately trip, preventing closure at voltages below 35% of the rated voltage. Delayed action under-voltage trip devices prevent inappropriate tripping due to sudden load increases causing voltage fluctuations, with delays of 1s, 3s, and 5s.

b) Shunt trip devices are used for remote control disconnection or for tripping due to thermal relay actions.

c) Overcurrent trip devices protect against overloads and short circuits on the load side.

Generally, circuit breakers also feature short-circuit locking to prevent reclosing before a fault is cleared. Upon a short-circuit, the breaker trips, the locking mechanism activates, holding the breaker in the open position until the locking mechanism is reset, preventing circuit closure.

  1. Others

In addition to the above devices, circuit breakers also have auxiliary contacts, typically normally open and normally closed, used for signaling and intelligent control devices.

How to classify low voltage circuit breakers?

Low-voltage circuit breakers are categorized as follows:

  1. By application type, they are divided into selective (with adjustable protection device parameters) and non-selective (with non-adjustable protection device parameters).
  2. By structural type, they are classified into universal (also known as frame type) and molded case type.
  3. By arc extinguishing medium, they are categorized into air type and vacuum type (with air type being more common domestically).
  4. By operating mechanism, they are differentiated into manually operated, electrically operated, and spring-charged mechanical operation.
  5. By pole number, they are divided into single pole, double pole, triple pole, and quadruple pole types.
  6. By action speed, they are classified into standard type and fast type. The fast type includes AC fast type and DC fast type. The AC fast type, commonly known as current-limiting circuit breaker, has a breaking time short enough to interrupt the short-circuit current before it reaches its expected peak value; the DC fast type also achieves a breaking time short enough to interrupt the short-circuit current before it reaches its maximum value.
  7. By mounting method, they are divided into fixed, plug-in, draw-out, and embedded types.
  8. By purpose, they are classified into distribution circuit breakers, motor protection circuit breakers, de-magnetizing circuit breakers, and residual current circuit breakers, among others.

Is it normal if the miniature circuit breaker generates heat during use?

In the use of miniature circuit breakers, experiencing some degree of heating is a subject of consideration. According to the national standard GB10963.1 (equivalent to IEC60898-1), under specified conditions, the limit temperature rise for various parts of the circuit breaker is as follows: the terminal for connecting external conductors should be less than or equal to 60K; surfaces that may be touched during manual operation should be less than or equal to 40K; and surfaces in direct contact with the mounting plane should be less than or equal to 60K.

How to connect MX+OF? What are its operating conditions?

The MX+OF auxiliary contact unit wiring and its operating conditions are as follows:

“C2” should be connected to the phase line of an AC power source (or the positive terminal of a DC power source), while “C1” is wired through an external control. The MX+OF has 4 terminals for wiring. When wiring, the working voltage should be connected to terminals C1 and C2. “C2-14” should make contact when the circuit breaker is in the “open” and “closed” positions, respectively, eliminating the need to use these two contact points to connect to the AC power source’s neutral line (or the negative terminal of a DC power source). The active contact “C2-12” allows for terminals 12 and 14 to be left unconnected. It is strictly prohibited to connect working voltage to terminals “C1, 14”. Connecting power to “C1, 14” will burn out the MX coil.

The operation of MX requires a specific amount of energy. If this energy requirement is not met, the operation of MX cannot be guaranteed. The pull-in power of the MX+OF shunt release unit is related to its operating voltage and varies significantly. When selecting a model, one should refer to the pull-in power table provided in the catalog.

The transfer contact is an active contact and must not be used as a dry contact or connected to other low-voltage modules.

What is the fine-tuning step size of the circuit breaker controller?

The long-delay protection can realize adjustment in steps of 1A, and the trip delay time step is 0.5 seconds. Short-delay protection can realize adjustment with a step size of 1A. Instantaneous protection can realize adjustment with a step size of 10A.

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