How to check the symmetry of the core section of the insulated cable round cable

The nominal voltage of China's transmission system should be 30kV, and the single-phase (core) XLPE insulated power cable is 18 30 (36) kV for class A and B, and 21 30 (36) kV for class C.

For YJV 18 30(36)KV 1X300 copper core single core XLPE insulated PVC sheathed power cable:

The maximum allowable DC resistance at 20°C is:

18 30 (36) single core cable (YJV) in the work imitation of the conductor AC resistance at the temperature:.

Specific data can be requested from the cable manufacturer or consulted with the manufacturer.

Generally judged by experience! If you want to know very accurately, use vernier calipers to measure the diameter of the circle area! If it's multi-core, you can add it up separately!

This depends on what kind of cable you have, and the national standard standard has no hard requirements for the copper wire used. Rubber cables are generally national standard copper wires. The general national standard of plastic cable is 250 wire.

If you want to check the loss side of the cable. Its monofilament diameter can be measured and its root count can be counted. Then use the formula to figure out its actual square.

Now there should not be many first-class cables on the market that do not lose money. You can measure the outer diameter of a single copper wire, count the number of roots, and use the number of roots * the area of the single wire to get the total cross-sectional area.

This is really difficult, and it can only be measured approximately, and it is estimated that the general cable is at a loss. Measure the diameter of a single core, count the number of roots, and see if it's okay.

Measure the diameter of a single core, count the number of roots, and calculate the cross-sectional area. It also depends on the quality of the home.

The general copper wire safety calculation method is:

The safe ampacity of the square millimeter copper power cord is 28A.

The safe ampacity of the 4 square mm copper power cord is 35A.

The safe ampacity of the 6 square mm copper power cord is 48A.

The safe ampacities of the 10 square mm copper power cord are 65A.

The safe ampacity of the 16 square mm copper power cord is 91A.

The safe current carrying capacity of the 25 square mm copper power cord is 120A.

Commonly used wire power comparison table: how big the wire is, how much power it can withstand, at a glance.

The first thing to do is to calculate the wire current, according to the three phases.

The formula for power:

p = 80kw:

80kw=i=80kw/

i=120kw:

120kw=

i=120kw/

i= The power factor here is taken as the power factor, and if the power factor is taken as or, the calculated current is even smaller. Usually the motor is not particularly advanced and calculated.

Also consider the starting current, the starting current of the motor is larger than the rated working current, generally 4 7 times of the rated current, but the time is not very long, so it is usually taken as many times of the working current. Here's a double.

Also take into account the usage factor, as your appliances are not used at the same time, and how likely it is that they will be used at the same time. Only one motor will take 1, and the number of motors will be small if the number of motors is used at the same time.

If it is 80kw, it can be considered according to the current of 170A line, and electrical components such as cables and air openings can be selected.

The selection of cables should be selected according to the laying conditions, and the current carrying capacity of the same cross-section wires of different manufacturers is about the same.

According to the power cable ampacity meter of a manufacturer, 80kw can choose copper core 50 square three-core or four-core cable.

The simplest algorithm is to take 6 amps of current from a square line.

Use as thick a wire as the current is.

For mains 20000 220 = 90aAs long as the current capacity is more than 90 amps, 25 square mm aluminum wire or 16 square mm copper wire can be selected.

For industrial and electrical 20000 380 = 53a. You can choose wires with a cross-sectional current capacity of more than 53A, and you can choose 3 aluminum wires or copper wires of 10 square mm.

The voltage is calculated as 220V and multiplied by the current (e.g., 20A, 12A,。。 The number obtained is the power (W is described).

Your question seems simple, but it's troublesome to make it clear. The current carrying capacity of copper core cable is larger than that of aluminum core, and the single core is larger than that of polycore, and the large multiple is not regular. The current carrying capacity is also very related to the laying method of the cable and the ambient temperature, the buried is a little larger than the air, the ambient temperature is a little higher, and the current carrying capacity is also a little larger.

Because the cross-sectional area is too small, only squared, and the current carrying capacity is not large, so the relative change of the larger point mentioned above is relatively large. Copper core multi-core cable can be estimated at 25A, single core can be estimated at 30A, aluminum core multi-core cable can be estimated at 18A, single core can be estimated at 23A, multi-core laying wiring is convenient, three-phase length is the same, heat dissipation is not good, so the current carrying capacity is smaller; Single-core laying wiring is troublesome, and there are more fault points when there are more lines, but the current carrying capacity is a little larger. The safety current that 1 square copper wire can withstand is 5A, and the general copper wire safety calculation method is:

The safe ampacity of the square millimeter copper power cord is 28A. The safe ampacity of the 4 square mm copper power cord is 35A. The safe ampacity of the 6 square mm copper power cord is 48A.

The safe ampacities of the 10 square mm copper power cord are 65A. The safe ampacity of the 16 square mm copper power cord is 91A. The safe current carrying capacity of the 25 square mm copper power cord is 120A.

If it is an aluminum wire, the wire diameter should be times that of the copper wire. If the copper wire current is less than 28A, it is definitely safe to take 10A per square millimeter. If the copper wire current is greater than 120A, it will be taken as 5A per square millimeter.

The current that can pass through the cross-sectional area of the wire can be selected according to the total amount of current that needs to be turned on, and can generally be determined according to the following slip: But there is no formula. Ten under five, one hundred on two, two five three, five five, five five, five five and a half times, copper wire upgrades.

Let me explain to you, it is an aluminum wire of less than 10 square meters, multiply the number of square millimeters by 5, if it is a copper wire, it will be upgraded by a gear, such as a square copper wire, it will be calculated according to 4 square meters. More than 100 are multiplied by 2 for the cross-sectional area, multiplied by 4 for those below 25 squares, multiplied by 3 for more than 35 squares, multiplied by 95 squares, such a few mantras should be easy to remember, I hope it will help you.

Thank you for the trouble to adopt!

Be sure to use the original one, don't use your own match, which will run the electricity.