First, the general copper terminal connector load capacity terminal connector peace of load capacity is based on the permitted maximum temperature of the core, cooling conditions, laying conditions to determine the general copper terminal connector peace of load capacity of 5~8A/mm2 Aluminum terminal connector peace of load capacity of 3~5A/mm2 Key point > General copper terminal connector Connector safe load capacity of 5~8A/mm2 Aluminum terminal connectors safe load capacity of 3~5A/mm2 such as: 2.5 mm2 BVV copper terminal connectors safe load capacity of the recommended value of 2.5 8A/mm2 = 20A 4 mm2 BVV copper terminal connectors safe load capacity of the recommended value of 4 8A/mm2 = 32A
Second, the calculation of copper Terminal block connector cross-sectional area using copper terminal block connector safe load capacity of the recommended value of 5~8A/mm2 Calculate the selected copper terminal block connector cross-sectional area S up and down range: S = I / 5~8 >=0.125 I ~ 0.2 I mm2 S----- Copper terminal block connector cross-sectional area (mm2 I----- Load current (A
General Terminal block connector cross-sectional area and load current calculation
Third, the power calculation of the general load (can also be electrical appliances, such as lights, refrigerators, etc.) is divided into two kinds, a type of resistive load, an inductive load. For the resistive load formula: P = UI for fluorescent lamp load formula: P = UIco ф, where the fluorescent lamp load power factor co ф = 0.5 power factor of different inductive loads are different, unified calculation of household appliances can be the power factor co ф 0.8 That is to say, if all the appliances in a household plus the total power of 6,000 watts, then the maximum current I= P/Uco ф = 6,000 watts, then the maximum current is I= P/Uco ф = 6,000 watts, then the maximum current is I= P/Uco ф = 6,000 watts. P / Uco ф = 6000/220 * 0.8 = 34 A But in general, the home appliances can not be used at the same time, so add a common coefficient, common coefficient is generally 0.5 So, the above calculations should be rewritten as I = P * common coefficient / Uco ф = 6000 * 0.5/220 * 0.8 = 17 A That is to say, the total value of the family's current for the 17A. The main air switch can not be used 16A should be used more than 17A
General terminal connector cross-sectional area and current-carrying capacity of the calculation
Estimation of the mnemonic:
2.5 multiplied by nine, minus one upward to the number.
Thirty-five times 3.5, two pairs minus 5.
The conditions have changed, so you can get a 10% discount on high temperature.
The number of tubes is two, three, four, eight, seven, six percent off the full load flow.
Description:
1 This section of the mnemonic on the various insulated wire (rubber and plastic insulated wire) current carrying capacity (safe current) is not directly pointed out, but the cross-section multiplied by a certain number of times " to indicate that, through the heart of the calculation. As can be seen from Table 5 3: the multiplier decreases as the cross-section increases.
General terminal connector cross-sectional area and current-carrying capacity of the calculation
2.5 multiplied by nine, up minus one to go along with the number " said 2.5mm and below, a variety of cross-sectional area and the following. 5mm and the following cross-section of various aluminum core insulated wire, its current-carrying capacity of about 9 times the number of sections. Such as 2.5mm terminal block connector, the carrying capacity is about 9 times the number of sections. For example, for a 2.5 mm terminal block connector, the current-carrying capacity is 2.5 9 = 22.5 mm. 5.9 = 22.5 A 5 A from 4mm and above terminal connectors and the cross-section of the number of multiples of the relationship between the number of lines up row, the multiplier is reduced l that 4 8 6 7 10 6 6 16 5 25 4
Thirty-five times three point five, double double into the group minus point five " said 35mm terminal connectors for the number of cross-section of the load capacity of 3.5 times, that is, 35 3.5 times the number of cross-section of the connectors. 5 times, i.e. 35 3.5 = 122.5 times. 3.5 = 122.5 A 5 A from 50mm and above the terminal connectors, its load capacity and the number of cross-section of the multiplier relationship between the two two line number into a group, the multiplier is reduced by 0.5. 5 that is, 50 70mm terminal block connector load capacity for the number of sections of 3 times; 95 120mm terminal block connector load capacity is the number of its cross-sectional area of 2.5 times, and so on. 5 times, and so on.
Conditions have changed plus discount, high temperature discount copper upgrade " The above mnemonic is an aluminum core insulated wire, laying in the ambient temperature of 25 ℃ under the conditions set if the aluminum core insulated wire laying in the ambient temperature is temporarily higher than 25 ℃ in the region, the terminal block connector load capacity according to the above mnemonic method of calculating, and then discounted can be; when the use of non-aluminum but copper wire, the load capacity is the number of cross-sectional area, and so on. When not using aluminum wire but copper-core insulated wire, load capacity than the same specification aluminum wire slightly larger, can be calculated according to the above mnemonic method than the aluminum wire to increase the load capacity of a line number. Such as 16mm copper wire, can be calculated according to 25mm2 aluminum wire
Terminal connector selection: a square of copper wire for 6A, a square of aluminum wire for 4A
Terminal connectors and the terminal connector cross-section of the current-carrying capacity of the connector, but also with the terminal connector information, type, laying method and ambient temperature and so on, affecting the more factors, the calculation is also more complicated. Calculation is also more complex. A variety of terminal connectors of the current-carrying capacity can usually be found in the manual. But the use of mnemonics with some simple calculations, you can directly calculate, without having to check the table.
1. Mnemonic Aluminum core insulated wire current-carrying capacity in relation to the multiples of the cross-section
10 lower five, 100 upper two,
25 35 four, three boundaries, .
70 95 two and a half times .
20% to 90% off on tubing and temperature.
Bare wire plus half.
Upgrade for copper.
2. Description The mnemonic for the various cross-section of the current-carrying capacity (ampere) is not directly pointed out by the cross-section multiplied by a certain number of times to indicate. This will be commonly used in China terminal connector nominal cross-section (square millimeters) is arranged as follows:
Terminal connector selection: a square of copper wire for the 6A, a square of aluminum wire for the 4A
1 1.5 2.5 4 6 10 16 25 35 50 50 95 120 150 185
1 The first mnemonic pointing out that the aluminum core insulated wire current-carrying capacity (ampere) can be multiplied by the cross-section of the multiplier to indicate the number of times. ) can be calculated as a multiple of the cross-section. The Arabic numerals in the mnemonic indicate the cross-section of the terminal connector (square millimeters) and the Chinese numerals indicate the multiplier. Clearly the mnemonic " 10 under five " means that the cross-section of 10 below, the current-carrying capacity are five times the value of the cross-section. 100 on two " read 100 on two. 100 on two " (pronounced 100 on two) means that the cross-section of more than 100 load capacity is two times the value of the cross-section. The cross-section is divided between 25 and 35 quadruples and triples. This is the mnemonic " 25 35 four and three times " and the cross section 70 95 is two and a half times. It can be seen from the above arrangement: in addition to the following 10 and more than 100, the middle of the terminal connector cross-section of each two specifications belong to the same kind of multiples.
For example, aluminum insulated wire, the ambient temperature is not greater than 25 ℃ when the calculation of current-carrying capacity:
When the cross-section of 6 square millimeters, the calculated current-carrying capacity of 30 amps;
When the cross-section of 150 square millimeters, the calculated current-carrying capacity of 300 amps;
Terminal connector selection: 6 amps of a square of copper wire, a square of aluminum wire for 4 amps.
When the cross-section of 70 square millimeters, the calculated current-carrying capacity of 175 amps;
From the above arrangement can also be seen: multiples of the cross-section increases and decreases, the multiples of the junction of the transition, the error is slightly larger. For example, at the point where the cross-section of 25 and 35 is divided into four times and three times, 25 is in the range of four times, which is 100 amperes according to the mnemonic, but 97 amperes according to the manual, while 35 is the opposite, which is 105 amperes according to the mnemonic, but 117 amperes according to the table. However, this does not have a significant effect on usage. Of course, it would be more accurate to choose the terminal block cross-section so that the 25 does not reach the full 100 amperes and the 35 slightly exceeds 105 amperes. Similarly, a 2.5 mm2 terminal block connector positioned at the beginning of the five times, in fact, is more than five times (up to a maximum of 20 amperes or more), but in order to minimize the electrical power inside the terminal block connector, it is necessary to use a 2.5 mm2 connector with a maximum of 20 amperes, which is not the same as a 2.5 mm2 connector. However, in order to minimize the power loss in the terminal block connector, the current is usually not that high and is usually labeled as 12 A in the manual.
2 The last three mnemonics are the treatment of changing conditions. Through the pipe, temperature, eight, 90% discount " means: if it is laid through the pipe (including groove boards and other laying, that is, the terminal connector with a protective jacket layer, not exposed to the calculation, and then 20% discount; if the ambient temperature of more than 25 ℃, the calculation of another 90% discount, if both through the pipe laying, the temperature is more than 25 ℃, then 20% discount and then 90% discount, or simply according to the one time to play a 70% discount calculation.
The choice of terminal connectors: a square of copper wire for 6A, a square of aluminum wire for 4A
On the ambient temperature, according to the regulations refers to the average maximum temperature of the hottest month of summer. In fact, the temperature is changing in general, the impact of the terminal connector current-carrying is not very large. Therefore, only some of the temperature workshop or hotter areas more than 25 ℃, only when the discount is considered.
For example, the aluminum core insulated wire in different conditions to download the flow of the calculation:
When the cross-section of 10 square millimeters through the tube, then the current-carrying capacity of 10 5 0.8 ═ 40 A; if the high temperature, then the current-carrying capacity of 10 5 0.9 ═ 45 A; if it is a high temperature through the tube and, then the current-carrying capacity of 10 5 0.7 ═ 35 A.