Automatic Transfer Switch: Importance and Operating Principles
When working with electrical networks, various problems related to voltage spikes can arise. These spikes negatively affect the operation of electrical devices, especially when it comes to precise equipment that ensures people's safety. Therefore, enterprises in telecommunications, transport, residential construction, and many other fields use automatic transfer switches (ATS). Their main function is to automatically switch to a backup power source during sudden voltage spikes.
Key Concepts for Understanding ATS Operation
To better understand the principle of automatic transfer switches, it is important to become familiar with the following concepts:
- Rated Current: a parameter that determines the maximum current that circuit breakers can provide.
- Number of Inputs: the total number of independent power sources from which automatic transfer switching is performed.
- Type of Locking: the main difference between different panels. There are two key types of locking, which will be described further.
- Mechanical Locking: a method that prevents the connection of other switching elements using special devices, such as levers — special contacts related to the locking unit.
- Electrical Locking: implemented through electrical circuits, the algorithm of which is pre-designed.
Types of Power Sources in ATS
In automatic transfer switch panels, there is a variety of power sources — from traditional electrical networks to diesel generators.
Operating Modes of ATS
Switchgear has several operating modes: mechanical and electrical locking, also referred to as manual and automatic modes. The automatic mode, in turn, has several variations:
- Priority First Input ATS: in this mode, if the main power source fails, the backup source is automatically connected. The system does not need to know the cause of the failure.
- ATS with Equal Inputs: when power is supplied from multiple sources, a mode is activated where the first input operates first, and upon its failure, it automatically switches to the second. In such systems, manual switching is provided, but this does not make them a manual mode.
Manual Mode of ATS Operation
In manual mode, switching from one source to another is possible only via the "start/stop" button. Some manufacturers offer combined types of locking that allow the automatic mode to make switching decisions while simultaneously providing the option for manual control. This ensures an optimal workflow for various enterprises.