Wire cross-section for wiring

Electricity is so firmly incorporated into ourlife, that when a sudden power outage, our life seems to freeze, and we look forward to it being restored. We are surrounded by a huge number of various electrical appliances, which are connected to the home network either directly through sockets or through

extenders or carrying.

Sometimes you need to hold the light in the garage or inanother household building, replace the wire or make a homemade extension cord. Or you need to calculate what the maximum number of devices can be simultaneously included in one tee, so that the wire does not heat up in it and a fire does not occur due to a short circuit. In such cases, you must first make a calculation of the cross-section of the wires in order to be confident in the safety of the installed electrical wiring.

Which wire to choose?

It is no secret that copper has lessresistance compared to aluminum, and therefore if we compare copper and aluminum wiring, which have the same wire cross section, in the first case, the permissible load will be somewhat greater. Copper wire is stronger, softer and does not break in places of inflection. In addition, copper is less susceptible to oxidation and corrosion. The only advantage of aluminum wire is its cost, which is three times or four times less than copper.

Calculation of wire cross-section for power

Any wiring must complyconnected to her load. The wire cross section is calculated based on the maximum allowable heating of the conductor. The amount of heating depends on the power of the connected electrical appliances. Thus, by calculating the maximum possible total power of devices in the room, you can determine what should be the cross section of the wire. In practice, it is convenient to use an online calculator or special tables that contain information about the allowable current load on the cable.

Wire gauge, mm	Copper wire (cable, lived)
	Voltage in the circuit, 220 V		Voltage in the circuit, 380 V
	power, kWt	current, A	power, kWt	current, A
1.5	4.1	19	10.5	16
2.5	5.9	27	16.5	25
4	8.3	38	19.8	30
6	10.1	46	26.4	40
10	15.4	70	33.0	50
16	18.7	85	49.5	75
25	25.3	115	59.4	90
35	29.7	135	75.9	115
50	38.5	175	95.7	145
70	47.3	215	118.8	180
95	57.2	260	145.2	220
120	66.0	300	171.6	260

Wire gauge, mm	Aluminum wire (cable, core)
	Voltage in the circuit, 220 V		Voltage in the circuit, 380 V
	power. kw	current strength BUT	power. kw	current strength BUT
2.5	4.4	20	12.5	19
4	6.1	28	15.1	23
6	7.9	36	19.8	30
10	11.0	50	25.7	39
16	13.2	60	36.3	55
25	18.7	85	46.2	70
35	22.0	100	56.1	85
50	29.7	135	72.6	110
70	36.3	165	92.4	140
95	44.0	200	112.2	170
120	50.6	230	132.0	200

How to check the wire size?

Since the wires most often have a round cross-sectional shape, the area of ​​the slice is calculated by the formula:

S = π x d² / 4 or S = 0.8 x d², where
S is the cross-sectional area of ​​the core in mm.kv .;
π - 3.14;
d - core diameter in mm.

Suppose, for example, that the diameter of the wire is 1.3 mm., Then S = 0.8 • 1.3² = 0.8 • 1.3 x 1.3 = 1.352 mm.kv.

If the wire consists of several wires, thenthe cross section of one conductor is considered and multiplied by their total number in the bundle. The diameter is usually measured with a caliper, but if it is not, then the usual ruler will do. In this case, about 10-15 turns are tightly wound on a pencil, the length of the winding is measured with a ruler, and the resulting value is divided by the number of turns.

For any electrical work you need to rememberthat electricity does not tolerate negligence and does not forgive mistakes. Electrical safety and reliability - this is what you should always strive for in any work with electrical wiring in the apartment, in the country or in the house.