Year1
- 21：
- 1
- 1：
- 12
- 132：
- 321
Transparent plastic case circuit breaker (hereinafter referred to as circuit breaker) is suitable for AC
, rated voltage of
or
, rated current to
circuits, as power distribution , used for overload and short-circuit protection of motors, and also for infrequent switching of circuits and infrequent starting of motors.
This product complies with standards.
2. Classification
Pole count order of circuit breaker Pole, two-pole, three-pole
The purpose of the circuit breaker is to distribute electricity and protect the motor (only applicable to three-pole
).
3. Operating environmental conditions
Installation location The altitude does not exceed
The ambient air temperature
■The upper limit of the ambient air temperature does not exceed +℃
■The average value of the ambient air temperature does not exceed +℃
■The lower limit of the ambient air temperature is not low At ℃
Atmospheric conditions
The relative humidity of the atmosphere does not exceed the maximum ambient temperature + ℃. It can have higher relative humidity at lower temperatures. For example, at + ℃, the maximum relative humidity is, And take into account the condensation that occurs on the surface of the crystal due to temperature changes
Installation conditions
Install in a place without shock, vibration and rain or snow, and the inclination with the vertical plane does not exceed.
Installation Category III
Dye level.
The main contact is usually a normally open contact, while the auxiliary contact often has two pairs of normally open contacts and normally closed contacts. Small contactors are often used as intermediate relays to cooperate with the main circuit. Use.
The contacts of the AC contactor are made of silver-tungsten alloy, which has good electrical conductivity and high temperature ablation resistance.
The power of the AC contactor action comes from the AC generated by the coil with iron core The magnetic field of the electromagnet is made up of two "mountain" shaped young silicon steel sheets. One of the fixed iron cores is covered with coils. The working voltage can be selected in a variety of ways. In order to stabilize the magnetic force, the attraction surface of the iron core is added Short-circuit ring. After the AC contactor loses power, it relies on a spring to return.
The other half is the movable iron core, which has the same structure as the fixed iron core and is used to drive the main contact and auxiliary contact to close and open.
Contactors with an ampere rating or above are equipped with an arc extinguishing cover, which uses the electromagnetic force generated when the circuit is disconnected to quickly break the arc and protect the contacts.
The contact device can be operated at high frequency and is used for power on and off control. The maximum operating frequency can reach times per hour.
The service life of the contactor is very high, the mechanical life is usually millions to ten million times, and the electrical life is generally hundreds of thousands to millions of times.
Technology Development
As a whole, the appearance and performance of AC contactors are constantly improving, but their functions remain the same.
Contactors (picture)
Regardless of the development of technology To some extent, ordinary AC contactors still play an important role.
Air electromagnetic contactors (English) are mainly composed of contact systems, electromagnetic operating systems, brackets, auxiliary contacts and shells (or chassis).
Because the coil of an AC electromagnetic contactor is generally powered by AC power, after the contactor is energized, there is usually a high-decibel noise, which is also a characteristic of electromagnetic contactors.
After the 1990s, various countries studied the silence and power saving of AC contactor electromagnets. One of the basic feasible solutions was to use a transformer to step down the AC power supply and then convert it into a DC power supply through an internal rectifier. However, this is complicated. Controls are rare.
Vacuum contactor Vacuum contactor is a contactor whose contact system uses a vacuum degaussing chamber.
Semiconductor contactor Semiconductor contactor is a contactor that completes current operation by changing the on-state and off-circuit state of the circuit loop.
Permanent magnet contactor The permanent magnet AC contactor is a micro-power contactor formed by using the principle of same-sex magnetic poles repelling each other and opposite-sex magnetic poles attracting each other, and replacing the traditional electromagnet drive mechanism with a permanent magnet drive mechanism.
Main classification
According to the form of the main contact connection circuit, it is divided into DC contactor and AC contactor.
According to the operating mechanism, it is divided into electromagnetic contactor and permanent magnet contactor.
The permanent magnet AC contactor is formed by using the principle of the same-sex magnetic poles repelling each other and opposite-sex attracting
Contactor (picture)
A micro-power contactor. Domestic mature product models,,,,,,,,,.
The permanent magnet with fixed polarity installed on the contactor linkage interacts with the variable polarity soft magnet solidified on the contactor base to achieve the purpose of attraction, retention and release. The variable polarity of the soft magnet is generated by the electronic module solidified with it to generate forward and reverse pulse currents of more than ten to twenty milliseconds, causing it to produce different polarities. According to the needs of the site, the control electronic module is divided into hydraulic contactor, pneumatic contactor and electromagnetic contactor according to the driving mode.
According to the action mode, it is divided into direct acting contactor and rotary contactor.
Main differences
The difference between contactors and relays The principle of contactors is the same as that of voltage relays, except that the load power controlled by the contactor is larger, so the volume is also larger. AC contactors are widely used in power interruption and control circuits. Relay is a small signal control electrical appliance, which is used for motor protection or automatic control of various production machinery.
The difference between a contactor and a circuit breaker. A contactor uses a coil to control the on and off of the circuit. After the contactor is energized,
Siemens Relay
The normally open one closes, and the normally closed one opens , controlled in this way.
It is true that circuit breakers are mainly used for protection. Its protection is currently more commonly used as three-stage protection, which is overload protection, short-circuit short-delay, and short-circuit long-delay. There are also some under-voltage, over-voltage and other protection functions. It depends on the brand and model. Its opening and closing can be manual or electric. There are three installation methods: fixed type and drawer type. According to the size of the current and the level of the working voltage, it can be divided into low voltage
Contactors are mainly used for industrial control. Generally, the loads are mostly motors. Of course, there are some heaters and dual power switching. The contactor is switched on and off by controlling the coil voltage. According to the different structures of arc extinguishing, it can be divided into vacuum contactor and ordinary contactor. According to different control voltages, they can be divided into DC contactors and AC contactors. Its main accessory is the auxiliary contact. The contact resistance between the contacts increases,
Contactor (Picture)
causing the temperature of the contact surface to be too high, causing the surface contact to become point contact, and even non-conduction. The causes of this failure include oil stains, lint, foreign matter on the contacts, long-term use, oxidation of the contact surface, defects caused by arc ablation, burrs or formation of metal shaving particles, etc., and jamming in the moving parts.
The treatment method is: for oil stains, lint or foreign matter on the contacts, you can wipe them with cotton cloth dipped in alcohol or gasoline. . If it is a silver or silver-based alloy contact,
Contactor (picture)
When the contact surface forms an oxide layer or is slightly burned or blackened under the action of arc, it generally does not affect the work. Alcohol can be used Scrub with gasoline or carbon tetrachloride solution. Even if the surface of the contact is burnt and uneven, you can only use a fine file to remove the surrounding splash beads or burrs. Do not file too much to avoid affecting the life of the contact.
For copper contacts, if the degree of burn is minor, you only need to use a fine file to repair the uneven areas. However, it is not allowed to polish with fine emery cloth to avoid quartz sand particles remaining between the contacts and unable to maintain the Good contact. If the burn is severe and the contact surface is low, the contact must be replaced with a new one.
If the moving part is stuck, it can be disassembled for inspection.
Maintenance and inspection Frequent or periodic inspection of the operation of the contactor,
Contactor (picture)
Performing necessary maintenance is an important measure to ensure reliable operation and extend its life. When inspecting and repairing, disconnect the power supply first and follow the steps below.
, Appearance inspection to remove dust, use cotton cloth dipped in a small amount of gasoline to wipe off the oil stains, then wipe dry with a cloth and wring it
WhatsApp
