In high reliability power supply scenarios such as industrial electricity, data centers, hospitals, etc., three-phase automatic transfer switches (ATS) are key equipment to ensure power continuity. How to choose the appropriate product for the conversion switch products on major e-commerce platforms? This article combines industry standards and practical experience to provide you with purchasing tips, helping you avoid selection errors and improve electrical safety!
What is a three-phase automatic transfer switch?
Three phase automatic transfer switch is used mainly to achieve automatic switching between two power supplies, such that when the main power supply is cut off, the standby power supply is switched in immediately, thereby avoiding losses caused by power interruption. ATS usually has the function of power supply voltage and frequency monitoring and can automatically detect the status of power supply.
Working principle
Automatic switching in case of main power failure: When the system detects a power outage or abnormal voltage of the main power supply, ATS will automatically activate the backup power supply to ensure the continued operation of the equipment.
Automatically switch back to normal power supply when restored: Once the main power supply stabilizes, ATS will automatically switch back to the main power supply to ensure the normal operation of the power system.
Tips for selecting three-phase automatic transfer switch
1. Determine the load capacity requirements
In order to select a three-phase automatic transfer switch, the first thing is to make sure its usable load capacity. The load capacity directly indicates the power that can be handled by the switch, so you must choose the appropriate rated current and rated power range according to actual application. A too small load capacity will make it overloaded, and a too large capacity will lead to unnecessary waste.
Calculate the rated current based on the total load power: for example, 63A is suitable for small and medium-sized factory equipment, while 100A or above is suitable for high-power scenarios such as hospitals and data centers.
The formula reference is: current (A)=total power (kW) x 1000/(1.732 x voltage (V) x power factor)
2.Structure type selection: PC grade vs CB grade
| Type | PC Grade | CB Grade |
|---|---|---|
| Features | Only carries current, no short-circuit interruption capability | Integrated circuit breaker, with overload protection functionality |
| Advantages | Fast switching speed (<50ms), long lifespan | Integrated protection, low maintenance cost |
| Scenarios | Data centers, precision instruments, and other high-reliability requirements | General commercial buildings, factories, and regular load conditions |
3.Selection of Switching Speed
STS static transfer switch (≤ 8ms)
Using controllable silicon (SCR) electronic components to achieve contactless switching, the action time can be controlled within 1/4 cycle (5ms).
Applicable scenarios:
IT equipment (servers, data centers): to avoid data loss or hardware damage caused by power outages;
Industrial precision instruments: ensuring the continuity of production processes and reducing downtime losses caused by voltage dips
Mechanical ATS (100ms-3s)
Mechanical contact switching is completed through electromagnetic or motor drive, and the action time is limited by the structure, with a typical range of 100ms-4.5s
Applicable scenarios:
Lighting system: Short term power outage does not affect use;
Ordinary commercial facilities (air conditioning, elevators): scenarios with low switching speed requirements
4.Selection of three-level and four pole ATS
Three pole ATS: only applicable to TN-C systems
Applicable scenario: In TN-C system (three-phase four wire system, PEN line integrated), when two power sources share the same neutral grounding point (such as the neutral point of the transformer shared by the mains and the oil engine), a three pole ATS can be used.
Four pole ATS (recommended): Mandatory use in multiple scenarios
Different grounding methods for dual power sources: It is necessary to completely isolate the neutral wires of the two power sources to avoid abnormal UPS zero ground voltage caused by zero line potential difference
Distribution system with leakage protection (RCD): Four pole ATS can prevent leakage current from forming a loop between the neutral lines of the dual power sources, preventing RCD from tripping incorrectly
IT system neutral line: The neutral point of the IT system itself is not grounded. If a neutral line is required for power supply, it must be isolated from the neutral line of the IT system through a four pole ATS
5.Environmental adaptability
According to different application environments, three-phase automatic transfer switches need to have good environmental adaptability. For example, when used in high-temperature and humid environments, ATS needs to have moisture-proof and dust-proof functions. Furthermore, for outdoor environments, it is particularly important to choose waterproof and UV resistant products.
6、 Intelligent function: Improve operation and maintenance efficiency
Remote monitoring: Supports Modbus communication, connects to SCADA system for real-time monitoring
Self check mode: Regular automatic switching test to avoid contact oxidation failure
Fault record: Store over 1000 event logs for easy fault tracing
7、 Brand and certification of three-phase transfer switch
When choosing a three-phase automatic transfer switch, brand and quality are key factors. High quality ATS can not only extend its service life, but also effectively reduce the failure rate.
Therefore, choosing reputable brand products will greatly enhance the reliability of the equipment. Next, I will recommend several high-quality three-phase automatic transfer switches on the market and their related information.
ONESTOP
ONESTO, as a global leading electrical brand, has never stopped emphasizing research and manufacturing of high-quality electrical products. Its three-phase transfer switches have outstanding reliability and durability, and can withstand complex and demanding working conditions.
Chint
Being a front runner in the electrical market in China, Chint’s three-phase conversion switches provide a price that is competitive with high performance, hence are appropriate for small and medium enterprises to attain balance between cost and quality.
Delixi
Excellent performance and long-term stability: Delixi three-phase conversion switch uses advanced manufacturing technology and superior materials, with high anti-interference ability and long-term stability, especially suitable for industrial equipment with high power, for stable and reliable electrical control.
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