Electrical system composition
The basic circuit of the commonly used control circuit consists of the following parts.
(1) Power supply circuit. The power supply of the power supply circuit includes AC380V and 220V.
(2) Protection circuit. The working power of the protection (auxiliary) circuit is single-phase 220, 36V or DC 220, 24V, etc. It performs various protections such as short circuit, overload and voltage loss on electrical equipment and lines. It consists of fuses, thermal relays and voltage loss coils , Rectifier components and voltage stabilizer components.
(3) Signal circuit. Circuits that can timely reflect or display information about normal and abnormal working conditions of equipment and lines, such as different-colored signal lights, and different acoustic equipment.
(4) Automatic and manual circuits. In order to improve the working efficiency of electrical equipment, automatic links are generally provided, but in the installation, commissioning and emergency handling, manual links need to be set in the control circuit, and the automatic or manual conversion can be realized through combination switches or transfer switches.
(5) Brake parking circuit. Cut off the power supply of the circuit, and take some braking measures to control the motor quickly, such as energy consumption braking, reverse power braking, reverse pull reverse braking and regenerative power generation braking.
(6) Self-locking and blocking the same road. After the start button is released, the line remains energized, and the electrical link in which the electrical equipment can continue to work is called a self-locking link. For example, the moving contact of the contactor is connected in series in the coil circuit. Two or more electrical devices and components, in order to ensure the safe and reliable operation of the equipment, only one can be powered on to start, and the other protection link that cannot be powered on is called a lockout link. For example, the dynamic break contacts of two contactors are connected in series in the opposite coil circuit.