Motor and electrical control technology knowledge
The motor is what we usually call the "motor". The motor is an electromagnetic device that converts or transmits electric energy according to the law of electromagnetic induction. The main function of the motor is to generate drive torque as a power source for electrical appliances or various machines. Some of the basic knowledge of motor and electrical control technology is something to keep in mind, both in learning and at work.
1, low-voltage electrical appliances
It refers to an electrical appliance that functions as an on/off, protection, control or regulation in a circuit with an AC rated voltage of 1200V and a DC rated voltage of 1500V or less.
2, the main electric appliance
An appliance used in an automatic control system to send control commands.
3, fuse
It is a simple short circuit or severe overload protection appliance whose main body is a melt made of low melting point wire or foil.
4, time relay
A control device in which a contact is delayed or turned off.
5, electrical schematic
The electrical schematic diagram is a circuit diagram used to indicate the connection relationship and working principle of the conductive components in the electrical components of the circuit.
6, interlocking
An "interlock" circuit is essentially a combination of two inhibit circuits. The K1 action disables the power of K2, and the K2 action disables the power of K1.
7, self-locking
The circuit self-locking circuit is an action of interlocking the output signal itself to maintain the output.
8, zero pressure protection
In order to prevent the self-starting of the motor when power is restored after the grid is de-energized, it is called zero-voltage protection.
9, undervoltage protection
When the power supply voltage drops below the allowable value, in order to prevent the control circuit and the motor from working abnormally, it is necessary to take measures to cut off the power supply, which is undervoltage protection.
10, star connection
Three windings, one end connected to one phase of the three-phase voltage and the other end connected together.
11, delta connection
The three windings are connected end to end, and three voltages are respectively connected at the three connection ends.
12, decompression start
When the motor capacity is large, the power supply voltage is lowered into the stator winding of the motor to start the motor.
13, the main circuit
The main circuit is a circuit from the power source to the end of the motor or line, and is a circuit through which a strong current flows.
14, auxiliary circuit
The auxiliary circuit is a small current through the circuit.
15, speed relay
A non-electrical signal detecting device with a rotational speed as an input, which can output a switching signal when the measured rotational speed rises or falls to a predetermined set value.
16, relay
A relay is a control element that uses a variety of physical quantities to convert a power or non-electricity signal into an electromagnetic force (with contact) or a step change in the output state (no contact).
17, thermal relay
It is a protective device that works by the principle of the thermal effect of current.
18, AC relay
A relay that draws the coil current to AC.
19, full pressure start
When the motor capacity is small, the stator winding of the motor is directly connected to the power source and started at the rated voltage.
20, voltage
The potential difference across the circuit.
21, the contact
The contact, also called the contact, is the actuator of the electromagnetic appliance and functions as a switch-on and break-off circuit.
22. Electromagnetic structure
The electromagnetic mechanism is a sensing component of an electromagnetic appliance that converts electromagnetic energy into mechanical energy, thereby driving the contact action.
23, the arc
The arc is actually a discharge phenomenon caused by a gas between the contacts under the action of a strong electric field.
24, contactor
The contactor is an automatic control switchgear suitable for long-distance control, frequent operation of AC and DC main circuits and large-capacity control circuits in low-voltage power distribution systems.
25, temperature relay
A protective device that operates by indirectly reflecting the temperature of the winding by the overheating element is called a temperature relay.
26, jog circuit
When the jog button is pressed, the coil is energized and pulled, the main contact is closed, the motor is connected to the three-phase AC power supply, and the rotation is started; when the button is released, the coil is discharged, the main contact is disconnected, and the motor is powered off and stopped.
27. Electrical control system
The electrical control system is made up of electrical control components connected according to certain requirements.
28, variable pole speed
In the speed regulation of asynchronous motor, the speed control method of changing the pole number of the stator pole is used.
29, electrical components location map
The electrical component layout is a diagram used to indicate the actual mounting location of the components in the electrical principle.
30, electrical components wiring diagram
The electrical installation wiring diagram is a specific implementation form of the electrical schematic diagram, which is drawn by the specified graphical symbols according to the actual position and actual wiring of the electrical components.
31, frequency control
In the speed regulation of asynchronous motor, the speed control method of changing the power frequency.
