Automatic Transfer Switching ATSE (AutomaticTransfer Switch Equipment), is a commonly used electrical switchgear, main role is to select between the two available power supply, all the way to safe and reliable power supply to the load, in order to ensure the continuity of the electricity load. Since With dual power supply to the load distribution system, there is a dual power automatic transfer switch applications. The ATSE National standard with GB/T14048.11 of China"s relevant departments issued on October 8, 2002 with effect from April 1, 2003. This standard is equivalent to the standard of the International Electrotechnical Commission IEC60947-6-1. This article will closely combined with GB/T14048.11 standard, integrated design and use of existing problems, especially the tender technical requirements, the ATSE requirements and limited, do the following preliminary elaboration and discussion.

1, the automatic transfer switch definition

The definition of GB/T14048.11: automatic conversion of electrical switches ATSE by one (or several) transfer switching equipment and other necessary appliances, used to monitor the power supply circuit, and one or several load circuit from a power supply automatically converted to another electrical power. We can understand the definition as follows:

(1) ATSE is an independent electrical switch
It tied in circuit breakers, load switches, fuses, contactors, electrical switches, electrical parameters required.

(2) ATSE by the changeover switch and the corresponding monitoring, control and other electronic circuits

That is to say, the only complete the ATS main switch plus matching controller in order to constitute ATSE.

(3) by ATSE supporting, control agencies to monitor their own two-way power supply situation

The main parameters should be monitored power supply voltage and frequency is generally understood, but the standard does not explicitly pointed out that should be monitored is a three-phase or single-phase voltage / frequency. For designers, ATSE lack of phase transformation, ATSE controller with dual three-phase detection function.

(4) the conversion process is done automatically

ATSE controller will detect the actual situation of dual power, pre-stored in the controller set to do a comparison and logical judgment, and then make the drive converter control command.

(5) This conversion is completed in two-way power

Current power supply system for emergency load most of the two-way power with one standby, but there are three power supply system with two. For such a system can not rely solely on a ATSE to complete the conversion. The solution is: two ATSE combination completed or three circuit breakers (Note that if there is a mechanical linkage) external control and electrical chain.

2 ATSE the classification

Based on national standards, ATSE only one classification: PC-class and class CB. The market often say "two-stage", "three-step" ATSE is a misnomer.

PC-class ATSE is only completed dual power automatic transfer function, rather than have the short-circuit current breaking; CB level ATSE is either completed dual power conversion, but also have the function of the short-circuit current protection.

PC and CB-level ATSE own advantages and disadvantages, can not simply measure the PC and CB-level in the end which one is better. Design and user according to the habits and system requirements to select the level of ATSE, in conjunction with other electrical components to set up emergency power supply system.

3, ATSE basic technical parameters

As an electrical switch, ATSE some basic technical parameters and requirements, which is the design should pay attention to the details and the preparation of technical points that should be included in the tender technical documents:

(1) Level

The selection and use of ATSE, we must first determine the level PC level or CB level. This will affect the future how to choose ATSE short-circuit characteristics.

(2) The rated voltage, rated current, rated frequency, switch Number of poles

These electrical technical parameters, we are familiar with the electrical parameters of the circuit breaker will not go into here.

(3) Use Category

Use category classification of the type of load.