BTTZ mineral insulated cable and BTTW cable difference, which one expensive?
BTTZ and BTTW are both copper sheath, copper conductor, mineral insulated fire cable, these two kinds of cable are the best fire cable. BTTZ was invented before BTTW, so what are the similarities and differences between them?

1. Comparison of cable structure between BTTZ and BTTW:

BTTZ USES copper sheath, copper conductor (copper rod) insulation layer is magnesium oxide powder. BTTW also USES copper sheath (the copper belt is round in the mold, after covering the cable core, argon arc welding, continuous rolling grain) copper conductor (multi-strand copper wire stranded), and the insulation layer is magnesium oxide and other inorganic minerals wrapped on the conductor. Due to the great difference in the structure of the two cables, their production technology and characteristics are very different.

2.Comparison of cable manufacturing process:

BTTZ manufacturing process is complex, low degree of mechanization, high energy consumption. BTTZ currently has two processes. One is to prefabricate magnesium oxide powder into a porcelain column and insert it into a fixed length copper tube and a fixed length conductor. After annealing, drawing, drawing and drawing until the conductor is fixed. Another process is continuous pouring powder (magnesium oxide) in the length of copper pipe, still annealing while drawing to the specified specifications. For the cable drawing of small section, the length is longer, while the cable drawing of large section is shorter, so the intermediate joint must be added. At the same time, the cable body is very hard and is of rigid structure. The production process of BTTW cable is advanced, and the whole production process is completed by automatic production line. The stranding of copper conductor and insulation wrapping are completed at the same time in the machine. The semi-finished products are put into the oven to get wet and then welded by argon arc welding. The rolling pattern is also completed at the same time in mechanization. Therefore, the BTTW cable is of good quality without human factors, and the BTTW cable can be continuously produced with a long length, flexible and large and small section, which can be coiled on the standard cable disc.

3.Comparison of electrical characteristics:

1)Compared with the cable impedance, the BTTZ impedance is relatively large, and its conductor has thickness in processing (in the drawing process, the conductor is squeezed by magnesium oxide powder, so the magnesium powder is tight and loose, which determines the conductor has thickness and thickness. Second, there are pitted spots and oxide film on the surface of the conductor, the actual conductor section can not reach the nominal section.
2)Dynamic and thermal stability the thermal stability of the two types of cable "bodies" is top grade, without checking calculation. The thermal stability of the BTTZ joint is not very reliable. When the short-circuit temperature is greater than 200℃, it cannot be resisted. In general, the short-circuit temperature is greater than 200℃. As for the dynamic stability of the two kinds of cables, BTTZ is a rigid structure and must pass the dynamic stability test. The test medium must have at least one joint. According to the joint structure, it is difficult for BTTZ to pass the dynamic stability test.
3)single-core cable and multi-core cable, BTTZ has no uniform multi-core cable, the so-called maximum to 4*25mm2 multi-core cable, its three-phase impedance is not uniform, can only be called four single-core cable together. BTTW has multi-core cable with uniform impedance up to 4* 70mm2. The electrical performance of multi-core cable is better than that of single-core cable. Generally speaking, single-core cable will generate eddy current in operation, causing copper loss and not saving energy.
4)trunk type distribution and chain distribution, distribution methods are radiation type (large amount of cable) and trunk type (cable saving). BTTZ cannot use trunk distribution.
5)electric strength, BTTZ electric intensity in the straight line segment is better, but in the curved section, bending the inside of the magnesium powder insulation rather closely, pressure increased, the bending of the lateral, magnesium powder insulation cracking, reduces the electrical strength, and in the middle connector or terminal joints airtight, moisture immersed, electric intensity is greatly reduced, BTTW mineral belt is moisture and not cracking, dielectric strength is always stable.
Mineral insulated cable BTTZ, BTTW (YTTW), BTLY, BBTRZ core number and section specifications
BTTZ 25 square above single core cable, generally recommended to make multi - core. In mineral insulated cables, BTTZ and YTTW have no five cores because their seamless copper sheath can be used as a ground wire. Other models can be made five core mineral cable.
BTTZ mineral insulated cable and BTTW cable difference, which one expensive?

4. Service life comparison of mineral cable:

Service life of the cable body, no difference between the two types of cable, no problem over 50 years;
cable joint, BTTZ joint material is not inorganic, can maintain a life of 30 years is quite good, because the aging of organic matter is inevitable. The whole system of BTTW is made of inorganic material, which can avoid rapid aging damage.

5. price comparison between BTTZ and BTTW cable

The price of raw materials, BTTW is slightly higher than BTTZ, because the price of copper wire strand is higher than that of copper rod; The price of mineral belt is higher than mineral powder; Obviously, the price of BTTW is slightly higher than that of BTTZ.
Manufacturing cost: the manufacturing process of BTTZ is relatively backward and complex, with advanced btt-resistant technology, mechanized production, less labor, faster speed and low waste, so the manufacturing cost of BTTW is lower than that of BTTZ.
cable accessories, BTTZ accessories more expensive, BTTW accessories less low price.
Installation cost: BTTZ is larger than BTTW. The price of BTTZ ontology plus accessories and labor cost is slightly higher than that of BTTW.