20+ Years Experience
Automatic Transfer Switch

Established in 1999, 123 electric is the industry leading manufacturer of dual power automatic transfer switching equipment (ATSE)! More than 20 years of industry experience can provide you with the solutions you can think of in design, manufacturing and distribution.

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Our ATSE market share in China has exceeded 60%.

Available in 16A~4000A designs, allowing you the flexibility to choose the switching function that best suits your application.

In addition to a full range of ATSE solutions, we also provide cost-effective OEM and ODM services.

Products have third party testing certifications such as CE, SGS, UKCA, ISO, CQC and CCC – all available on request.

We support a global customer base through global sites in the Americas, EMEA, APAC and ASEAN, and have a broad network of authorized channel partners in all regions.

All 123 products enjoy a standard 2-year warranty. Feedback the solution within 24 hours, and the engineer arrives at the scene within 48 hours. For additional levels of support, extended warranty options are available for peace of mind.

PC Class Automatic Transfer Switch

PC automatic transfer switch referred to as ATS,does not have overload and short circuit protection function, its executive element for the isolation switch, its driving element for the electromagnetic coil, the action speed is very fast.

CB Class Automatic Transfer Switch

CB automatic transfer switch referred to as ATS, overload and short circuit protection function, its executive element is the circuit breaker, its driving element is the motor, the action speed is relatively.

A Brief Self-Nomination, Why Choose 123?

Founded in 1999, 123 electric is an industry leader in Dual Power Switching Equipment (ATSE) with 20 years of experience in the design, manufacture and distribution of solutions.
Has 7 First-Time Creators

Launched China's first integral type YUQ3 special CB ATSE in 2015.

The first ATSE manufacturer that can provide AC-DC and DC-DC switchover.

The first ATSE manufacturer in China that can provide 16A-3200A current level of the same structure (special PC level).

The first ATSE manufacturer in China that can provide pull-out type with bypass.

The first ATSE manufacturer in China that can provide Instantaneous closed circuit switchover.

The first ATSE manufacturer in China that can provide neutral line overlap switchover.

The first ATSE manufacturer that can provide AC-DC and DC-DC switchover.

What is a dual power automatic transfer switch ?

Automatic transfer switch appliances consist of one or more transfer switch appliances and other necessary appliances, which are used to monitor power circuits and automatically transfer one or more load circuits from one power source to another.

In the event of a sudden failure or power failure of ordinary power, according to the dual power transfer switch, the backup power supply will be fully automatically put into use (the backup power supply can also be powered by the generator system under a small load), so that the mechanical equipment can still operate normally.

How to choose the correct automatic transfer switch?

Determinants for selecting an automatic transfer switch:
Selection of automatic transfer switches is important to ensure maximum reliability and adequate capacity for normal and emergency situations.There are many different factors to consider when selecting an automatic transfer switch, the most important being size, load type, rated voltage and rated continuous current.

PC Class
CB Class

The industry classifies automatic transfer switch loads as total system loads, motor loads, discharge lamp loads, restrictive loads, and incandescent loads.

Rated voltage

An automatic transfer switch is something a technician connects to two power sources that are out of sync. The voltage rises when an automatic transfer switch swaps two sources. The switch should experience such voltage fluctuations to provide seamless supply.

AC systems are usually rated at 120, 208, 240, 480, 600 volts, single or multiple phase. The standard frequency is 50 or 60 Hz. Automatic transfer switches are available for other voltages and frequencies if required, this also includes DC.

Rated Continuous Current

Automatic transfer switches are manufactured to meet continuous current ratings from 16-4000 amps.

The standard expectation for automatic transfer switches for continuous loads is that the switch should be able to hold a maximum of three hours or more. Transfer switches differ from other emergency equipment in that they must constantly deliver electrical current to critical loads, whether from normal or emergency sources. A standby engine generator set, on the other hand, typically provides power only in emergency situations.

What are the classification and difference
of dual power supply?

Dual power supply is mainly divided into PC automatic transfer switch and CB class automatic transfer switch.
PC-level dual power supply

Dual power supply capable of connecting, carrying, but not used to break short-circuit current.

If the dual power supply chooses the load switch without over current release as the actuator, it belongs to the PC-level automatic transfer switch. It does not have a protection function, but it has a high tolerance and connection ability, which can ensure the safety of the switch itself, and is not damaged by faults such as overload or short circuit. In this case, a reliable connection circuit is guaranteed.

Class CB dual power supply

Dual power supply equipped with over current release, its main contact can be connected and used to break short-circuit current.

The dual power supply should choose a circuit breaker with only a short-circuit current release as the actuator, which belongs to the CB-level automatic transfer switch. With selective protection function, it can provide short-circuit protection for the lower load and cable; its making and breaking capacity is much greater than that of other components such as contactors and relays.

Precautions for using dual power switch

Dual power switch is best to use a temperature protection model.

Ensure that the voltage is always within the safe range during use.

Try to use large current double power switch, can improve the circuit stability performance.

Try to consider the long-term continuous power supply and continuous power supply demand for the output load, and consider its stability.

Precautions & Guide For Automatic Transfer Switch

To prepare for everything and avoid potential risks, it is important to note the following
Considering personal safety and switching speed, the debugging handle is only used for debugging. Users is not allowed use the debugging handle with load operation. And it is not allowed use when the arc extinguishing device is not installed. When debugging, the switch is operated with the debugging handle .To observe the close of the main contact and Running conditions.All are no abnormal situation, then the ATS switch can be work.

After debugging Controller and part of mechanical ,the controller and electrical part can be adjustedof the power-on debugging, the load is prohibited during the debugging process.

Put in the normal power into the products, the normal power indicator is light up, and then put in the standby power ,the standby power indicator is light up. and press the“Manual/Auto” button is placed in the manual position,Then press the "main power manual" button,The ATS will transfer to Main power quickly, The normal power indicator and external connecting indicator lamp is light up.Press the "standby power Manual", The ATS will transfer to Standby power quickly, The standby power indicator and external connecting indicator lamp is light up.

The "Manual/Auto" buttonis placed in the automatic position, delay time of normal power and standby power are adjusted to the appropriate value. The normal power supply is disconnected first, and the indicator of normal power Switch on is flashed on. When reached the setting of delay time value, The ATS will quickly switch to standby power supply automatically.The standby power indicator and external connecting indicator lamp is light up.
When the main power is return,the ATS will switch to Normal power supply, the indicator of standby power switch on is flashes, When reached the setting of delay time value, the ATS will quickly transfer to the normal power supply, The normal power indicator and external connecting indicator lamp is light up.


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