What Is a Wire Room?

Wires and cables are used to transmit electrical (magnetic) energy, information, and wire products for electromagnetic energy conversion. The wire and cable in a broad sense are also simply called cables. A narrow cable refers to an insulated cable. It can be defined as: an assembly composed of the following parts; one or more insulated wire cores, and their respective coatings. The protective layer and the outer protective layer, and the cable may also have additional uninsulated conductors.

Wire and Cable

Wires and cables are used to transmit electrical (magnetic) energy, information and implementation

Wire and cable products are mostly cross-section (

Costing formula

YJV cost price calculation formula

YJV copper core power cable series cost price formula is as follows:

Copper weight X copper price calculation:

Wire diameter ÷ 2 = 1.25X1.25X3.14

= Square number X number of wires X0.89X at that time copper price + 10% processing fee.

Calculation formula of cost price of rubber sheathed cable

Square X1.83 = weight of copper X copper price at that time + rubber price (weight X 0.4 yuan / kg) = cost price + 10% processing fee

The price of the cable = cost of manufacturing materials + fixed costs + taxes + business fees + profit

Manufacturing material cost = material cost * (1 + material consumption) (material cost is the value calculated theoretically)

The fixed fee varies according to the situation of each company, and generally includes production wages, management wages, utilities, repairs, depreciation, rent, and transportation costs.

Ampacity calculation formula

Estimation formula

Multiply it by 2.5 and multiply it by nine.

Thirty-five times three-five, both of which are reduced by five.

Conditions are subject to change and discount, and copper at high temperature can be upgraded by 10%.

The number of through-pipes is two-four-four, eighty-six percent full load.

Note: The formula in this section does not directly indicate the current carrying capacity (safety current) of various insulated wires (rubber and plastic insulated wires), but instead means "section multiplied by a certain multiple" to obtain it through mental arithmetic. It can be seen from Table 53 that the multiple decreases as the cross section increases.

Multiply by 2.5 and nine, and go up by one.

"Multiplying by two and five times nine, and subtracting one from the other." It is said that the aluminum core insulated wires of various cross sections of 2.5 mm 'and below have a current carrying capacity of about nine times the number of cross sections. For 2.5mm 'wire, the current carrying capacity is 2.5 × 9 = 22.5 (A). The multiple relationship between the current carrying capacity and the cross section of the conductors from 4mm 'and above is to line up along the line number, and the multiple is decreased by 1, which is 4 × 8, 6 × 7, 10 × 6, 16 × 5, 25 × 4.

Thirty-five times three-five, both of which are reduced by five.

"Thirty-five times three point five, both points are reduced by five points," said 35mm ", the current carrying capacity of the wire is 3.5 times the number of sections, that is, 35 × 3.5 = 122.5 (A). From For conductors of 50mm 'and above, the multiple relationship between the current carrying capacity and the number of sections becomes two sets of two wire numbers, and the multiples are reduced by 0.5 in sequence. That is, the current carrying capacity of 50 and 70mm' conductors is 3 of the number of sections. Times; the current carrying capacity of the 95, 120mm "wire is 2.5 times its cross-sectional area, and so on.

Conditions are subject to change and discount, and copper at high temperature can be upgraded by 10%.

"Conditions are subject to change and discounts, and copper at high temperature is up to 10% off." The above formula is based on the aluminum core insulated wire, exposed to the environment temperature of 25 . If the aluminum core insulated wire is applied in an area where the ambient temperature is higher than 25 ° C for a long time, the current carrying capacity of the conductor can be calculated according to the above calculation method, and then a 10% discount can be used. When not using aluminum wire but copper core insulated wire, Its ampacity is slightly larger than that of the aluminum wire of the same specification. According to the above formula, the ampacity of the aluminum wire is increased by one line number. For example, the current carrying capacity of 16mm 'copper wire can be calculated as 25mm2 aluminum wire.

The number of through-pipes is two-four-four, eighty-six percent full load.

In the case of "two, three, four, seventy-six percent full load carrying pipe", two, three, and four wires are laid through the pipe, and the current carrying capacity is 80% of the calculated current carrying capacity of the electrical outlet (single installation). , 70%, 60%.

Appearance standards, the certification mark, manufacturer, wire diameter, etc. must be on the wire, and the yellow-green insulation layer for the ground wire

Mechanical strength

Sheath insulation (generally greater than 100M) and compressive strength (500V to 1500V)

Wire resistance (not more than a certain resistance under a certain wire diameter, conductivity, and length)

The wire must not crack under the high temperature impact of 140 degrees and the low temperature of -30 degrees.

As the main carrier of power transmission, wires and cables are widely used in electrical equipment, lighting circuits, household appliances, etc. The quality of wires and cables directly affects the quality of engineering and the safety of consumers' lives and property. There are many types of wires in the market, and you should use the right wires according to your electrical load.
Some of the wires sold in the market are cheaper and some are more expensive. Some people tend to be cheaper first. However, there are often a lot of cheap wires that do not reach the performance that he explained, and they may bring themselves. Many security risks. The production technology content of the wire is not too high, and the raw materials are not much different. If it is too cheap, it will either be cut corners or the quantity will not be enough. Then how to identify it. Let me tell you a few easy ways to identify:
1. For the packaging, the national standard wires are usually better, neat, and have a sense of quality.
2. Open the package and take a look at the wires inside. The national standard wire 1.5-6 square wire requires a skin thickness (insulation thickness) of 0.7mm. If it is too thick, it is non-standard, and his inner core will be sure. Not enough, you can pull the line hard. The one that is not easy to tear is the national standard 3. It is burned with fire and extinguished within 5s after leaving. It is a national standard line with a certain flame retardant function.
4. Look at the inner core. The higher the brightness of the inner core material (copper), the better the copper, and the uniformity, luster, and no sense of layering. The national standard requires that the core must use oxygen-free copper. Non-standard items such as black rod copper may have hidden dangers.
5, the thickness of the core country has certain requirements, but not very strict. But it won't make a lot of mistakes, it's just a little bit, the error that can't be seen by the eyes.
6, length, the country does not have to beat rice, but there are many manufacturers also beat the meter, the meter is not necessarily the national standard, but the general national standard is generally not metered. Non-standard hit rice is just a means.
7. The state stipulates that there must be a certain mark on the wire. The maximum mark will not be more than 500mm, there will be the next same mark. There are generally product trademarks, manufacturer names, implementation standards, etc.

1. Guarantee the construction quality, especially the quality of the cable head must strictly comply with the requirements.

2. Strengthen cable operation monitoring to avoid cable overload operation.

3. Carry out the cable test on schedule and deal with it when it is found abnormal.

4. The cable trench should be kept dry to prevent the cable from getting wet, causing the insulation to fall and causing a short circuit.

5. Regularly clean up the accumulated dust on the cable to prevent the accumulated dust from spontaneously igniting and causing the cable to catch fire.

6. Strengthen the regular check and maintenance of the cable loop switch and protection to ensure its reliable operation.

7. When laying the cables, keep a sufficient distance from the heat pipes, the control cable is not less than 0.5 meters, and the power cable is not less than 1 meter. Control cables and power cables should be separated, arranged in layers, and separated, and should not be placed between layers. For the parts that do not meet the requirements, the cable shall be fire-retardant and heat-insulated.

8. Install a fire alarm device to detect the fire in time to prevent the cable from catching fire.

9. Take fire retardant measures.

The cable gland is a suitable power source for connecting cables and also protects the cables so it will not escape. Cable glands are placed in different categories, depending on whether the glands are used in the general processing industry or need protection from the danger of overheating or explosion. The glands are cable armored or unarmoured and a different type of gland will be required for each variety. The gland itself can be made of metal, such as copper or aluminum, or plastic, and each material is useful in different environments.

When the electrical work is complete, it may be without cable seals to secure the electrical equipment wires, but there are several reasons why this is a bad idea. The gland provides sealing power, ensuring that the cable does not slip during operation. Safety is also provided because the glands ensure that electrical energy can not be attached to cables near anyone, causing personal injury. Glands often provide other safety features, such as ground wires or insulated cables.

There are two broad categories for cable sealing: industrial and hazardous. Industrial cable gland is a general purpose gland to meet the requirements of general hazards, so it is useful for use in high temperature environments or the danger of explosion. If the environment is hazardous, use dangerous glands, as these glands meet the necessary additional requirements. They are additional reinforcements that make them resistant to temperatures and external forces that the normal glands cannot tolerate.

Two types of cables can be put into the cable glands and are classified as armored or unarmored, which will play a role in the glands and will pick up. The armored cable will require a gland that can be clipped to the wire and has the ability to terminate the energy from the armored part. Unarmored wire does not require termination, but the glands need to be highly protected and retained to keep the wire safe.

Most cable gland units are made of brass, which is considered to be corrosion resistant and conductive as a general material. In the presence of aluminum and moisture, at the same time, brass can begin to corrode. Brass is often plated with other metals to make the glands stronger and better resistant to corrosion. Plastic is often used as an alternative metal gland.