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Circuit Breaker Function And Function
Sep 26, 2017

The main products are DWl5, DWl6, DWl7 (ME), DW45 and other series, Molded Case Circuit Breaker mainly produces DZ20, CMl, DWl6, DWl7 (ME), DW45 series, , TM30 series. Circuit breakers are made up of body and accessories. The body is free of any accessories, but can ensure smooth, sub-circuit, and in the circuit or equipment overload, short circuit and other accidents, automatically cut off the fault function, and accessories as a circuit breaker function derived supplement for the circuit breaker to increase The control means and the expansion of the protection function, so that the use of a wider range of circuit breakers, more complete protection, operation and installation more. The current circuit breaker accessory has become an important part of the circuit breaker inseparable. But the annex is not the more complete the better, it is necessary according to the specific control lines and protection lines to rational use of accessories, to avoid unnecessary waste, and to distinguish the voltage level, AC or DC, auxiliary contact logarithm , Such as improper application, not only can not afford to protect, but also cause great economic losses. The following analysis of the function and application of the circuit breaker accessories allows the user to help with the application of the circuit breaker accessories.

First, the internal annex

1. Auxiliary contact; and the main circuit of the circuit breaker, the mechanical contact on the mechanism, mainly for the circuit breaker, the state of the display, connected to the circuit breaker in the control circuit through the circuit breaker division, its Related to the implementation of electrical control or interlock, for example, to the signal lights, relays and other output signals. Universal circuit breaker has six pairs of contacts (three normally open, three normally closed), DW45 has eight pairs of contacts (four normally open, four normally closed). Mold case circuit breaker rated rated current 100A for a single breakpoint switch, 225A and above for the bridge contact structure, the agreement heating current of 3A; shell rated rated current 400A and above can be installed two permanent open, two often Closed, the agreed heating current of 6A. The number of operating performance is the same as the total number of operating performance of the circuit breaker.

2. Alarm contact: for the circuit breaker accident alarm contact, and this contact only when the circuit breaker trip after breaking action, mainly for the circuit breaker load overload or under voltage and other failures when the free trip, alarm Contact from the original normally open position into a closed position, connected to the auxiliary line of the lights or bells, buzzers, etc., to show or remind the circuit breaker fault trip status. As the circuit breaker due to load failure and the probability of free tripping is not too much, so the life of the alarm contact is the breaker life of 1/10. The working current of the alarm contact is generally not more than 1A.

3. Shunt release: is a voltage source excitation of the release, and its voltage can be independent of the main circuit voltage. The shunt release is a remote accessory accessory accessory. When the power supply voltage is equal to the rated control power supply voltage between 70% -110% of any voltage, you can reliably break the circuit breaker. Shunt release is a short-term work system, the coil power is generally not more than 1S, otherwise the line will be burned. Molded Case Circuit Breaker In order to prevent the coil from burning, in the shunt trip coil in series with a micro-switch, when the shunt release through the armature pull, micro-switch from the normally closed state into normally open, due to shunt release power Of the control line is cut off, even if artificially hold down the button, the excitation coil is no longer energized to avoid the coil burning situation. When the circuit breaker and then close the closing, the micro switch is again in the normally closed position. But omnipotent DW45 products in the factory by the user in the use of shunt trip before the coil in front of a group of normally open contacts.

4. Undervoltage release: The undervoltage release is a release that delays the circuit breaker with or without delay when its terminal voltage drops to a specified range. When the supply voltage drops (even Slow down) to 70% to 35% of rated operating voltage, undervoltage release should be operated, undervoltage release When the supply voltage is equal to 35% of the rated operating voltage of the release, the undervoltage release Can prevent the circuit breaker is closed; power supply voltage is equal to or greater than 85% of the undervoltage release rated operating voltage, in hot conditions, should ensure that the circuit breaker reliable closed. Therefore, when the power supply voltage in the protection circuit to a certain voltage drop, can automatically disconnect the circuit breaker to cut off the power supply, so that the following circuit breaker electrical equipment or electrical equipment from undervoltage damage. When used, the undervoltage release coil is connected to the power supply side of the circuit breaker, and the circuit breaker can be closed after the undervoltage release is energized. Otherwise, the circuit breaker can not be closed.

Second, external accessories

1. Electric operating mechanism, is used for remote automatic opening and closing circuit breaker of an annex, electric operating mechanism with motor operating mechanism and electromagnet operating mechanism of two, the motor operating mechanism for the molded case circuit breaker frame rated current rating 400A and above circuit breakers and universal circuit breakers, electromagnet operating mechanism for molded case whisper shell frame rated current 225A and below circuit breakers, whether it is electromagnet or motor, their suction and rotation direction are the same , Only by the position of the cam inside the electric operation mechanism to reach the combination, the circuit breaker in the use of electric motor operation, the rated control voltage between 85% -110% of any voltage, should be able to ensure reliable circuit breaker closure.

2. Explosive electromagnets: This release solenoids are suitable for use with universal circuit breakers with motor pre-energy storage mechanisms (energy storage mechanism for its operating spring mechanism). When the user presses the button, the solenoid coil is energized, the electromagnet closes to release the storage spring, and the circuit breaker closes.

3. Turn the operating handle, apply to the molded case circuit breaker, the mechanism of turning the handle on the circuit breaker, the shaft of the handle is fitted in its mechanism fitting hole, the other end of the shaft through the door of the drawer cabinet, The handle is mounted on the door above the door of the set of devices, and the handle of the round or square seat is screwed to the door. This installation allows the operator to turn the door through the handle of the handle clockwise or counterclockwise Ensure that the circuit breaker is closed or opened. While turning the handle to ensure that the circuit breaker is closed, the door can not be opened; only the handle in the opening or re-buckle, switch board door to open. In an emergency, when the circuit breaker is in the "closing" and the door panel needs to be opened, press the red release button on the side of the handle.

4. Lengthened handle: is an external long handle, directly mounted on the handle of the circuit breaker, generally used for 600A and above the large-capacity circuit breaker, the manual closing operation.

5. Handle locking device: the handle box is installed on the card, the handle on the hole and then locked with a padlock. Mainly used in the circuit breaker in the closed working state, do not allow other people to open the door caused by power outages, or circuit breaker load side of the circuit needs to be repaired or not allowed to power, to prevent the wrong circuit breaker closing, to protect Maintenance personnel safety or reliable use of electrical equipment.

6. Wiring: circuit breaker wiring way before the board, the board, plug-in, drawer, the user if no special requirements, according to the board before the supply, board wiring is a common wiring.

(1) board wiring: board wiring is the biggest feature is the replacement or maintenance of circuit breakers, do not have to re-wiring, only the front power supply disconnected. Because of the special structure, the product has been designed according to the design requirements of the special installation board and mounting screws and wiring screws, need special attention is due to the reliability of large-capacity circuit breaker contact will directly affect the normal use of circuit breakers, Must be taken seriously and strictly in accordance with the requirements of the manufacturer to install.

(2) plug-in wiring: the installation of the installation of the device board, the first installation of a circuit breaker mount, the installation of six plugs, the circuit breaker connection board has six sockets. The mounting seat has a connecting plate or a mounting seat, and the mounting seat is pre-connected with the power cord and the load line. When used, insert the circuit breaker directly into the mounting seat. If the circuit breaker is broken, just pull out the bad, put a good can. It is the replacement time than the board, board wiring is short, and convenient. Due to plug, pull need a certain amount of manpower. So the current plug-in products in China, the shell current limit of up to 400A. Thus saving maintenance and replacement time. Plug-in circuit breakers should check whether the plug of the circuit breaker is tightened and the circuit breaker should be tightened safely to reduce the contact resistance and improve the reliability.

(3) drawer wiring: the circuit breaker into and out of the drawer is clockwise or counterclockwise rotation, in the main circuit and the secondary circuit are used in the plug-in structure, omit the fixed type of necessary isolator, do To a machine with two, to improve the use of the economy, while the operation and maintenance to bring a great convenience, increased security and reliability. In particular, the main drawer seat of the drawer seat can be used with the NT type fuse breaker, so that the fuse can be directly inserted into the emergency state.

Third, the conclusion

As the shunt release, undervoltage release, electric operating mechanism and latching electromagnet with different voltage levels and AC, DC different power supply, the user to specify when ordering, while the user can not use a single selection Annex, for two circuit breakers electrical interlock (when a closing, another must be sub-gate) can be used auxiliary contact and shunt release or electric operating mechanism, before the board and board wiring Always tighten the screws to avoid burning the circuit breaker.