Several square meters is a nominal value stipulated by national standards, and several square meters is used by users to select wires and cables according to the load.
Square wire number is an oral term in the decoration of hydropower buildings. It is often said that a few square lines are square millimeters without units.
1. For the whole bundle of new wires, there will be a wire label on the packaging surface, clearly indicating the brand, model and diameter (number of wires squared) of the wires.
2. Some big brands of wires are printed with brand, model and wire diameter (wire square) on the insulation layer.
3. For unmarked wires, experienced electricians can see the square number of wires by visual inspection.
4, inexperienced people, if you want to judge the thickness of the wire (square), you can use a cursor to measure the diameter of the wire, and then find out the cross section.
How to calculate the square of a conductor
Knowing the square of the conductor, the radius of the conductor is calculated by the formula of finding the circular area: the square of the conductor (square millimeter) = the square of the pi (3. 14)× the radius of the conductor (millimeter).
Knowing the square of the wire is the same as calculating the diameter of the wire. For example, the wire diameter of 2.5 square meters is: 2.5÷3. 14 =0.8, and then 0.9 mm, then the wire diameter of 2.5 square meters is: 2× 0.9 mm =1.8 mm.
Knowing the diameter of the silk, we can also calculate the square of the silk through the formula of finding the circular area: the square of the silk = pi (3. 14)× the square of the silk diameter /4.
The cable size is also the nominal square, and the multi-strand cable is the sum of the cross-sectional areas of each conductor. Calculation formula of cable cross-sectional area: 0.7854 × square of conductor radius (mm )× number of strands. For example, 48 strands (each with a radius of 0.2mm) 1.5 square: 0.7854×(0.2 × 0.2)× 48 = 1.5 square.
Conversion relationship between square number of conductor and current
Safe current carrying capacity of 2.5 mm square copper power cord -28a.
Safe current carrying capacity of 4 mm2 copper power cord -35a.
Safe current carrying capacity of 6 mm2 copper power cord 48a.
10mm2 copper power line -65a's safe current carrying capacity.
16 mm2 safe current carrying capacity of copper power line-91a.
Safe current carrying capacity of 25mm2 copper power cord-120a.
If it is aluminum wire, the wire diameter should be 1.5-2 times that of copper wire.
If the copper wire current is less than 28A, it is definitely safe to use per square millimeter 10A.
If the copper wire current is greater than 120A, it should be 5A/ mm2.
Wire installation specification:
1. General sockets use 2.5 square meters of single-core wires, more than 3 air conditioners use 4 square meters of single-core wires, general incoming wires use 6 square meters of single-core wires, and grounding wires use double-color wires.
2. According to different colors, three volumes are a group (neutral wire, live wire and ground wire), single-core wire for lighting 1.5 square wire, and two volumes are a group (neutral wire and live wire) according to different colors.
3. As an open wire, two-core and three-core sheath line is mostly used for site construction, not for home decoration.
The thicker the audio line, the better. 2* 1.52 or 2* 1.2 is recommended. 5. The more TV distributors are divided, the worse the TV signal. It is suggested to use 6 distribution as much as possible.
5. A built-in household distribution box must be provided at the entrance of each house. The household distribution box is equipped with a main power switch, which can cut off the phase line and neutral line at the same time, and has a disconnect sign. Every house should be equipped with an electric meter, and the electric meter box should be embedded in the wall layer by layer and hidden in the public area.
6. The main switch of the power supply in the household distribution box should adopt a two-pole switch, and the capacity of the main switch should not be too large or too small; It is necessary to avoid tripping at the same time as the disconnector.
7. The watt-hour meter box is usually installed on the public channel in layers, which is convenient for meter reading and management. The embedded wall is installed to avoid occupying public passages.
8, small set (use area shall not be less than 38m.
2) The design power of the electric load is 4KW medium-sized bushing (the usable area is not less than 49m.
2) The design power of electric load is 4.6KW；; Large set (the use area is not less than 59m.
2) The design power of electric load is 6-8kW.
I believe that after the above introduction, everyone has a certain understanding of how to calculate the square of the conductor in the electrical cost. Welcome to Zhong Da for more information.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd