When selecting a dual-power automatic transfer switch, many people tend to focus on one metric first: switching time. Indeed, switching speed is important, but experienced installers and purchasers know that the factors that truly affect the long-term performance of the equipment are not just this one.
In practical applications, an ATS does not simply switch between two power sources. Many users, when selecting the model, are actually more concerned about several more practical issues: Is the switching process reliable? Can the equipment operate stably for a long time? How well does it coordinate with the generator or PV system after installation?
Therefore, when choosing an ATS, merely focusing on one parameter is often insufficient. Factors such as reliability, compatibility, and structural design are equally important.
Basic Electrical Parameters
When selecting a transfer switch, the first thing that needs to be confirmed is the equipment’s electrical parameters. This is the first and most crucial step in the selection process. If these parameters do not match the system, even if other functions are excellent, it cannot be used properly.
The most common aspects that need confirmation include the following:
- Tension nominale: Must be consistent with the rated voltage of the power supply system (e.g., 110V/220V/230V/400V, etc.).
- Courant nominal: It is generally recommended that the rated current should not be less than 1.25 times the calculated load current. To give a simple example, assume the calculated load current for a certain circuit is 80A.
According to this principle:
ATS Rated Current ≥ 80A * 1.25
Calculation:
80 * 1.25 = 100A
Therefore, the rated current of the ATS selected for this circuit should be at least 100A.
The main purpose of this rule is to reserve a certain margin for load growth, and accommodate the instantaneous current surges that the transfer switch might encounter during switching, thereby ensuring the equipment can operate stably over the long term.
- Number of Poles: Common options are 2P, 3P, and 4P. 2P is suitable for single-phase power supply, while 3P/4P are suitable for three-phase four-wire power supply.
- Power Source Type: Some ATS units are primarily used for switching between the mains and a generator, while others are suitable for switching between a PVinverter and the mains. The characteristics of different power sources vary, so this needs to be confirmed before purchase.
In the actual procurement process, many problems often arise not from complex functions, but from mismatches in the most basic parameters. Therefore, before looking at products, confirming the basic electrical parameters of the system can help narrow down the selection range and avoid unnecessary trouble during subsequent installation.
Durability and Reliability
A good emergency power transfer switch usually does not require frequent replacement and can operate stably for many years. Therefore, when choosing a switch, durability is a factor that is worth giving special attention to.
Durability is mainly influenced by the following aspects:
Firstly, the quality of the casing material. High-quality insulating materials can provide better heat resistance and electrical safety performance, and can also maintain structural stability during long-term operation.
Secondly, the internal mechanical structure. The switching mechanism inside the ATS will continuously operate during the working process. If the structure design is not firm enough, wear or unstable operation will occur in the short term.
In some areas with unstable power grids, the equipment will undergo multiple switching operations every month. Over a long period of time, the number of operations is considerable.
Therefore, choosing a reliable and well-designed emergency power transfer switch can effectively reduce the risk of equipment failure, and reduce maintenance costs.
Compatibilité
The sources of backup power are becoming increasingly diverse, such as generators, batteries, and solar inverters.
Different power sources have different operating characteristics, so whether the commutateur de transfert d'alimentation de secours can coordinate well with these devices, is also an important factor to consider during selection.
Taking a generator as an example: when the mains power fails, the generator typically needs a certain amount of time to start and stabilize its power output. During this process, the ATS needs to coordinate with the generator’s control system, to prevent switching the load before the generator has successfully started, which would lead to a power outage for the load.
Protection Performance and Safety Design
When electrical equipment is in actual operation, it often operates under various different environmental conditions, such as being damp, having a lot of dust, or experiencing significant temperature variations.
Therefore, the equipment’s protection capability is also a factor that needs to be considered during the selection process.
A good sealing design for the casing can prevent dust and moisture from entering the equipment interior, thereby protecting the internal components. High-quality insulating materials can also reduce the risks of leakage or insulation aging.
Conclusion
Choosing the right solar uninterruptible power supply switch is not just about looking at the switching time parameter. Truly reliable equipment needs to achieve balance in multiple aspects, including stable switching performance, reliable mechanical structure, and good power compatibility.
For those engaged in electrical equipment sales, system installation, and new energy system construction, fully understanding these key factors can help them select solar uninterruptible power supply products, that are more suitable for actual application scenarios.
Only an ATS that performs reliably in all these aspects can provide stable, and safe power switching guarantees during long-term operation.
