First, the three major attributes of the AC contactor:
1. AC contactor coil. Ccoils are usually identified by A1 and A2, and can be simply divided into AC contactors and DC contactors. We often use AC contactors, of which 220 / 380V is the most commonly used:
2. AC Contactor Main contact. L1-L2-L3 is connected to the three-phase power supply inlet line, and T1 T2-T3 is connected to the power supply outlet line, and can be used to connect to the load line. The main contacts of the AC contactor are often open contacts, mainly connected to the main circuit, to control the start and stop of the motor and other equipment!
3. Auxiliary contacts of the AC contactor. The auxiliary contacts can be divided into constant open point NO and normally closed point NC.
3-1 Often open point NO, usually often open point NO is mainly used for contactor self-locking control and transfer operation signal to use, such as: AC contactor often open point NO to a red indicator light can be used as the motor operation indicator light, when the AC contactor power, often open point NO closed, turn on the indicator light, to transmit the motor or circuit operation signal.
3-2. Normal-closed point NC of the AC contactor. In general, NC is mainly used for circuit interlocking and signal transmission.
For example, the motor positive and reverse control circuit uses the interlocking function of the contactor constant closed point NC.
For example, the AC contactor constant closing point NC is connected to a green indicator light, which can be used as a stop indicator of the circuit or the motor. When the AC contactor is powered up, the constant closing point NC is disconnected, the stop indicator light is off, the corresponding operation indicator light is on, and the circuit runs.
Second, I understand the three external attributes of AC contactor, and then take a simple look at the inside of AC contactor:
First, the main components of the AC contactor: coil, iron core, reset spring, contact system and armature and other components constitute.
1. Simply understand the armature of the AC contactor. The armature connects the contact system, when the armature moves up and down, the contact point will change accordingly, such as: often open point NO closed, often closed point NC disconnected and so on, this is the basic usage!
2. Other important components: core, coils and reset springs! A brief understanding of this information is:
Here’s how AC contactors work in the most accessible language:
Before the AC contactor is not powered: the coil can not be electric, the core has no electromagnetic suction, the armature will not move, the spring elasticity remains normal, this time the often open point NO is off, the often closed point NC is on, this is the normal state.
AC contactor electric: coil electricity, iron core produce electromagnetic suction, can overcome the reset spring elasticity, pull the bit moved down, this time contact system will change: often open point NO closed, often closed point NC disconnected, this is the most basic contactor control, contactor is by contact on-off change to indirectly control the circuit!
After the AC contactor loses power or power off, the coil can not be electricity, the core has no electromagnetic suction, this time the reset spring elasticity drives the armature reset, armature bounce, this time the armature drives the AC contactor contact system movement, restore to the initial state: often open point NO disconnected, often closed point NC closed on.
Post time: Aug-17-2022
