Full explanation of knowledge about dual power automatic transfer switch

A dual power automatic transfer switch is a device that can reliably switch between two power sources. It is composed of one or several switching electrical appliances and other necessary electrical appliances, which are used to detect the power supply circuit and automatically convert one or more load circuits from one power source to another power source.

The dual power automatic transfer switch has three switching functions: automatic switching, automatic recovery, automatic switching and non-automatic recovery, and grid-generator. Carry out real-time detection, when any phase has overvoltage or undervoltage (including phase loss), it can automatically switch from abnormal power supply to normal power supply. To put it simply, one way is commonly used and one way is reserved. When the common power suddenly fails or the power is cut off, it is automatically put into the backup power supply through the dual power switch, (the backup power supply can also be powered by the generator under small load), so that the equipment can still operate normally. . The dual power automatic transfer switch can also be used in the grid-generating system products and can issue power generation and unloading commands. It is a dual power system product with perfect performance, safety and reliability, high degree of automation and wide range of use. At present, the most common ones are elevators, fire protection, monitoring, and UPS uninterruptible power supplies used by banks, but their backup is a battery pack. Most of the factories, mines or units with first-class and second-class loads have them.

working principle
After entering the working state, the controller will automatically sample the data of each voltage of the two power supplies continuously, and calculate the RMS voltage of each item. The time (adjustable) drive circuit sends the opening or closing command to the operating mechanism, and realizes the normal, standby and double switching of the switch by controlling the forward and reverse rotation of the motor, and the fault status can be reflected by the LED digital tube and indicator light.
structure

The dual power automatic transfer switch is composed of two three-pole or four-pole BM1 series molded case circuit breakers and accessories (auxiliary, alarm contacts), motor transmission mechanism, mechanical interlocking mechanism, intelligent controller, etc. Divided into integral and split. The integral type is that the control and the actuator are installed on the same base; the split type is that the controller is installed on the panel of the cabinet, the actuator is installed on the base and installed in the cabinet by the user, and the controller and the actuator are connected by a cable of about 2m long. . There is a reliable mechanical interlocking device and electrical interlocking protection between the two executive circuit breakers, which completely eliminates the possibility of closing the two circuit breakers at the same time.
The structure of the dual power automatic transfer switch:
1. Contactor type: It is formed by overlapping two AC contactors and some interlocking devices.
2. Circuit breaker type: It is composed of two circuit breakers and an external mechanical interlocking device.
3. Load switch type: It is composed of two load switches and a set of built-in interlocking mechanism.
4. Double-throw type: It is driven by electromagnetic force, the built-in unloading structure maintains the state, and the single-pole double-throw integrated transfer switch

Classification
Dual power supply power supply power switch switch switch switch is divided into two categories: ATS and STS1) STS (StaticTransferSwitch)
1) Static switch: also known as static transfer switch.
It is an automatic switching system for two power sources. When the first channel fails, the STS automatically switches to the second channel to supply power to the load. If the second channel fails, the STS automatically switches to the first channel to supply power to the load. It is suitable for uninterrupted power conversion of any two-way power supply, such as UPS-UPS, UPS-generator, UPS-mains, mains-mains, etc. STS static switch is mainly composed of intelligent control board, high-speed thyristor, and circuit breaker. Its standard switching time is ≤8ms, which will not cause IT load power failure. It not only provides reliable power supply to the load, but also ensures the safety of STS when switching between different phases.
2) ATS automatic transfer switch: ATS (Automatictransferswitchingequipment), automatic transfer switch.
ATS is mainly used in emergency power supply system to automatically switch the load circuit from one power source to another (backup) power source to ensure the continuous and reliable operation of important loads. ATS is a mechanical structure, and the conversion time is more than 100 milliseconds, which will cause the load to lose power. Suitable for lighting and motor loads. The automatic transfer switch adopts dual-row composite contacts, horizontal pull mechanism, micro-motor, micro-motor, micro-motor, micro-motor, and micro-motor pre-energy storage and micro-control technology, which basically realizes zero arcing. The drive motor is a polychloroprene rubber insulated damp-heat motor, equipped with a safety device that automatically trips when the temperature exceeds 110°C and the current state of overcurrent current. After the fault disappears, it will be automatically put into operation, which ensures the life of the switch to a large extent.

Features
■Using double-row composite contacts, horizontal connection mechanism, micro-motor pre-storage and micro-electronic control technology to basically achieve zero arcing (without arc extinguishing cover)
■Adopt zero-crossing technology
■Good safety performance.
■Using double-row composite contacts, horizontal-pulling mechanism, micro-motor pre-energy storage and micro-electronic control technology to basically achieve zero arcing (without arc extinguishing cover).
■Adopt reliable mechanical interlocking and electrical interlocking.
■With zero-crossing technology, it can be forced to zero in an emergency (cut off two power supplies at the same time).
■With obvious on-off position indication, padlock and other functions, the isolation between the power supply and the load can be reliably realized.
■Mechatronics design, switch conversion is accurate, flexible and smooth.
■Good electromagnetic compatibility, strong anti-interference ability, no external interference.
■High degree of automation.
■The switch has multiple input/output interfaces, which is convenient for remote PLC control and system automation.
■Open magnetic work does not require any external control components.
■Beautiful appearance, small size and light weight.
■It has obvious on-off position indication and padlock function, which can reliably realize the isolation between the power supply and the load
■High reliability, the service life is more than 8000 times
■Fully automatic type without any external control components

Features
★The position of the switch is ensured by the logic control board, with different logics to manage the motor directly installed in the switch and the operation of the gearbox.
★The motor is a polychloroprene rubber insulated damp heat type motor with safety device, which will trip when the humidity exceeds 110℃ and the overcurrent state. Automatically put into work after the fault disappears, the reversible reduction gear adopts spur gear
★There is a reliable mechanical interlocking device and electrical interlocking protection between the two circuit breakers, which completely eliminates the possibility of closing the two circuit breakers at the same time. The agency has obtained national patent products.
★Intelligent controller adopts single-chip microcomputer as the control core, with simple hardware, powerful functions, convenient expansion and high reliability.
★It has the function of short circuit and overload protection, automatic conversion function of overvoltage, undervoltage and phase loss and intelligent alarm function.
★Automatic conversion parameters can be freely set externally.
★It has the function of intelligent protection of operation motor.
★The device is equipped with a fire control circuit. When the fire control center sends a control signal to the intelligent controller, both circuit breakers will enter the open state.
★The computer networking interface is reserved for remote control, remote adjustment, remote signaling, and remote measurement.
★With generator start signal function, ATS controller will send a start signal when the common power supply is abnormal to start the generator automatically.

Scope of application
Dual power automatic transfer switch (A.T.S for short) is suitable for emergency power supply system with rated working voltage of 240/415V and frequency of 50/60Hz. When one power supply fails, the conversion between the common power supply and the standby power supply can be automatically completed without manual operation to ensure the reliability of the power supply for important users. It is mainly used in hospitals, shopping malls, banks, civil air defense, chemical, metallurgical , high-rise buildings, military facilities and fire protection and other important places that do not allow power outages. This product complies with IEC60947-6-1, GB/T14048.11 (automatic transfer switch electrical appliances) standards, and also meets (fire protection regulations for high-rise civil buildings), (building design fire protection regulations), (emergency lighting design guidelines), (civil building electrical design specification), etc.

Dual power automatic transfer switch working mode
1) Automatic.
When the user sets the automatic function, the switching of the automatic transfer switch is automatically controlled by the controller according to the fault condition. Power grid and generator: (F2) mode, when the automatic transfer switch is used in the power grid and generator system, the controller switches the two power sources of the power grid and the generator, and sends a passive electric shock signal when the power grid power fails. A set of normally open and normally closed contact outputs) is used to start the generator system. When the generator voltage reaches the rated requirement, the controller will convert it. As for the system capacity, it is configured by the user. When the generator capacity is limited , you can remove part of the load first to avoid dragging; when the grid returns to normal, the automatic transfer switch will automatically switch to the grid power supply.
2) Manually.
When in manual mode, the user can operate the buttons on the controller panel to switch the transfer switch as required. There are three positions to choose from: common power position, backup power position, and dual-point position.

Operating procedures
1. When there is a power outage for some reason, and the power supply cannot be restored in a short time, the backup power supply must be enabled. step:
① Cut off the circuit breakers of the mains power supply (including the circuit breakers in the control cabinet of the power distribution room and the city power supply breaker in the dual power switch box), open the double throw anti-reverse switch to the side of the self-provided power supply, and keep the dual power switch box inside The self-supplied power supply circuit breaker is off.
②Start the standby power supply (diesel generator set), and when the standby set is running normally, close the generator air switch and each circuit breaker in the control cabinet of the self-supplied power supply in sequence.
③Close each backup power circuit breaker in the power switch box one by one to transmit power to each load.
④ During the operation of the standby power supply, the operator on duty shall not leave the generator set, and adjust the voltage, plant frequency, etc. in time according to the change of the load, and deal with the abnormality in time.
2. When the mains power supply is restored, the power conversion work should be done in time, the backup power supply should be cut off, and the mains power supply should be restored.

step:
① Disconnect each circuit breaker of the self-supplied power supply one by one in sequence, the order is: the self-supplied power supply circuit breaker of the dual power switch box → each circuit breaker of the self-supplied power distribution cabinet → the main switch of the generator → the double-throwing switch to the mains power supply side.
② Stop the engine according to the steps of stopping the diesel engine.
③Close the circuit breakers one by one from the mains power supply main switch to each branch switch in sequence, and place the dual power switch box from the mains power supply circuit breaker to closed.