Application guide of the hottest automatic transfe

ATSE application guidelines for automatic transfer switch appliances

1.1 the selection of ATSE technical parameters should be based on the specific use environment (altitude, temperature, humidity, pollution degree, etc.) and the selection of safe and reliable products according to the current national standards and specifications

1.2 it is recommended that the switch body of ATSE meet the requirements of pollution level III (industrial level)

1.3 the rated voltage of ATSE should be compatible with the rated voltage of the circuit (AC is the root mean square value), and the highest or lowest voltage that may appear during normal operation should be considered

1.4 the rated current of ATSE should be greater than the expected working current of the circuit, and it should also carry the possible overcurrent under abnormal conditions

1.5 the rated frequency of ATSE must be compatible with the frequency of the power circuit

1.6 ATSE shall meet the requirements of dynamic stability and thermal stability under short circuit conditions. The CB level ATSE shall meet the breaking capacity under short-circuit conditions, and the PC level ATSE shall bear the requirements of short-circuit withstand current

1.7 when daily maintenance and damage repair still need to ensure continuous power supply, it is recommended to choose bypass isolation type, bypass extraction type ATSE or take other corresponding measures

1.8 PC level ATSE with integrated structure should be adopted for the particularly important load in the first level load

1.9 PC level ATSE is recommended for class I load

1.10 when several ATSE links, they should meet the line protection requirements specified in the code for design of low voltage distribution

1.11 when CB ATSE is used to supply power to the motor, there will be explosion danger under high temperature, short circuit and other conditions, the protection requirements of the motor should be met

1.12 the ATSE used for the conversion of mains power and generator should adopt PC level, integrated structure, three position ATSE. When ATSE with auto switch and auto reset is adopted, the automatic reset shall have appropriate time delay, which can be adjusted to match the shutdown time of the generator

1.13 when it is necessary to automatically cut off the power supply, or with high inductive reactance, or load conversion of large motor, ATSE should adopt three position type; In other places, two position or three position ATSE can be selected as required

1.14 select a reasonable ATSE action time according to the actual engineering needs, and ATSE should be able to avoid the interference of power supply voltage flicker, transient and so on. The total action time of ATSE should refer to table 1.14

table 1.14 maximum allowable interruption time of load (s)

load condition allowable interruption action time of load (s)

computer system, communication system, etc. class a ≤ 0.004

class B ≤ 0.2

class C ≤ 1.5

emergency lighting general places ≤ 5

high risk areas ≤ 0.25

medical equipment class 0 (uninterrupted automatic power supply)

Level 0.15 (very short interval) ≤ 0.15

level 0.5 (short interval) ≤ 0.5

Level 15 (medium interval) ≤ 15

greater than level 15 (long interval) ≥ 15

1.15 ATSE upper and lower action time should be coordinated according to system requirements

1.16 selection principle of ATSE pole number in three-phase four wire system (0.4/0.23kv) power system:

1.16.1 in the same grounding system, the ATSE at the lower level of two power circuits with leakage protection, three-phase four wire power supply should adopt four pole ATSE, and single-phase power supply should adopt two pole ATSE

1.16.2 for ATSE of power conversion between two different grounding systems (including TN-S systems with two different neutral line grounding points), four pole ATSE shall be used for three-phase four wire power supply, and two pole ATSE shall be used for single-phase power supply

1.16.3 when different grounding methods are adopted between the normal power supply and the standby generator, the transfer switch should adopt four pole ATSE

1.16.4 when the neutral line is led out in the IT system, the three-phase four wire power supply should adopt four pole ATSE, and the single-phase power supply should adopt two pole ATSE

1.16.5 under the condition of total equipotential connection, TN-S and TN-C-S systems generally do not need to set quadrupole ATSE except for principles 1.16.1, 1.16.2 and 1.16.3

1.16.6 the TN-C system is strictly prohibited to use the four so testing machine to measure the error of the result, from which pole ATSE

2 requirements for the use of ATSE

2.1 the use category of ATSE should be consistent with the load characteristics and meet the requirements of Table 2.1

Table 2.1 usage category

current property usage category typical use

frequent operation infrequent operation

ac-31a ac-31 B non inductive or micro inductive load

ac-33a ac-33 B motor load or mixed load including motor, resistance load and incandescent lamp load below 30%

ac-35 a ac-35 B discharge lamp load

ac-36 a ac-36 B incandescent lamp load

DC dc-35 The gap between the mixing blade and the bottom of the mixing material pocket and the side wall 1 a dc-31 B resistance load

dc-33 a dc-33 B motor load or mixed load including motor

dc-36 a dc-36 B incandescent lamp load

2.2 when the electrical equipment needs to be powered off for maintenance, testing and repair, the power distribution circuit should be equipped with an isolating appliance. If ATSE meets the requirements of isolating appliances, ATSE can also be used as isolating appliances, otherwise isolating appliances should be added

2.3 in the same level of distribution protection, short-circuit protection appliances should not be set before CB level ATSE

2.4 when the PC level ATSE power supply circuit needs to be equipped with protective appliances, the protective appliances should be set at the incoming side of ATSE (as shown in figure 2.4-1). When used for load side protection, they can be installed at the outgoing side of ATSE (as shown in figure 2.)

figure 2.4-1 figure 2.4-2 figure 2.4-3

figure 2.4 the short-circuit protection appliance of PC ATSE should be set on the incoming side of ATSE

2.5 the power supply of ATSE controller should be taken from the incoming side of ATSE

3 in other

3.1 drawings, ATSE should at least mark the following:

1 rated current

2 type, PC level or CB level

3 pole number

4 total action time

5 digits

6 use category

7 when it is CB level ATSE, release or melt setting current

3.2 PC should also be marked